ABCMdb

ABCA3 p.Leu101Pro

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Publications

PMID: 21567408 [PubMed] Nakagawa H et al: "Ubiquitin-mediated proteasomal degradation of ABC transporters: a new aspect of genetic polymorphisms and clinical impacts."

No. Sentence Comment

155 Effect of Mutations and Nonsynonymous SNPs on Protein Trafficking, Maturation, or ERAD of ABC Transporters Protein AA Mutation/SNP Effect on Protein Reference ABCA1 W590S Mutation Functional defect 115 R587W Mutation Impaired glycol processing 115 Q597R Mutation Impaired glycol processing, ERAD 115,116 Y1532C Mutation Altered protein trafficking 117 R1925Q Mutation Altered protein trafficking 118 ABCA3 R43L Mutation Altered protein trafficking 119 L101P Mutation Altered protein trafficking 119 R280C Mutation Altered protein trafficking 119 ABCA4 L541P Mutation Mislocalization 120 R602W Mutation Mislocalization 120 A1038V Mutation Mislocalization 120 C1490Y Mutation Mislocalization 120 ABCB1a G268V Mutation ERAD 121 G341C Mutation ERAD 121 I1196S Mutation Reduced glycosylation 122 ABCB4 I541F Mutation Accumulation in ER 123 ABCB11a E135K Mutation Reduced level of mature protein 124 L198P Mutation Reduced level of mature protein 124 E297G Mutation Reduced level of mature protein 124 L413W Mutation Reduced level of mature protein 124 R432T Mutation Reduced level of mature protein 124 D482G Mutation Immature protein in ER 124,125 N490D Mutation Reduced level of mature protein 124 A570T Mutation Reduced level of mature protein 124 T655I Mutation Reduced level of mature protein 124 Y818F SNP Moderate reduction of protein 124 G982R Mutation Retention in ER 125 R1153C Mutation ERAD 125 R1286Q Mutation Retention in ER 125 ABCC2a R768W Mutation Impaired protein trafficking 126 I1173F Mutation Impaired protein maturation 127 R1392 Mutation Impaired protein maturation 128 M1393 Mutation Impaired protein maturation 129 ABCC4a E757K SNP Altered protein trafficking 23 ABCC7 F508 Mutation Misfolding, ERAD 36-39,130 G85E Mutation Impaired protein maturation 130-132 G91R Mutation Impaired protein maturation 130-132 N1303K Mutation Impaired protein maturation 130-132 ABCC8 WT Wild type Ubiquitin-proteasome degradation 133 A116P Mutation Ubiquitin-proteasome degradation 133 V187D Mutation Ubiquitin-proteasome degradation 133 F1388 Mutation Impaired protein trafficking 134 L1544P Mutation Impaired protein trafficking 135,136 ABCC11a G180R SNP Ubiquitin-proteasome degradation 50 27 Mutation Ubiquitin-proteasome degradation 50 ABCG2a V12M SNP Altered protein localization 96 Q141K SNP Ubiquitin-proteasome degradation 102 F208S SNP Ubiquitin-proteasome degradation 78,99 S441N SNP Ubiquitin-proteasome degradation 78,99 Mutations of ABCA1, ABCA3, ABCA4, ABCB4, ABCB11, ABCC2, ABCC7 (CFTR), and ABCC8 are associated with Tangier disease, fatal surfactant deficiency, Stargardt disease, progressive familial intrahepatic cholestasis type 3 (PFIC-3), progressive familial intrahepatic cholestasis type 2 (PFIC-2), Dubin-Johnson syndrome, cystic fibrosis, and familial hyperinsulinism, respectively. Login to comment

PMID: 21586796 [PubMed] Beers MF et al: "A novel conserved targeting motif found in ABCA transporters mediates trafficking to early post-Golgi compartments."

No. Sentence Comment

167 Most prominent of these was L101P, which, when transfected into similar cell lines, produced profound ER retention. Login to comment
193 However, like L101P, xLxxKN mutations would naturally affect functional outcome if the transporters were held from reaching their destined compartments. Login to comment
166 Most prominent of these was L101P, which, when transfected into similar cell lines, produced profound ER retention. Login to comment
192 However, like L101P, xLxxKN mutations would naturally affect functional outcome if the transporters were held from reaching their destined compartments. Login to comment

PMID: 15044640 [PubMed] Shulenin S et al: "ABCA3 gene mutations in newborns with fatal surfactant deficiency."

No. Sentence Comment

59 Seven missense muta- tionswereidentifiedinconservedaminoacids(Fig. 2), including homozygous substitutions of proline for leucine in codons 101 and 1553 (L101P and L1553P, respectively) and heterozygous substitutions of aspartic acid for asparagine at position 568 (N568D), proline for leucine at position 982 (L982P), serine for glycine at position 1221 (G1221S), proline for leucine at position 1580 (L1580P), and proline for glutamine at position 1591 (Q1591P). Login to comment
87 Human Mouse Rat Puffer fish ETVRRALVIN ETVKREFMIK EAVRREFMIK EDVRGKLELS QDVQQNLVRG L101P NGAGKTT NGAGKTT NGAGKTT NGAGKTT NGAGKTT N568D VARRLL VARRLL VARRLL VARRLL L1553P Q1591P T301C(L101P) C316T(R106X) A1702G(N568D) 1644delC G3426A(W1142X) G3661A(G1221S) T4657C(L1553P) 4552insT A4771C(Q1591P) 4909+1G>A G1221S LSGIAT LSGIAT LSGIAT ATP-binding domains L982P QQLSEHL QQLSENL QQLSEHL T2945C(L982P) ECEALC LAIMVQGQFKC ECEALC ECEALC L1580P T4739C(L1580P) Nonsense MissenseSpliceFrameshift LAIMVQGQFKC LAIMVQGQFKC LAVMVNGQFKC Zebra fish LAVMVNGQFKC tified occur in residues that are highly conserved (Fig.2).Theaminoacidalignmentwasusedtopro- duce a phylogenetic tree of the ABCA3-related proteins showing the relation of the proteins from different organisms (see Supplementary Appendix 2, available with the full text of this article at www. nejm.org).ThefishABCA3proteinsclusterwiththe mammalian ABCA3 proteins and are distinct from other, more distant ABCA-family proteins, such as the mouse Abca14, Abca15, and Abca16 proteins and the sea-urchin ABCA proteins (see Supplementary Appendix 2. Login to comment
97 In the case of the L101P and L1553P mutations, each of which affected one pair of siblings from two different families, the two pairs of siblings were both homozygous for the variant and homozygous for all other polymorphisms that we found in the gene - findings that are consistent with the occurrence of a recessive mutation in these consanguineous families. Login to comment
58 Seven missense muta- tionswereidentifiedinconservedaminoacids(Fig. 2), including homozygous substitutions of proline for leucine in codons 101 and 1553 (L101P and L1553P, respectively) and heterozygous substitutions of aspartic acid for asparagine at position 568 (N568D), proline for leucine at position 982 (L982P), serine for glycine at position 1221 (G1221S), proline for leucine at position 1580 (L1580P), and proline for glutamine at position 1591 (Q1591P). Login to comment
86 Human Mouse Rat Puffer fish ETVRRALVIN ETVKREFMIK EAVRREFMIK EDVRGKLELS QDVQQNLVRG L101P NGAGKTT NGAGKTT NGAGKTT NGAGKTT NGAGKTT N568D VARRLL VARRLL VARRLL VARRLL L1553P Q1591P T301C(L101P) C316T(R106X) A1702G(N568D) 1644delC G3426A(W1142X) G3661A(G1221S) T4657C(L1553P) 4552insT A4771C(Q1591P) 4909+1G>A G1221S LSGIAT LSGIAT LSGIAT ATP-binding domains L982P QQLSEHL QQLSENL QQLSEHL T2945C(L982P) ECEALC LAIMVQGQFKC ECEALC ECEALC L1580P T4739C(L1580P) Nonsense Missense Splice Frameshift LAIMVQGQFKC LAIMVQGQFKC LAVMVNGQFKC Zebra fish LAVMVNGQFKC tified occur in residues that are highly conserved (Fig.2).Theaminoacidalignmentwasusedtopro- duce a phylogenetic tree of the ABCA3-related proteins showing the relation of the proteins from different organisms (see Supplementary Appendix 2, available with the full text of this article at www. nejm.org).ThefishABCA3proteinsclusterwiththe mammalian ABCA3 proteins and are distinct from other, more distant ABCA-family proteins, such as the mouse Abca14, Abca15, and Abca16 proteins and the sea-urchin ABCA proteins (see Supplementary Appendix 2. Login to comment
96 In the case of the L101P and L1553P mutations, each of which affected one pair of siblings from two different families, the two pairs of siblings were both homozygous for the variant and homozygous for all other polymorphisms that we found in the gene - findings that are consistent with the occurrence of a recessive mutation in these consanguineous families. Login to comment

PMID: 22866751 [PubMed] Baekvad-Hansen M et al: "Heterozygosity for E292V in ABCA3, lung function and COPD in 64,000 individuals."

No. Sentence Comment

146 This is an important finding as 1.3 % in the Danish general population has partially reduced ABCA3 function due to E292V, and since this variant has been linked previously with severe chronic lung disease in heterozygous and compound heterozygous E292V carriers [8-10]. Login to comment
153 Another mutation in this loop, L101P, has been shown to affect ABCA3 protein folding leading to retention of ABCA3 in the endoplasmatic reticulum and subsequent ER stress and apoptosis [27,28], however individuals heterozygous for the H86Y mutation appeared asymptomatic in this study. Login to comment

PMID: 21214890 [PubMed] Weichert N et al: "Some ABCA3 mutations elevate ER stress and initiate apoptosis of lung epithelial cells."

No. Sentence Comment

4 Methods: Human alveolar epithelial A549 cells were transfected with vectors expressing wild-type ABCA3 or one of the three ABCA3 mutant forms, R43L, R280C and L101P, C-terminally tagged with YFP or hemagglutinin-tag. Login to comment
8 Results: We demonstrate that two ABCA3 mutations, which affect ABCA3 protein trafficking/folding and lead to partial (R280C) or complete (L101P) retention of ABCA3 in the ER compartment, can elevate ER stress and susceptibility to it and induce apoptotic markers in the cultured lung epithelial A549 cells. Login to comment
35 Fibrosis is one of the hallmarks documented in ABCA3-associated ILD [12,16,17] and knowing that ABCA3 mutations can cause ER retention of the mutated transporter [6,20], we investigated the influence of three ABCA3 mutations, R43L, R280C and L101P, found in children with surfactant deficiency and chronic ILD [10,14,19], on ER stress and apoptosis induction in lung epithelial A549 cells. Login to comment
39 Three hABCA3 point mutations R43L, R280C and L101P were introduced in the WT ABCA3 in both vector types by PCR-based site-directed mutagenesis (QuickChange Site-Directed Mutagenesis, Stratagene, La Jolla, CA). Login to comment
40 Mutagenesis primers were as follows: R43L-For 5`-CAT CTG GCT CCTCTT GAA GAT TC-3`, R43L-Rev 5`-GAA TCT TCA AGAGGA GCC AGA TG-3`, L101P-For 5`-CAG TGC GCA GGG CAC CTG TGA TCA AC-3`, L101P-Rev 5`- GTT GAT CAC AGG TGC CCT GCG CAC TG-3`, R280C-For 5`-CAT TGC CTG TGC TGT CGT G-3`, R280C-Rev 5`-CAC GAC AGC ACAGGC AAT G-3`. Login to comment
82 Results General characterization of R43L, R280C and L101P ABCA3 mutations A) Localization and trafficking Three clinically relevant ABCA3 mutations identified in patients with neonatal surfactant deficiency (R43L and L101P) and chronic ILD (R280C) were chosen for the study. Login to comment
83 While cell biology of R43L and R280C mutations has not been studied yet, L101P mutation was previously described as a trafficking/folding defect resulting in the ER accumulation of L101P protein [6,20] and was deliberately chosen for this study as a cause for the ABCA3 ER retention. Login to comment
84 Initially we investigated intracellular localization of the WT and R43L, R280C and L101P transporters. Login to comment
92 L101P mutation did not show any vesicular signal at all (Figure 1A) but presented with a cytoplasmic fluorescence mainly colocalizing with the ER protein calnexin (Figure 1B). Login to comment
93 This suggests correct localization of the WT and R43L transporters in the LAMP3-positive (LAMP3+ ) vesicles and almost full retention of the L101P mutant in the ER, possibly as a result of protein misfolding. Login to comment
97 The processing of ER retained L101P protein was different, showing complete lack of the 180 kDa band, in line with published data (Figure 2A) [6,20]. Login to comment
99 Processing of oligosaccharides and protein progress down the ER-Golgi maturation pathway Figure 1 Intracellular localization of the WT and mutant R43L, R280C and L101P ABCA3 proteins. Login to comment
101 YFP fluorescence of ABCA3-YFP fusions (green) was used to detect ABCA3 WT and R43L, R280C and L101P proteins. Login to comment
103 WT and R43L localized in LAMP3+ vesicles, R280C partially in LAMP3+ vesicles and partially in the ER and L101P completely in the ER. Login to comment
106 Immunoblotting with anti-GFP antibody revealed absence of complex sugars in L101P protein that was susceptible to both enzymes, PNGaseF and EndoH, resulting in both cases in a single shifted deglycosylated 210 kDa band and no 220 kDa band. Login to comment
109 This confirms the localization studies showing retention of the L101P mutant in the ER and ability of WT, R43L and R280C to progress further from the ER to the Golgi. Login to comment
110 C) Functional assay Trafficking/folding defect and ER accumulation of L101P protein exclude the ABCA3 function in the case of this mutant. Login to comment
113 Liposomes containing NBD-labeled major surfactant phospholipid phosphatidyl-choline (C12-NBD-PC) and NBD-labeled minor surfactant phospholipid phosphatidylethanol-amine (C12-NBD-PE) were incubated with A549 cells expressing WT, R43L, R280C and L101P HA-tagged proteins. Login to comment
114 L101P mutant was used to monitor the situation with nonfunctional ABCA3 protein. Login to comment
116 Interestingly, uptake of fluorescent liposomes into A549 cells was prominent in all cells, including those expressing L101P mutants (Figure 3) and therefore Figure 2 Processing of the WT and mutant R43L, R280C and L101P ABCA3. Login to comment
117 (A) Immunodetection with anti-GFP antibody showed two ABCA3 protein bands (180 kDa and 220 kDa) in whole cell lysates of A549 cells expressing WT and R43L and R280C mutations, and only one protein band in the cells expressing L101P mutation. Login to comment
118 (B) Deglycosylation assay with PNGaseF and EndoH on the membrane fractions from A549 cells transfected with pEYFP-N1/ ABCA3 plasmids and subsequent ABCA3-YFP immunodetection with anti-GFP antibody showed presence of high-mannose and complex oligosaccharides in WT, R43L and R280C proteins, as well as only high-mannose and no complex oligosaccharides in the L101P mutant resulting from the L101P ER retention. Login to comment
122 HA-tag was used to detect ABCA3 WT and R43L, R280C and L101P by immunofluorescence (red). Login to comment
125 Uptake through the plasma membrane into the cytoplasm of L101P transfected cells with no functional exogenous ABCA3 was observed as well as numerous cytoplasmic NBD-positive liposome-like vesicles in all A549 cells independent of the ABCA3 mutation shown in (A) and (B). Login to comment
127 WT ABCA3 (green) induced biogenesis of LAMP3+ vesicles (red) increasing their number and size in A549 cells, while R43L, R280C and L101P proteins showed no such effect (the same was observed in A549 pEYFP-N1/ABCA3 transfected cells - not shown). Login to comment
137 Expression of R43L, R280C and L101P mutations had a negative effect on vesicle formation and induced a lower number of smaller compact LAMP3+ vesicles, with the most drastic effect in L101P mutant (Figure 3D). Login to comment
140 L101P and R280C mutation upregulate ER stress marker BiP BiP/Grp78 is an essential ER chaperone of the Hsp70 family, which assists the translocation of a nascent protein chain into the ER and its subsequent folding. Login to comment
142 Immunoblotting of whole cell lysates from A549 cells expressing ABCA3-WT and three mutants revealed significant upregulation of BiP chaperone in the case of L101P mutation and R280C mutation in comparison to WT, caused by complete (L101P) or partial ER retention (R280C) of these two mutated ABCA3 transporters (Figure 4A, B). Login to comment
145 L101P and R280C mutations increase susceptibility of A549 cells to ER stress Upon ER accumulation of misfolded proteins BiP dissociates from the luminal domain of IRE1, allows IRE1 dimerization and synthesis of active XBP1 protein, a UPR transcription factor which regulates expression of ER stress proteins including BiP. Login to comment
147 To confirm previous observation on Figure 4 Increase in the ER stress chaperone BiP in A549 cells expressing R280C and L101P mutations. Login to comment
148 (A) A549 cells with ER retained L101P mutant or partially ER retained R280C protein showed upregulation of the immunodetected ER chaperone BiP in comparison to WT and A549 cells. Login to comment
155 In A549 cells with either WT or one of the three mutations, increase of XBP1 splicing was measured only in the case of L101P mutation (Figure 5D). Login to comment
156 Probably because of the robustness of the method, finer differences between WT and R43L and R280C were not observable, and the effect was measurable only in the case of the L101P mutant with the strongest protein defect (Figure 5A, D). Login to comment
161 (A) XBP1 splicing in untransfected A549 cells with and without tunicamycin (TM) treatment (10 μg/ml, 14 h) and in A549 cells with R43L, R280C and L101P mutations. Login to comment
168 Lower effect of L101P mutation on XBP1 splicing in A549 cells and no effect in A549 with WT and R43L and R280C mutations were observed. Login to comment
169 (B, E) TM treatment (10 μg/ml, 14 h) strongly induced XBP1 splicing (disappearance of unspliced bands u1 and u2) in all A549 cells expressing ABCA3 mutations, with the most significant increase in A549 expressing R280C and L101P mutations (increase in spliced band s). Login to comment
172 However, after exposure to tunicamycin XBP1 splicing was considerably more pronounced in R280C and L101P mutations if compared to A549 cells with WT and R43L mutations (Figure 5B, E). Login to comment
173 Obviously, although XBP1 splicing was measurable only for the strongest L101P defect under non-stimulated condition, cells with L101P and R280C mutations were significantly more prone to further elevation of ER stress upon exposure to an external stressor. Login to comment
174 L101P and to a lesser extent R280C mutation induce apoptosis of A549 cells Since prolonged ER stress can activate apoptosis, we analyzed if ABCA3 mutations can induce early and late apoptotic markers in A549 cells. Login to comment
178 Flow cytometry assay of Cy5-coupled Annexin V surface binding showed an increase in the number of annexin V+ /PI- cells in transfected YFP+ cells in the case of R280C and L101P mutations when compared to WT and R43L indicating an early apoptotic state of those cells (Figure 6A). Login to comment
181 Intracellular GSH level, measured by flow cytometry of monochlorobimane binding to GSH and generation of a fluorescent adduct, was decreased in the YFP+ cells with L101P protein compared to YFP+ WT, R43L and also compared to R280C (Figure 6B). Login to comment
185 Via flow cytometry assay of intracellular active caspase 3 we found an increase in caspase 3 activation in cells expressing ER retained L101P mutant in comparison to the WT and R43L cells (Figure 6C). Login to comment
186 Figure 6 Apoptosis in A549 cells expressing L101P and R280 mutations. Login to comment
188 Elevated early and late apoptotic markers were detectable in cells expressing L101P mutation, and one early marker (Annexin V) in cells expressing R280C mutation. Login to comment
190 In summary, while R43L mutation did not raise apoptotic signaling above the A549 or WT level, R280C mutation increased one early apoptotic marker and ER-localized L101P mutations significantly elevated early and late apoptotic markers, indicating injury of the cells with L101P protein. Login to comment
191 Prolonged ER stress leads to apoptosis through caspase 4 activation in cells expressing R280C and L101P mutations To examine if initiation of apoptosis in cells with ABCA3 mutations is indeed a consequence of the ER stress signaling, we assessed activation of caspase 4, which is activated by apoptotic stimuli that cause ER stress, but not other apoptotic stimuli [28,37]. Login to comment
195 Immunoblotting of whole cell lysates from the cells expressing WT or R43L, R280C or L101P mutations showed insignificant changes in pro-caspase 4 level between WT and mutations, but the level of pro-caspase 4 was somewhat higher in transfected cells then in A549 (Figure 7B). Login to comment
196 In contrast, cleaved caspase 4 in R280C and L101P mutants increased significantly in comparison to WT. Login to comment
198 This shows that caspase 4 is involved in apoptotic signaling in cells with L101P and R280C mutations and that activation of the apoptotic pathway can be a consequence of the ER stress caused by complete or partial ER retention of the ABCA3 protein. Login to comment
201 In this study we investigated the influence of three ABCA3 mutations, R43L, R280C and L101P, on intracellular stress and induction of apoptosis in cultured lung epithelial A549 cells. Login to comment
202 All three mutations were found in children with ABCA3-associated lung disease being either fatal neonatal respiratory distress syndrome (L101P and R43L [10,14]) or chronic ILD (R280C; own unpublished data, [19]). Login to comment
203 While cell biology of R43L and R280C mutations was studied here for the first time, L101P mutation was used as a known example of the trafficking/folding defect leading to the ER retention of ABCA3 with no information on ER stress [6,20]. Login to comment
205 We showed correct localization of WT and R43L proteins in LAMP3+ vesicles and dual localization of R280C protein in LAMP3+ vesicles Figure 7 Apoptotic signaling in cells with L101P and R280C mutations is activated by ER stress. Login to comment
206 (A) Immunoblotting on whole cell lysates from A549 cells transfected with pEYFP-N1/ABCA3 and densitometric analyses of (B) pro-caspase 4 and (C) cleaved caspase 4 demonstrated increased caspase 4 cleavage in cells expressing L101P and R280C mutations, as well as after TNFa treatment of A549 (25 ng/ml, 16 h) in comparison to WT and untreated A549. Login to comment
207 No significant changes in the pro-caspase 4 level in transfected cells with WT, R43L, R280C and L101P mutations were detected but pro-caspase 4 was slightly increased in transfected cells compared to A549 (B). Login to comment
213 L101P protein remained in the ER, having therefore no complex sugars, and no smaller 180 kDa protein form (Figure 1B and 2A, B) [6,20]. Login to comment
214 While ER retention of L101P excludes ABCA3 function, the function of R43L and R280C transporters was studied additionally. Login to comment
217 In contrast to the WT, expression of ABCA3 mutations, especially L101P, impaired biogenesis of LAMP3+ vesicles by reducing their number and size (Figure 3D). Login to comment
223 The uptake and number of NBD-vesicles observed in the cytoplasm was similar for both phospholipids in A549 cells and in transfected A549, and was also independent of the ABCA3 mutation, including L101P. Login to comment
230 L101P protein which accumulates in the ER, caused significant increase of the ER stress and early and late apoptosis markers in the A549 cells (Figure 4, 5 and 6). Login to comment
233 The connection between ER stress and apoptosis induction was established through the upregulation of caspase 4 in the case of both L101P and R280C mutations (Figure 7). Login to comment
237 The cells with mutations R280C and L101P, which impair ABCA3 trafficking, were more prone to further XBP1 splicing than the WT or A549. Login to comment

PMID: 20863830 [PubMed] Engelbrecht S et al: "The surfactant lipid transporter ABCA3 is N-terminally cleaved inside LAMP3-positive vesicles."

No. Sentence Comment

134 complete absence of the lower band we noticed only in the case of Q215K and other ER retained ABCA3 mutations (e.g. L101P; own data, [8,9]). Login to comment

PMID: 19861431 [PubMed] Park SK et al: "Identification and characterization of a novel ABCA3 mutation."

No. Sentence Comment

53 Transient transfections of HEK293 cells with wild-type ABCA3-GFP and ABCA3 mutants L101P-GFP, N568D-GFP, and L982P-GFP (14), as well as the new pEGFPN1 construct for R295C-GFP, were performed with FuGENE 6 transfection reagent (Roche Applied Science, Indianapolis, IN) as previously described (14). Login to comment
99 Type I mutations include L101P, L982P, L1553P, and Q1591P; type II mutations include E292V, N568D, E690K, T1114, G1221S, and L1580P (13, 14). Login to comment
100 B: alignment of sequences surrounding the R295C mutation in ICL-1 in various members of the ABCA subfamily. Login to comment
105 As reported previously, the N568D variant shows resistance to Endo H (Fig. 3A, lanes 8 and 9) at a level similar to that of the wild-type protein; however, the L101P and L982P variants (Fig. 3A, lanes 4 and 5 and lanes 10 and 11, respectively) show no Endo H resistance, indicating that these mutants have not left the endoplasmic reticulum (14). Login to comment
126 A: 20 ␮g of membrane fraction from HEK293 cells transiently transfected with WT ABCA3-GFP (lanes 2 and 3) or with ABCA3-GFP mutants L101P (lanes 4 and 5), R295C (lanes 6 and 7), N568D (lanes 8 and 9), and L982P (lanes 10 and 11) were treated without (-) or with (ϩ) endoglycosidase H (Endo H) and analyzed by 5% SDS-PAGE followed by immunoblotting with anti-GFP antibody. Lane 1, immunoblotting of untransfected HEK293 cells. Login to comment
127 B: WT ABCA3-GFP (lanes 2 and 3) or ABCA3-GFP mutants L101P (lanes 4 and 5), R295C (lanes 6 and 7), N568D (lanes 8 and 9), and L982P (lanes 10 and 11) were treated without (-) or with (ϩ) peptide N-glycosidase F (PNGase F) and were then analyzed by 5% SDS-PAGE followed by immunoblotting with anti-GFP antibody. Lane 1, immunoblotting of untransfected HEK293 cells. Login to comment
48 Transient transfections of HEK293 cells with wild-type ABCA3-GFP and ABCA3 mutants L101P-GFP, N568D-GFP, and L982P-GFP (14), as well as the new pEGFPN1 construct for R295C-GFP, were performed with FuGENE 6 transfection reagent (Roche Applied Science, Indianapolis, IN) as previously described (14). Login to comment
94 Type I mutations include L101P, L982P, L1553P, and Q1591P; type II mutations include E292V, N568D, E690K, T1114, G1221S, and L1580P (13, 14). Login to comment
122 A: 20 òe;g of membrane fraction from HEK293 cells transiently transfected with WT ABCA3-GFP (lanes 2 and 3) or with ABCA3-GFP mutants L101P (lanes 4 and 5), R295C (lanes 6 and 7), N568D (lanes 8 and 9), and L982P (lanes 10 and 11) were treated without (afa;) or with (af9;) endoglycosidase H (Endo H) and analyzed by 5% SDS-PAGE followed by immunoblotting with anti-GFP antibody. Lane 1, immunoblotting of untransfected HEK293 cells. Login to comment
123 B: WT ABCA3-GFP (lanes 2 and 3) or ABCA3-GFP mutants L101P (lanes 4 and 5), R295C (lanes 6 and 7), N568D (lanes 8 and 9), and L982P (lanes 10 and 11) were treated without (afa;) or with (af9;) peptide N-glycosidase F (PNGase F) and were then analyzed by 5% SDS-PAGE followed by immunoblotting with anti-GFP antibody. Lane 1, immunoblotting of untransfected HEK293 cells. Login to comment

PMID: 18676873 [PubMed] Matsumura Y et al: "Aberrant catalytic cycle and impaired lipid transport into intracellular vesicles in ABCA3 mutants associated with nonfatal pediatric interstitial lung disease."

No. Sentence Comment

89 We previously found that GFP-tagged wild-type ABCA3 protein (ABCA3-GFP) expressed in cultured cells is localized mainly at the limiting membrane of LAMP3-positive vesicles, whereas type I mutant protein (e.g., L101P) in fatal surfactant deficiency remains localized in the endoplasmic reticulum, accompanied by impaired processing of oligosaccharide (17). Login to comment
230 Although E292V, E690K, and T1114M mutant proteins were found to traffic to intracellular vesicles, the lipid transport function of E292V mutant protein was partially impaired, and those of E690K and T1114M mutant protein were severely impaired, accompanied by an aberrant catalytic cycle. Login to comment
233 Patients with fatal surfactant deficiency carrying a type I homozygous ABCA3 mutation (W1142X/W1142X, L101P/ L101P, or L1553P/L1553P) or a type I/type II compound heterozygous mutation (L982P/G1221S or Ins1518/L1580P) die within the neonatal period (Table 1) (27). Login to comment
252 Genotype-phenotype correlation for ABCA3 mutation ABCA3 Mutation Age of Symptoms Phenotype Ref. W1142X W1142X Neonate FSD 27 L101P L101P Neonate FSD 27 L1553P L1553P Neonate FSD 27 Ins1518 L1580P Neonate FSD 27 L982P G1221S Neonate FSD 27 E292V T1114M Neonate pILD 4 E292V E690K 5 or 7 yr pILD 4 W1148X T1114A 12 mo pILD 37 Type I and type II ATP binding cassette A3 (ABCA3) mutations are shown in italics and roman, respectively. Login to comment
85 We previously found that GFP-tagged wild-type ABCA3 protein (ABCA3-GFP) expressed in cultured cells is localized mainly at the limiting membrane of LAMP3-positive vesicles, whereas type I mutant protein (e.g., L101P) in fatal surfactant deficiency remains localized in the endoplasmic reticulum, accompanied by impaired processing of oligosaccharide (17). Login to comment
249 Genotype-phenotype correlation for ABCA3 mutation ABCA3 Mutation Age of Symptoms Phenotype Ref. W1142X W1142X Neonate FSD 27 L101P L101P Neonate FSD 27 L1553P L1553P Neonate FSD 27 Ins1518 L1580P Neonate FSD 27 L982P G1221S Neonate FSD 27 E292V T1114M Neonate pILD 4 E292V E690K 5 or 7 yr pILD 4 W1148X T1114A 12 mo pILD 37 Type I and type II ATP binding cassette A3 (ABCA3) mutations are shown in italics and roman, respectively. Login to comment

PMID: 18246475 [PubMed] Karjalainen MK et al: "Haplotype analysis of ABCA3: association with respiratory distress in very premature infants."

No. Sentence Comment

90 SNP rs149532 (corresponding to residue S1372S) was rare (MAF50.02) in our population, and it was thus excluded from further analysis, together with the nonpolymorphic cSNPs (rs28936412, 875AwT, rs13332760, rs28936690, and rs28936691, corresponding to residues L101P, E292V, V839F, L1552P, and Q1591P, respectively). Login to comment
94 SNP No. or position a Alleles (major/minor) Position b Location Affected residue Minor allele frequency tSNPs c Best pairwise r2 value and the corresponding tSNP d rs28936412 T/C 2316029 Exon 5 L101P 0 - 320-17GwA G/A 2314550 Intron 5 0.055 tSNP1 875AwT A/T 2307765 Exon 9 E292V 0 - rs13332547 C/T 2307425 Intron 9 0.093 tSNP2, r2 51 rs13332514 C/T 2307337 Exon 10 F353F 0.093 tSNP2 rs323069 G/C 2304052 Intron 10 0.271 tSNP3 rs323073 C/T 2298761 Intron 10 0.283 tSNP3, r2 50.831 rs323074 G/A 2298314 Intron 11 0.201 tSNP5, r2 50.848 rs323033 A/G 2296546 Intron 11 0.259 tSNP4 rs323040 G/A 2290527 Intron 12 0.168 tSNP5 rs170447 A/G 2289372 Intron 14 0.396 tSNP6, r2 50.832 rs2240523 T/C 2288658 Intron 14 0.381 tSNP6, r2 50.849 rs17183533 A/G 2285389 Intron 18 0.420 tSNP7, r2 50.986 rs13332760 G/T 2279621 Exon 20 V839F 0 - rs313909 C/T 2277994 Intron 21 0.373 tSNP6 rs2014467 A/G 2276395 Intron 22 0.424 tSNP7 rs2238464 G/A 2272578 Intron 26 0.420 tSNP8 rs149532 T/C 2271431 Exon 27 S1372S 0.020 - rs150926 G/C 2270170 Intron 28 0.372 tSNP6, r2 50.975 rs150928 C/T 2268651 Intron 29 0.226 tSNP9 rs28936690 T/C 2268353 Exon 30 L1552P 0 - rs28936691 A/C 2268018 Exon 31 Q1591P 0 - a rs numbers are shown for SNPs with entries in dbSNP. SNPs without entries in dbSNP are numbered from start codon as advised in (34). Login to comment
212 Of these, two (corresponding to L101P and Q1591P) have been previously identified in term infants with fatal surfactant deficiency or chronic lung disease (13). Login to comment

PMID: 16959783 [PubMed] Matsumura Y et al: "Characterization and classification of ATP-binding cassette transporter ABCA3 mutants in fatal surfactant deficiency."

No. Sentence Comment

3 Green fluorescent protein-tagged L101P, L982P, L1553P, Q1591P, and Ins1518fs/ter1519 mutant proteins remained localized in the endoplasmic reticulum, and processing of oligosaccharide was impaired, whereas wild-type and N568D, G1221S, and L1580P mutant ABCA3 proteins trafficked to the LAMP3-positive intracellular vesicle, accompanied by processing of oligosaccharide from high mannose type to complex type. Login to comment
35 Partial cDNA fragments containing various fatal surfactant deficiency mutations (L101P, N568D, L982P, G1221S, L1553P, L1580P, Q1591P, W1142X, and Ins1518fs (abbreviation of Ins1518fs/ter1519 in this study), see Fig. 1A), were generated with PCR methods and replaced with the corresponding fragment of pEGFPN1-ABCA3. Login to comment
98 To examine the effect of the mutations found in fatal surfactant deficiency patients on subcellular localization of ABCA3, wild-type and mutant ABCA3-GFP (seven missense mutations L101P, N568D, L982P, G1221S, L1553P, L1580P, and Q1591P, and one nonsense mutation, Ins1518fs) were transiently expressed in HEK293 cells (Fig. 1A). Login to comment
100 In contrast, the L101P, L982P, L1553P, Q1591P, and Ins1518fs mutant proteins were barely detectable at the LAMP3-positive intracellular vesicle membrane (Fig. 2B panels j-l for L101P and data not shown for others). Login to comment
102 In another cell line, mouse lung epithelial MLE12 cells, transiently expressed GFP-tagged wild-type and N568D, G1221S, and L1580P mutant proteins were mainly localized at the intracellular vesicle membrane, whereas the L101P, L982P, L1553P, Q1591P, and Ins1518fs mutant proteins were mainly localized to the ER (data not shown), confirming defective intracellular sorting of L101P, L982P, L1553P, Q1591P, and Ins1518fs ABCA3 mutant proteins. Login to comment
106 In contrast, in the L101P, L982P, L1553P, and Q1591P mutant proteins, which were mainly localized at the ER, the amount of the 180-kDa cleaved form was considerably decreased, compared with that of wild-type protein, to an undetectable level (Fig. 3A). Login to comment
121 A merged image of panels i-k is shown in panel l. B, HEK293 cells transiently expressing mutant ABCA3-GFP proteins (panels a, d, g, and j) were processed for immunofluorescence labeling of LAMP3 (panels b, e, h, and k): N568D (panels a-c), G1221S (panels d-f), L1580P (panels g-i), and L101P (panels j-l). Login to comment
122 Merged images are shown in panels c, f, i, and l. C, HEK293 cells transiently co-expressing mutant ABCA3-GFP proteins (panels a, d, g, j, and m) and DsRed2-ER (panels b, e, h, k, and n) are shown: L101P (panels a-c), L982P (panels d-f), L1553P (panels g-i), Q1591P (panels j-l), and Ins1518fs (panels m-o). Login to comment
124 The scale bar represents 5 ␮m. kDa wild-type ABCA3-GFP and the seven missense mutant (L101P, N568D, L982P, G1221S, L1553P, L1580P, and Q1591P) proteins to produce a 210-kDa deglycosylated protein (Fig. 3B). Login to comment
129 However, in the L101P, L982P, L1553P, Q1591P, and Ins1518fs mutant proteins, the levels of complex-type protein (band I) were dramatically decreased compared with that of wild-type protein (Fig. 3, C and D). Login to comment
131 These results indicate that the N568D, G1221S, and L1580P mutant proteins are mainly localized at the intracellular vesicle membrane accompanied by processing of oligosaccharide from high mannose type to complex type, whereas the four missense mutant (L101P, L982D, L1553P, and Q1591P) and one nonsense mutant (Ins1518fs) proteins remain localized at the ER, with impaired processing of oligosaccharide. Login to comment
154 To examine ATP hydrolysis of the mutant retained to the ER, cells stably expressing L101P mutant protein were established. Login to comment
155 L101P mutant protein was mainly localized to the ER, consistent with the result in transiently expressing cells (data not shown). Login to comment
156 The vanadate-induced nucleotide trapping also was significantly decreased compared with that of wild-type protein (Fig. 4B, lanes 3 and 4), indicating that ATP hydrolysis activity as well as intracellular trafficking is impaired in the L101P mutant protein. Login to comment
164 B, 20,000 ϫ g membrane fraction prepared from HEK293 cells stably expressing the wild-type (Wt) ABCA3-GFP (lanes 1 and 2) or L101P (lanes 3 and 4) was similarly analyzed. Login to comment
170 A, 20,000 ϫ g membrane fraction prepared from HEK293 cells stably expressing wild-type (Wt) ABCA3-GFP, N568D, G1221S, L101P, or untransfected HEK293 cells was incubated with 20 ␮M 8-azido-[␥-32 P]ATP and 3 mM MgCl2 for 10 min at 0 °C. Proteins were photoaffinity-labeled with UV irradiation, immunoprecipitated using anti-human ABCA3 antibody, electrophoresed on SDS-PAGE (5%), and transferred to a PVDF membrane. Login to comment
176 The level of photoaffinity labeling of L101P protein remaining localized at the ER was considerably decreased to 25% that of wild-type protein. Login to comment
177 These results suggest that decreased ATP binding contributes to impaired ATP hydrolysis in the N568D, L1580P, and L101P mutants but not in the G1221S mutant. Login to comment
216 Investigating the intracellular localization and N-glycosylation of these ABCA3 mutant proteins in HEK293 cells, we found the missense L101P, L982P, L1553P, Q1591P, and nonsense Ins1518fs mutant proteins to be predominantly localized at the ER, with impaired processing of oligosaccharide. Login to comment
221 Interestingly, a single amino acid is substituted with a proline residue in the four mutant ABCA3 proteins (L101P, L982P, L1553P, and Q1591P) that are retained at the ER. Login to comment
222 As three of these mutations (L101P, L982P, and L1553P) are located in the predicted ␣-helical structure of the ABCA3 protein (32) and the proline residue is known to be helix breaker (39), its introduction into the ABCA3 protein might well disrupt the ␣-helical structure and hamper proper folding and intracellular translocation. Login to comment
223 The large C-terminal deletion of the ABCA3 protein (Ins1518fs and W1142X) also might hamper this process. Login to comment
224 Indeed, patients with homozygous mutations of L101P, L1553P, and W1142X have been reported to die of surfactant deficiency during the neonatal period, and electron microscopic study of lung tissue from patients with homozygous L1553P and W1142X mutations revealed smaller lamellar bodies than those in normal lung tissue (12). Login to comment
266 We examined ATP binding and ATP hydrolysis of the type I mutant ABCA3 protein by using cells stably expressing L101P mutant protein, and we found that both ATP binding and ATP hydrolysis activities as well as intracellular trafficking were impaired in the L101P mutant protein. Login to comment
271 It is possible that the E292V mutation causes less severe disruption of intracellular trafficking or ATP hydrolysis activity. Login to comment
273 Very recently, Cheong et al. (19) reported that L101P, G1221S, and N568D mutant proteins have the most severe, moderate, and the least severe trafficking and processing defects. Login to comment
215 Investigating the intracellular localization and N-glycosylation of these ABCA3 mutant proteins in HEK293 cells, we found the missense L101P, L982P, L1553P, Q1591P, and nonsense Ins1518fs mutant proteins to be predominantly localized at the ER, with impaired processing of oligosaccharide. Login to comment
220 Interestingly, a single amino acid is substituted with a proline residue in the four mutant ABCA3 proteins (L101P, L982P, L1553P, and Q1591P) that are retained at the ER. Login to comment
264 We examined ATP binding and ATP hydrolysis of the type I mutant ABCA3 protein by using cells stably expressing L101P mutant protein, and we found that both ATP binding and ATP hydrolysis activities as well as intracellular trafficking were impaired in the L101P mutant protein. Login to comment

PMID: 16415354 [PubMed] Cheong N et al: "Functional and trafficking defects in ATP binding cassette A3 mutants associated with respiratory distress syndrome."

No. Sentence Comment

43 hABCA3 missense mutants (L101P, N568D, and G1221S) were generated using the PCR method with the following primers: L101P (forward primer, 5Ј-AGACAGTGCGCAGGGCACCTGTGATCAACATGCG- AG-3Ј; reverse primer, 5Ј-CTCGCATGTTGATCACAGGTGCCCT- GCGCACTGTCT-3Ј); N568D (forward primer, 5Ј-ATCACCGTCCT- GCTGGGCCACGACGGTGCCGGGAAGAC-3Ј; reverse primer, 5Ј- GTCTTCCCGGCACCGTCGTGGCCCAGCAGGACGGTGAT-3Ј); and G1221S (forward primer, 5Ј-ATCTTCAACATCCTGTCAGCCA- TCGCCACCTTCCTG-3Ј; reverse primer, 5Ј-CAGGAAGGTGGCG- AGGCCTGACAGGATGTTGAAGAT-3Ј), where the mutated nucleotides are underlined. Login to comment
46 hABCA3-GFP/HEK293, GFP/HEK293, L101P-hABCA3-GFP/HEK293, and G1221S hABCA3-GFP/HEK293 stable cell lines were selected with 500 ␮g/ml G418 and maintained with 200 ␮g/ml G418 in growth medium. Login to comment
47 When L101P hABCA3-GFP/HEK293 and G1221S hABCA3-GFP/HEK293 cells were at 80% confluence, 1 mM 4-PBA was added and cells incubated for 24 h at 37 °C. Login to comment
96 The first was in extracellular loop 1 (L101P), the second in the Walker A motif or P-loop (phosphate binding loop) of the N-terminal nucleotide binding domain (N568D), and the third in transmembrane domain 11 (G1221S) of hABCA3. Login to comment
99 The construct containing mutation L101P of ABCA3-GFP failed to target the lysosomal membrane (Fig. 2A, d-f) and mainly remained in the ER (Fig. 2B, d-f)). Login to comment
103 Western blotting with GFP antibody revealed that mutant protein is expressed at a lower overall level than wild-type protein and that wild-type and mutant fusion proteins (L101P, N568D, and G1221S) are processed differently (Fig. 2C). Login to comment
106 Densitometry analysis of a 180/220-kDa ratio of Western blot (Fig. 2C) was 0.85 for the wild-type protein, 0.45 for the N568D mutant, 0.3 for the G1221S mutant, and essentially 0.0 for the L101P mutant. Login to comment
117 LysoTracker Red (A) and ERTracker Red (B) staining of wild-type (a-c) and missense mutations of hABCA3 (L101P (d-f), N568D (g-i), and G1221S (j-l)) linked to GFP in transfected A549 cells. Login to comment
119 The wild-type, L101P, N568D, and G1221S hABCA3-GFP membrane fractions were incubated in the absence (-) or presence (ϩ) of 250 units of PNGase F at 37 °C for 1 h. Login to comment
122 investigate whether trafficking of mutant hABCA3 could be restored, 4-PBA was applied to cells expressing the hABCA3-GFP missense mutants L101P hABCA3-GFP, and G1221S hABCA3-GFP and visualized by confocal microscopy. Login to comment
123 The addition of 1 mM 4-PBA to HEK239 cells stably transfected with G1221S hABCA3-GFP and L101P hABCA3-GFP markedly altered GFP localization from the ER to the membranes of punctate vesicles (Fig. 3, A and B, and supplemental Fig. 3), but it did not alter the localization of wild-type hABCA3-GFP (supplemental Fig. 4). Login to comment
124 Vesicles with G1221S hABCA3-GFP (Fig. 3B, b, d, and f)), but not L101P hABCA3-GFP (Fig. 3A, b, d, and f)), stained positively with LysoTracker Red. Login to comment
125 Western blots with GFP antibody showed that total hABCA3-GFP protein was increased in the presence of 4-PBA for both L101P and G1221S hABCA3-GFP (Fig. 3C) but that the ratio of 180/220 kDa protein bands increased only for the G1221S hABCA3-GFP mutant (Fig. 3D), providing further evidence that the lower molecular weight protein form correlates with lysosomal processing. Login to comment
139 4-PBA facilitates lysosomal targeting of G1221S-GFP but not L101P-GFP. Login to comment
140 A, 4-PBA treatment failed to restore L101P ABCA3-GFP trafficking to lysosomes. Login to comment
143 Western blots with anti-GFP (top) and anti beta-actin (bottom) antibodies of cell lysates from L101P and G1221S hABCA3-GFP cells in the absence (-) or presence (ϩ) of 1 mM 4-PBA treatment. Login to comment
192 The (L101P) mutant in extracellular loop 1 of ABCA3 had the most severe trafficking defect. Login to comment
223 Scale bars represent 10 ␮m. lowing 4-PBA treatment in the L101P mutant (Fig. 3A). Login to comment
116 LysoTracker Red (A) and ERTracker Red (B) staining of wild-type (a-c) and missense mutations of hABCA3 (L101P (d-f), N568D (g-i), and G1221S (j-l)) linked to GFP in transfected A549 cells. Login to comment
118 The wild-type, L101P, N568D, and G1221S hABCA3-GFP membrane fractions were incubated in the absence (afa;) or presence (af9;) of 250 units of PNGase F at 37 &#b0;C for 1 h. Login to comment
121 ABCA3 Role in Lipid Transport and Lamellar Body Biogenesis 9794 JOURNAL OF BIOLOGICAL CHEMISTRY VOLUME 281ߦNUMBER 14ߦAPRIL 7, 2006 investigate whether trafficking of mutant hABCA3 could be restored, 4-PBA was applied to cells expressing the hABCA3-GFP missense mutants L101P hABCA3-GFP, and G1221S hABCA3-GFP and visualized by confocal microscopy. Login to comment
138 4-PBA facilitates lysosomal targeting of G1221S-GFP but not L101P-GFP. Login to comment
142 Western blots with anti-GFP (top) and anti beta-actin (bottom) antibodies of cell lysates from L101P and G1221S hABCA3-GFP cells in the absence (afa;) or presence (af9;) of 1 mM 4-PBA treatment. Login to comment
191 The (L101P) mutant in extracellular loop 1 of ABCA3 had the most severe trafficking defect. Login to comment
221 Scale bars represent 10 òe;m. ABCA3 Role in Lipid Transport and Lamellar Body Biogenesis APRIL 7, 2006ߦVOLUME 281ߦNUMBER 14 JOURNAL OF BIOLOGICAL CHEMISTRY 9799 lowing 4-PBA treatment in the L101P mutant (Fig. 3A). Login to comment

PMID: 24142515 [PubMed] Beers MF et al: "Disruption of N-linked glycosylation promotes proteasomal degradation of the human ATP-binding cassette transporter ABCA3."

No. Sentence Comment

228 Firstly, expression of the leucine-to-proline mutation at residue 101 (L101P) results in ER-retained, unprocessed ABCA3 product that induces the unfolded proteins response and ER stress (10, 37, 56), suggesting that this mutation causes gross misfolding of ABCA3. Login to comment

PMID: 25406294 [PubMed] Chen P et al: "Mutations in the ABCA3 gene are associated with cataract-microcornea syndrome."

No. Sentence Comment

293 Genetic Variants Identified in ABCA3 in Patients With Surfactant Metabolism Dysfunction-3 (SMDP3) dbSNP rs# Cluster ID Codons Substitution Mutation Type Mutation Mode rs121909181 c.3426G>A W1142X Missense Homozygosity rs121909182 c.301T>C L101P Missense Homozygosity rs121909183 c.4657T>C L1553P Missense Homozygosity rs28936691 c.4772A>C Q1591P Missense Heterozygosity rs121909184 c.1702G>A N568D Missense Heterozygosity - c.4909&#fe;1G>A - Splice site Homozygosity rs121909185 c.977T>C L326P Missense Homozygosity 19. Login to comment

PMID: 26186947 [PubMed] Mulugeta S et al: "Lost after translation: insights from pulmonary surfactant for understanding the role of alveolar epithelial dysfunction and cellular quality control in fibrotic lung disease."

No. Sentence Comment

267 Summary of reported phenotypic features for surfactant component mutations Mutation (Domain) Clinical Diagnosis Lung Phenotype (in vivo) Subcellular Localization Trafficking Cellular Responses (in vitro) References SFTPA2 F198S (CRD) G231V (CRD) Familial pulmonary fibrosis Total BAL [SP-A] Normal ER retention Intracellular aggregation Not secreted (af9;) ER stress, cleared by ERAD (af9;) TGFbeta1 elaboration 99, 100, 175 SFTPC Group A1 èc;Exon4 (BRICHOS) L188Q (BRICHOS) G100S (BRICHOS) NSIP (Children) IPF/UIP (Adult) Absence of mature SP-C (humans) Arrested lung development (mice) ER stress (humans; mice) 1Sensitivity to bleomycin (mice) Epithelial cytotoxicity ER retention&#a1; aggresomes Intracellular aggregates ERAD requires Erdj 4/5 MG132 blocks degradation 4-PBA improves aggregates (af9;) ER stress (af9;) Apoptosis (af9;) Incomplete or absent proSP-C processing (af9;) IL-8/TGFbeta1 expression (af9;) Polyubiquitinated isoforms 21, 39, 97, 98, 100, 111, 112, 116, 117, 120, 153, 159, 160, 173, 193 Group A2 L110R (BRICHOS) P115L (BRICHOS) A116D (BRICHOS) Unspecified ILD Unspecified ILD Unspecified chILD Phenotype not reported EEA-1 (af9;); Syntaxin2 (afa;) Intracellular aggregation 2 PC secretion (af9;) Aberrant processing, 2 cell viability 1 HSP response (af9;) Congo red aggregates 160, 193 Group B1 E66K (Linker) I73T (Linker) NSIP/PAP (Child) IPF/UIP (Adult) 1 Phospholipid; 1SP-A, PAS positive staining Biopsy: PM and EE localization Misprocessed SP-C (BAL) Misprocessed SP-B (BAL) Plasma membrane&#a1;EE&#a1;LE/MVB (af9;) Aberrantly processed protein (af9;) Late autophagy block 2 Mitophagy 1 Mysfunctional mitochondria 1, 19, 24, 26, 49, 116, 118, 128, 152 Group B2 èc;91-93 (Non-BRICHOS) NSIP/PAP 2 BAL SP-B 1 BAL SP-A 2 Surfactant surface tension (af9;) Intracellular aggregates (af9;) Congo red staining Plasma membraneߥ EEA1 (af9;) compartmentsߥ Not reported 55, 181 Group C P30L (NH2-terminal) Unspecified ILD Phenotype not reported (af9;) ER retention 1 Bip expression (af9;) Polyubiquitinated isoforms 13, 116, 160 ABCA3 Group I (Trafficking Defective) L101P (1st luminal loop) R280C (1st cytosolic loop) L982P (3rd luminal loop) G1221S (11th TM domain) L1553P (COOH-terminal) Q1591P (COOH-terminal) Surfactant deficiency* RDS* chILDߤ Phenotype not reported Phenotype not reported Phenotype not reported (af9;) ER retention Non-LRO cytosolic vesicles (af9;) ER stress 30, 31, 103, 147, 172, 177 Group II (Functionally Defective) R43L (1st luminal loop) D253H (1st luminal loop) E292V (1st cytosolic loop) N568D (ABC1) E690K (ABC1) T1114M (8thTM domain) T1173R (1st luminal loop) L1580P (COOH-terminal) Surfactant deficiency* RDS* chILD (CPI)ߤ Reduced SP-B and SP-C (afa;) ER retention Lysosomes or LROs (normal) Impaired lipid transport Impaired ATP hydrolysis Impaired ATP binding Abnormal LBs 1 IL8 secretion 20, 25, 103, 104, 147, 148, 177 *Seen with homozygous or compound heterozygous ABCA3 expression; ߤfound with heterozugous ABCA3 expression. Login to comment
304 Although not restricted to any particular domain, functional characterization of a subgroup of ABCA3 mutations (including L101P, L982P, L1553P, Q1591P, G1221S) by transient or stable expression results in their total or partial retention in the ER (30, 103). Login to comment