ABCMdb

ABCA3 p.Thr1114Met

Predicted by SNAP2:	A: N (53%), C: D (53%), D: D (53%), E: N (57%), F: D (66%), G: D (59%), H: N (61%), I: D (53%), K: D (85%), L: D (59%), M: N (53%), N: N (61%), P: D (59%), Q: N (53%), R: N (53%), S: N (72%), V: N (53%), W: D (80%), Y: D (63%),
Predicted by PROVEAN:	A: N, C: D, D: N, E: N, F: D, G: N, H: D, I: D, K: N, L: D, M: D, N: N, P: N, Q: N, R: N, S: N, V: D, W: D, Y: D,

[switch to compact view]
Comments [show]

None has been submitted yet.

Publications
[hide] Identification and characterization of a novel ABC... Physiol Genomics. 2010 Jan 8;40(2):94-9. Epub 2009 Oct 27. Park SK, Amos L, Rao A, Quasney MW, Matsumura Y, Inagaki N, Dahmer MK
Identification and characterization of a novel ABCA3 mutation.
Physiol Genomics. 2010 Jan 8;40(2):94-9. Epub 2009 Oct 27., [PMID:19861431]

Abstract [show]
Mutations in the gene coding for ATP-binding cassette protein A3 (ABCA3) are recognized as a genetic cause of lung disease of varying severity. Characterization of a number of mutant ABCA3 proteins has demonstrated that the mutations generally affect intracellular localization or the ability of the protein to hydrolyze ATP. A novel heterozygous mutation that results in the substitution of cysteine for arginine at amino acid 295 in ABCA3 was identified in a premature infant with chronic respiratory insufficiency and abnormal lamellar bodies. Sequencing of DNA performed in study participants demonstrated that this was a mutation and not a common variant. Plasmid vectors containing ABCA3 with the identified novel mutation tagged with green fluorescent protein on the carboxy terminus were generated. The effect of the mutation on protein function was characterized by examining the glycosylation state of the mutant protein in transiently transfected HEK293 cells and by examining ATP hydrolysis activity of the mutant protein with a vanadate-induced nucleotide trapping assay in stably transfected HEK293 cells. The ABCA3 protein containing the R295C mutation undergoes normal glycosylation and intracellular localization but has dramatically reduced ATP hydrolysis activity (12% of wild type). The identification of one copy of this novel mutation in a premature infant with chronic respiratory insufficiency suggests that ABCA3 haploinsufficiency together with lung prematurity may result in more severe, or more prolonged, respiratory failure.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
110 The level of the ABCA3-R295C-GFP mutant protein was comparable to that of wild-type ABCA3-GFP as demonstrated in the anti-GFP immunoblot. Login to comment
115 Other mutations in the ABCA3 protein also result in impaired ATP hydrolysis, including E292V, N568D, G1221S, L1580P, and T1114M (13, 14). Login to comment

[hide] Aberrant catalytic cycle and impaired lipid transp... Am J Physiol Lung Cell Mol Physiol. 2008 Oct;295(4):L698-707. Epub 2008 Aug 1. Matsumura Y, Ban N, Inagaki N
Aberrant catalytic cycle and impaired lipid transport into intracellular vesicles in ABCA3 mutants associated with nonfatal pediatric interstitial lung disease.
Am J Physiol Lung Cell Mol Physiol. 2008 Oct;295(4):L698-707. Epub 2008 Aug 1., [PMID:18676873]

Abstract [show]
The ATP-binding cassette transporter ABCA3 mediates uptake of choline-phospholipids into intracellular vesicles and is essential for surfactant metabolism in lung alveolar type II cells. We have shown previously that ABCA3 mutations in fatal surfactant deficiency impair intracellular localization or ATP hydrolysis of ABCA3 protein. However, the mechanisms underlying the less severe phenotype of patients with ABCA3 mutation are unclear. In this study, we characterized ABCA3 mutant proteins identified in pediatric interstitial lung disease (pILD). E292V (intracellular loop 1), E690K (adjacent to Walker B motif in nucleotide binding domain 1), and T1114M (8th putative transmembrane segment) mutant proteins are localized mainly in intracellular vesicle membranes as wild-type protein. Lipid analysis and sucrose gradient fractionation revealed that the transport function of E292V mutant protein is moderately preserved, whereas those of E690K and T1114M mutant proteins are severely impaired. Vanadate-induced nucleotide trapping and photoaffinity labeling of wild-type and mutant proteins using 8-azido-[(32)P]ATP revealed an aberrant catalytic cycle in these mutant proteins. These results demonstrate the importance of a functional catalytic cycle in lipid transport of ABCA3 and suggest a pathophysiological mechanism of pILD due to ABCA3 mutation.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
12 E292V (intracellular loop 1), E690K (adjacent to Walker B motif in nucleotide binding domain 1), and T1114M (8th putative transmembrane segment) mutant proteins are localized mainly in intracellular vesicle membranes as wild-type protein. Login to comment
13 Lipid analysis and sucrose gradient fractionation revealed that the transport function of E292V mutant protein is moderately preserved, whereas those of E690K and T1114M mutant proteins are severely impaired. Login to comment
24 On the other hand, patients with the common missense mutation E292V and a second, specific mutation such as E690K or T1114M develop pediatric interstitial lung disease (pILD), the phenotype of which is milder than that of fatal surfactant deficiency, suggesting that the E292V ABCA3 mutation is responsible for the development of pILD (4). Login to comment
26 In this study, we characterized E292V, E690K, and T1114M mutant ABCA3 proteins identified in pILD. Login to comment
29 The plasmid pEGFPN1-ABCA3 (17), which encodes ABCA3 protein fused with enhanced green fluorescent protein (GFP) at the COOH terminus (ABCA3-GFP), and its mutants containing pILD mutations (E292V, E690K, and T1114M) and other site-directed mutations (E292D, E292K, T1114S, E690D, and E690R) were generated as described previously and used for transient transfection experiment. Login to comment
90 The E292V, E690K, and T1114M mutations identified in pILD (4) are located at intracellular loop 1 (ICL-1), adjacent to the Walker B motif in NBD-1 and the 8th putative transmembrane segment (TM-8), respectively (Fig. 1A). Login to comment
91 When E292V, E690K, and T1114M mutant ABCA3-GFP proteins were transiently expressed in HEK-293 cells, most of the GFP fluorescence was located at intracellular vesicles, as with the wild-type protein (Fig. 1B). Login to comment
97 In the E292V, E690K, and T1114M mutant proteins, 50-60% of the 220-kDa protein remained as Endo H-insensitive complex-type protein (Fig. 1E), indicating that intracellular trafficking and processing of oligosaccharide of these mutant proteins are largely preserved and that these mutations are not type I mutations. Login to comment
107 B: intracellular localization of GFP, wild-type ABCA3-GFP protein (WT), and its mutants (E292V, E690K, and T1114M) transiently expressed in human embryonic kidney HEK-293 cells were determined by confocal microscopy. Login to comment
117 The level of LAMP3 in E292V transfectant was comparable to that in wild-type transfectant, whereas those in E690K and T1114M transfectants were lower than in wild-type transfectant (Fig. 2A and Supplemental Fig. 1A). Login to comment
123 The levels of choline-phospholipids were significantly increased 1.38- and 1.13-fold in wild-type and E292V transfectants, respectively, compared with the level in HEK-293 cells, whereas levels in E690K and T1114M transfectants were similar to that in HEK-293 cells (Fig. 2B). Login to comment
132 In T1114M transfectant, choline-phospholipid content in fractions 2-4 was somewhat higher than that in HEK-293 cells, but the difference was not statistically significant (n ϭ 4, Supplemental Fig. 1C). Login to comment
133 Considered together, these results suggest that although the lipid transport function of the E292V mutant protein is moderate, those of the E690K and T1114M mutant proteins are severely impaired. Login to comment
136 Lipids transport function of wild-type ABCA3-GFP and pILD mutant proteins. A: Immunoblot analysis of the level of ABCA3-GFP, LAMP3, and GRP78 in HEK-293 cells stably expressing WT ABCA3-GFP, E292V, E690K, T1114M, or untransfected HEK-293 cells. Login to comment
151 In vanadate-induced nucleotide trapping by the E292V and T1114M mutant proteins, ATP hydrolysis with production of a photoaffinity-labeled intermediate was decreased to 40 and 52% of that of wild-type protein, respectively (Fig. 3A, lanes 5, 6, 9, and 10, and B). Login to comment
152 On the other hand, in the E690K mutant protein, it was increased to 200% of that of wild-type protein (Fig. 3A, lanes 7 and 8, and B). Login to comment
156 ATP binding of the E292V and T1114M mutant proteins determined by photoaffinity labeling with 8-azido-[␥-32 P]ATP was similar to that of wild-type ABCA3-GFP protein (Fig. 3, C and D). Login to comment
157 However, in E690K mutant protein, photoaffinity labeling of the 220-kDa protein was similar to that of wild type protein regardless of decreased noncleaved form protein, and photoaffinity labeling of the 180-kDa protein was dramatically enhanced even when the increased levels of the cleaved form of the protein were taken into consideration. Login to comment
161 To investigate the mechanism of loss of ATP hydrolysis with production of a photoaffinity-labeled intermediate in E292V and T1114M mutant proteins, we performed mutational analyses of Glu292 residue in ICL-1 and Thr1114 in putative TM-8. Login to comment
166 A: 20,000-g membrane fraction prepared from HEK-293 cells stably expressing the WT ABCA3-GFP (lanes 3 and 4), E292V (lanes 5 and 6), E690K (lanes 7 and 8), T1114M (lanes 9 and 10), or untransfected HEK-293 cells (lanes 1 and 2) was incubated with 10 ␮M 8-azido-[␣-32 P]ATP in the absence (-) or presence (ϩ) of 0.4 mM orthovanadate (Vi) and 3 mM MgCl2 for 10 min at 37°C. Protein was photoaffinity labeled with UV irradiation after removal of unbound ATP, electrophoresed on SDS-PAGE, and transferred to a PVDF membrane. Login to comment
171 C: 20,000-g membrane fraction prepared from HEK-293 cells stably expressing the WT ABCA3-GFP, E292V, E690K, T1114M, or untransfected HEK-293 cells was incubated with 40 ␮M 8-azido-[␥-32 P] and 3 mM MgCl2 for 10 min at 0°C. Protein was photoaffinity labeled with UV irradiation, immunoprecipitated with anti-human ABCA3 antibody, electrophoresed on SDS-PAGE, and transferred to a PVDF membrane. Membrane was analyzed by FLA-5000 (top) and IB using anti-GFP antibody (bottom). Login to comment
175 L702 CHARACTERIZATION OF ABCA3 MUTANTS ASSOCIATED WITH pILD AJP-Lung Cell Mol Physiol • VOL 295 022; OCTOBER 2008 • www.ajplung.org intermediate during ATP hydrolysis was decreased to 37% of that of wild-type protein, as also was the case in E292V mutant protein (Fig. 4B, lanes 5-8, and C). Login to comment
178 Recently, we identified a novel compound heterozygous mutation (maternal T1114A and paternal W1148X) from a Japanese boy with respiratory distress from age 18 mo (37). Login to comment
179 The T1114A mutation decreased vanadate-induced nucleotide trapping by ABCA3 protein similarly to the T1114M mutation. Login to comment
182 In vanadate-induced nucleotide trapping by T1114S mutant protein, production of a photoaffinity-labeled intermediate during ATP hydrolysis was found to be similar to that of wild-type protein, whereas that of T1114M and T1114A mutant protein was 56 and 47% of wild-type protein, respectively (Fig. 5B, lanes 5-10, and C). Login to comment
183 These results indicate that loss of the hydroxyl group of the 1114th amino acid is responsible for the impaired ATP hydrolysis with production of a photoaffinity-labeled intermediate in both the T1114M and T1114A mutant proteins. Login to comment
195 The amino acids residues that are conserved in 6 transporters and in 4 or 5 transporters are indicated by asterisks and dots, respectively. B: 20,000-g membrane fraction prepared from HEK-293 cells stably expressing the WT ABCA3-GFP (lanes 3 and 4), T1114M (lanes 5 and 6), T1114A (lanes 7 and 8), T1114S (lanes 9 and 10), or untransfected HEK-293 cells (lanes 1 and 2) was incubated with 10 ␮M 8-azido-[␣-32 P]ATP in the absence or presence of 0.4 mM Vi and 3 mM MgCl2 for 10 min at 37°C. 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
232 Accordingly, E292V, E690K, and T1114M are type II mutations. Login to comment
234 On the other hand, patients carrying a type II/type II ABCA3 mutation (E292V/T1114M or E292V/E690K) exhibit pILD (4), suggesting that the type II/type II ABCA3 mutation produces a milder phenotype. Login to comment
237 The E292V mutant protein exhibits moderately preserved lipid transport function and vanadate-induced nucleotide trapping, and mutational analysis of Glu292 in ICL-1 indicates the significance of both negative charge and side chain length of Glu292 for ATP hydrolysis with production of a photoaffinity-labeled intermediate in ABCA3 protein. Login to comment
240 The T1114M mutant protein exhibits impaired lipid transport function accompanied by moderately preserved vanadate-induced nucleotide trapping. 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
7 E292V (intracellular loop 1), E690K (adjacent to Walker B motif in nucleotide binding domain 1), and T1114M (8th putative transmembrane segment) mutant proteins are localized mainly in intracellular vesicle membranes as wild-type protein. Login to comment
8 Lipid analysis and sucrose gradient fractionation revealed that the transport function of E292V mutant protein is moderately preserved, whereas those of E690K and T1114M mutant proteins are severely impaired. Login to comment
19 On the other hand, patients with the common missense mutation E292V and a second, specific mutation such as E690K or T1114M develop pediatric interstitial lung disease (pILD), the phenotype of which is milder than that of fatal surfactant deficiency, suggesting that the E292V ABCA3 mutation is responsible for the development of pILD (4). Login to comment
21 In this study, we characterized E292V, E690K, and T1114M mutant ABCA3 proteins identified in pILD. Login to comment
86 The E292V, E690K, and T1114M mutations identified in pILD (4) are located at intracellular loop 1 (ICL-1), adjacent to the Walker B motif in NBD-1 and the 8th putative transmembrane segment (TM-8), respectively (Fig. 1A). Login to comment
87 When E292V, E690K, and T1114M mutant ABCA3-GFP proteins were transiently expressed in HEK-293 cells, most of the GFP fluorescence was located at intracellular vesicles, as with the wild-type protein (Fig. 1B). Login to comment
93 In the E292V, E690K, and T1114M mutant proteins, 50-60% of the 220-kDa protein remained as Endo H-insensitive complex-type protein (Fig. 1E), indicating that intracellular trafficking and processing of oligosaccharide of these mutant proteins are largely preserved and that these mutations are not type I mutations. Login to comment
103 B: intracellular localization of GFP, wild-type ABCA3-GFP protein (WT), and its mutants (E292V, E690K, and T1114M) transiently expressed in human embryonic kidney HEK-293 cells were determined by confocal microscopy. Login to comment
113 The level of LAMP3 in E292V transfectant was comparable to that in wild-type transfectant, whereas those in E690K and T1114M transfectants were lower than in wild-type transfectant (Fig. 2A and Supplemental Fig. 1A). Login to comment
119 The levels of choline-phospholipids were significantly increased 1.38- and 1.13-fold in wild-type and E292V transfectants, respectively, compared with the level in HEK-293 cells, whereas levels in E690K and T1114M transfectants were similar to that in HEK-293 cells (Fig. 2B). Login to comment
128 In T1114M transfectant, choline-phospholipid content in fractions 2-4 was somewhat higher than that in HEK293 cells, but the difference was not statistically significant (n afd; 4, Supplemental Fig. 1C). Login to comment
129 Considered together, these results suggest that although the lipid transport function of the E292V mutant protein is moderate, those of the E690K and T1114M mutant proteins are severely impaired. Login to comment
147 In vanadate-induced nucleotide trapping by the E292V and T1114M mutant proteins, ATP hydrolysis with production of a photoaffinity-labeled intermediate was decreased to 40 and 52% of that of wild-type protein, respectively (Fig. 3A, lanes 5, 6, 9, and 10, and B). Login to comment
162 A: 20,000-g membrane fraction prepared from HEK-293 cells stably expressing the WT ABCA3-GFP (lanes 3 and 4), E292V (lanes 5 and 6), E690K (lanes 7 and 8), T1114M (lanes 9 and 10), or untransfected HEK-293 cells (lanes 1 and 2) was incubated with 10 òe;M 8-azido-[ॷ-32 P]ATP in the absence (afa;) or presence (af9;) of 0.4 mM orthovanadate (Vi) and 3 mM MgCl2 for 10 min at 37&#b0;C. Protein was photoaffinity labeled with UV irradiation after removal of unbound ATP, electrophoresed on SDS-PAGE, and transferred to a PVDF membrane. Login to comment
167 C: 20,000-g membrane fraction prepared from HEK-293 cells stably expressing the WT ABCA3-GFP, E292V, E690K, T1114M, or untransfected HEK-293 cells was incubated with 40 òe;M 8-azido-[ॹ-32 P] and 3 mM MgCl2 for 10 min at 0&#b0;C. Protein was photoaffinity labeled with UV irradiation, immunoprecipitated with anti-human ABCA3 antibody, electrophoresed on SDS-PAGE, and transferred to a PVDF membrane. Membrane was analyzed by FLA-5000 (top) and IB using anti-GFP antibody (bottom). Login to comment
191 The amino acids residues that are conserved in 6 transporters and in 4 or 5 transporters are indicated by asterisks and dots, respectively. B: 20,000-g membrane fraction prepared from HEK-293 cells stably expressing the WT ABCA3-GFP (lanes 3 and 4), T1114M (lanes 5 and 6), T1114A (lanes 7 and 8), T1114S (lanes 9 and 10), or untransfected HEK-293 cells (lanes 1 and 2) was incubated with 10 òe;M 8-azido-[ॷ-32 P]ATP in the absence or presence of 0.4 mM Vi and 3 mM MgCl2 for 10 min at 37&#b0;C. Login to comment
227 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
229 Accordingly, E292V, E690K, and T1114M are type II mutations. Login to comment
231 On the other hand, patients carrying a type II/type II ABCA3 mutation (E292V/T1114M or E292V/E690K) exhibit pILD (4), suggesting that the type II/type II ABCA3 mutation produces a milder phenotype. 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

[hide] Clinical, radiological and pathological features o... Thorax. 2008 Apr;63(4):366-73. Epub 2007 Nov 16. Doan ML, Guillerman RP, Dishop MK, Nogee LM, Langston C, Mallory GB, Sockrider MM, Fan LL
Clinical, radiological and pathological features of ABCA3 mutations in children.
Thorax. 2008 Apr;63(4):366-73. Epub 2007 Nov 16., [PMID:18024538]

Abstract [show]
BACKGROUND: Mutations in the ABCA3 gene can result in fatal surfactant deficiency in term newborn infants and chronic interstitial lung disease in older children. Previous studies on ABCA3 mutations have focused primarily on the genetic abnormalities and reported limited clinical information about the resultant disease. A study was undertaken to analyse systematically the clinical presentation, pulmonary function, diagnostic imaging, pathological features and outcomes of children with ABCA3 mutations. METHODS: The records of nine children with ABCA3 mutations evaluated at Texas Children's Hospital between 1992 and 2005 were reviewed and their current clinical status updated. Previous diagnostic imaging studies and lung biopsy specimens were re-examined. The results of DNA analyses were confirmed. RESULTS: Age at symptom onset ranged from birth to 4 years. Cough, crackles, failure to thrive and clubbing were frequent findings. Mean lung function was low but tended to remain static. CT scans commonly revealed ground-glass opacification, septal thickening, parenchymal cysts and pectus excavatum. Histopathological patterns included pulmonary alveolar proteinosis, desquamative interstitial pneumonitis and non-specific interstitial pneumonitis, and varied with age. Dense abnormalities of lamellar bodies, characteristic of ABCA3 mutations, were seen by electron microscopy in all adequate specimens. Outcomes varied with the age at which the severity of lung disease warranted open lung biopsy, and some patients have had prolonged survival without lung transplantation. CONCLUSIONS: The presentation and course of interstitial lung disease due to ABCA3 mutations are variable, and open lung biopsy and genetic testing are warranted early in the evaluation of children with a consistent clinical picture.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
45 Five patients eventually Table 1 Characteristics of nine children with ABCA3 mutations Patient no Age of onset, manifestation Clinical features (age at evaluation) CT imaging (age at examination) Mutational analysis Outcomes (current age) 1 Newborn, respiratory failure Ta, Cr, Wh, Cl, Hy (4 years) GGO, ST, PE (2 weeks) Nt622C.T (R208W) Nt2279T.G (M760R) Transplanted (died) (5 years)* 2 Newborn, respiratory failure Ta, Hy (1 month) None Nt289insA Nt4648C.T (R1550W) Transplanted (died) (3 months)* 3 3 months, acute respiratory distress Ta, FTT, Hy (3 months) GGO, ST (3 months) Nt2646insC Nt3757C.T (P1253S) Died (4 months)* 4 2 years, acute respiratory distress Ta, Cr, Cl, FTT, Hy (2 years) GGO, ST, PE (2 years) Nt4732G.A (E1578K) Nt4772A.C (Q1591P) Alive, ILD score 4 (15 years) 5 1 year, recurrent hypoxaemia Ta, Cl, FTT, Hy (3 years) GGO, ST, PE, cysts (2 years) Nt59G.T (R20L) Nt2879T.C (L960S) Alive, ILD score 4 (8 years) 6 Newborn, pneumonia Ta, Cr, Cl, FTT, Hy (10 years) GGO, ST, PE (4 years) Nt875A.T (E292V) Nt3341C.T (T1114M) Transplanted (alive) (12 years)* 7 Newborn, respiratory failure Ta, Cl, FTT (6 years) GGO, ST, PE, cysts (6 years) Nt875A.T (E292V) Nt4706delTCA (deltaI1569) Alive, ILD score 1 (18 years) 8 Newborn, pneumonia Ta, Cr, Cl, Hy (6 years) GGO, PE (6 years) Nt629G.T (G210V) Nt3609delCTT (deltaF1203) Alive, ILD score 3 (11 years) 9 4 years, recurrent hypoxaemia Ta, Cr, Hy (exertional) (8 years) GGO, ST (7 years) Nt128G.A (R43H) Nt1609 in/del (end exon 13) Alive, ILD score 2 (13 years) Ta, tachypnoea; Cr, crackles; Wh, wheezing; Cl, clubbing; Hy, hypoxaemia; FTT, failure to thrive; GGO, ground-glass opacification; ST, septal thickening; PE, pectus excavatum. Login to comment

[hide] ABCA3 mutations associated with pediatric intersti... Am J Respir Crit Care Med. 2005 Oct 15;172(8):1026-31. Epub 2005 Jun 23. Bullard JE, Wert SE, Whitsett JA, Dean M, Nogee LM
ABCA3 mutations associated with pediatric interstitial lung disease.
Am J Respir Crit Care Med. 2005 Oct 15;172(8):1026-31. Epub 2005 Jun 23., [PMID:15976379]

Abstract [show]
RATIONALE: ABCA3 is a member of the ATP-binding cassette family of proteins that mediate the translocation of a wide variety of substrates, including lipids, across cellular membranes. Mutations in the gene encoding ABCA3 were recently identified in full-term neonates with fatal surfactant deficiency. OBJECTIVE: To test the hypothesis that ABCA3 mutations are not always associated with fatal neonatal lung disease but are a cause of pediatric interstitial lung disease. METHODS: DNA samples were obtained from 195 children with chronic lung disease of unknown etiology. The 30 coding exons of the ABCA3 gene were sequenced in four unrelated children with a referring diagnosis of desquamative interstitial pneumonitis and who were older than 10 years at the time of enrollment. RESULTS: Three of four patients (ages 16, 23, and 11 years) with desquamative interstitial pneumonitis had ABCA3 mutations identified on both alleles. All three had the same missense mutation (E292V) and a second unique mutation. The E292V mutation was not found on 200 control alleles from adults without lung disease, but seven additional patients of the remaining study patients had the E292V mutation on one allele. Immunohistochemical analysis of surfactant protein expression in three patients revealed a specific staining pattern for surfactant protein-B, which was the same pattern observed in several infants with fatal lung disease due to ABCA3 mutations. CONCLUSION: ABCA3 mutations cause some types of interstitial lung disease in pediatric patients.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
105 In addition to the E292V mutation, five additional missense variants (N1076K, G1302E, P1301L, T1114M, E690K) and three splice junction site mutations (c3704-1 GϾT, c1742-9 GϾA, c1612-2 AϾG) that would likely alter RNA splicing were identified. Login to comment
121 Some of this variability may reflect different stages of the disease and/or patchy distribution of disease within the lung, as well as TABLE 2. CHARACTERISTICS OF CHILDREN WITH CHRONIC LUNG DISEASE WHO SCREENED POSITIVE FOR E292V MUTATION Patient 5 Patient 6 Patient 7 Patient 8 Patient 9 Patient 10 Patient 11 Race White White White White White Hispanic White Age of symptoms Neonate Neonate Neonate 7 yr 5 yr Neonate Neonate Sex Female Female Male Male Male Male Male Lung biopsy Not done Not done Not done IP/PF Not done BO/fibrosis Normal Current age NA 11 yr 11 yr 11 yr 9 yr NA 6 yr Family history Yes No Yes Yes Yes No No Outcome Died at 11 yr Alive Alive Alive Alive Died at 6 mo Alive ABCA3 mutations E292V/c1612-2 E292V/G1302E E292V/T1114M E292V/E690K E292V/E690K E292V/none E292V/none AϾG/P1301L identified identified Definition of abbreviations: BO ϭ bronchiolitis obliterans; IP ϭ interstitial pneumonitis; NA ϭ not available; PF ϭ pulmonary fibrosis. Login to comment

[hide] Novel mutation in ABCA3 resulting in fatal congeni... Am J Respir Crit Care Med. 2014 Mar 15;189(6):750-2. doi: 10.1164/rccm.201312-2225LE. Moore GP, Lines MA, Geraghty MT, de Nanassy J, Kovesi T
Novel mutation in ABCA3 resulting in fatal congenital surfactant deficiency in two siblings.
Am J Respir Crit Care Med. 2014 Mar 15;189(6):750-2. doi: 10.1164/rccm.201312-2225LE., [PMID:24628317]

Abstract [show]

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
41 A nearby substitution, p.Thr1114Met, abolishes transporter activity of the mutant protein (7). Login to comment

[hide] Lost after translation: insights from pulmonary su... Am J Physiol Lung Cell Mol Physiol. 2015 Sep 15;309(6):L507-25. doi: 10.1152/ajplung.00139.2015. Epub 2015 Jul 17. Mulugeta S, Nureki S, Beers MF
Lost after translation: insights from pulmonary surfactant for understanding the role of alveolar epithelial dysfunction and cellular quality control in fibrotic lung disease.
Am J Physiol Lung Cell Mol Physiol. 2015 Sep 15;309(6):L507-25. doi: 10.1152/ajplung.00139.2015. Epub 2015 Jul 17., [PMID:26186947]

Abstract [show]
Dating back nearly 35 years ago to the Witschi hypothesis, epithelial cell dysfunction and abnormal wound healing have reemerged as central concepts in the pathophysiology of idiopathic pulmonary fibrosis (IPF) in adults and in interstitial lung disease in children. Alveolar type 2 (AT2) cells represent a metabolically active compartment in the distal air spaces responsible for pulmonary surfactant biosynthesis and function as a progenitor population required for maintenance of alveolar integrity. Rare mutations in surfactant system components have provided new clues to understanding broader questions regarding the role of AT2 cell dysfunction in the pathophysiology of fibrotic lung diseases. Drawing on data generated from a variety of model systems expressing disease-related surfactant component mutations [surfactant proteins A and C (SP-A and SP-C); the lipid transporter ABCA3], this review will examine the concept of epithelial dysfunction in fibrotic lung disease, provide an update on AT2 cell and surfactant biology, summarize cellular responses to mutant surfactant components [including endoplasmic reticulum (ER) stress, mitochondrial dysfunction, and intrinsic apoptosis], and examine quality control pathways (unfolded protein response, the ubiquitin-proteasome system, macroautophagy) that can be utilized to restore AT2 homeostasis. This integrated response and its derangement will be placed in the context of cell stress and quality control signatures found in patients with familial or sporadic IPF as well as non-surfactant-related AT2 cell dysfunction syndromes associated with a fibrotic lung phenotype. Finally, the need for targeted therapeutic strategies for pulmonary fibrosis that address epithelial ER stress, its downstream signaling, and cell quality control are discussed.

Comments [show]

None has been submitted yet.

Sentences [show]
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