ABCA3 p.Glu690Lys

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PMID: 22337229 [PubMed] Agrawal A et al: "An intronic ABCA3 mutation that is responsible for respiratory disease."
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30 To determine whether the aberrantly spliced transcripts were derived from the allele with the c.2068 G>A (p.E690K) mutation, primers were designed to amplify either the transcripts containing the intronic sequence or those that were normally spliced, by using a 3' primer located in the intronic sequence, or one that spanned exons 25 and 26.
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ABCA3 p.Glu690Lys 22337229:30:108
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33 Electrophoretic analysis of the restriction products demonstrated that the relevant Ban II restriction fragment derived from the aberrantly spliced transcripts was smaller than that derived from the normally spliced products, indicating the presence of the G allele (wild type) in those amplicons containing the intronic sequences, and the A allele (p.E690K mutation) in those containing normal splicing.
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ABCA3 p.Glu690Lys 22337229:33:352
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42 The mother was found to be heterozygous GA at position c.2068 (site of the p.E690K mutation) but was homozygous CC at position IVS25-98.
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ABCA3 p.Glu690Lys 22337229:42:77
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46 2068 G>A, (p.E690K) 17 23 24 TAT A GC GGG CTG ACA TCC 252627 Figure 1.  ABCA3 exons 25-26 aberrant splicing.
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ABCA3 p.Glu690Lys 22337229:46:13
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52 2068 A (p.E690K) eliminates Ban II site Size markers Ban II: + + Retained intron-specific amplicon Normal splice-specific amplicon Larger (645 bp) product indicates A at position 2068 586 bp 645 bp G A BanII sites 1872 bp 1865 bp P-intron P3-WT-span P1 P1 Figure 2.  Transcript-specific RT-PCR and Ban II restriction endonuclease digest.
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ABCA3 p.Glu690Lys 22337229:52:10
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53 ABCA3 cDNA showing allele with inserted intronic sequence corresponding to the non-p.E690K allele.
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ABCA3 p.Glu690Lys 22337229:53:85
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54 Using a BanII restriction digest, the known p.E690K mutation eliminates a restriction site in the -normally spliced amplicon, generating a larger product (645 bp vs. 586 bp), -confirming the intronic insertion is in trans to the previously identified mutation.
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ABCA3 p.Glu690Lys 22337229:54:46
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80 However, the mechanism to account for this larger aberrant transcript with an additional 249 bases Table 1.  Characteristics of subjects with one ABCA3 mutation Patient Ethnicity Presentation Allele 1 mutation Allele 2 mutation Findings consistent with ABCA3 deficiency Outcome A Caucasian Newborn, RDS p.E690K IVS25-98T Case patient; lung histopathology and EM Died B Caucasian RDS p.L941P IVS25-98T Family history of sibling with fatal RDS Died C Caucasian 8 y/old, ILD L212M ?
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ABCA3 p.Glu690Lys 22337229:80:311
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116 Genetic testing performed through the Johns Hopkins University DNA Diagnostic Lab revealed normal SFTPB and SFTPC gene sequences but a heterozygous mutation in ABCA3 (Nt2068G->A, p.E690K) that had previously been identified as disease causing (22,23).
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ABCA3 p.Glu690Lys 22337229:116:181
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135 Specific primers were created to generate amplicons expanding from the previously known mutation (p.E690K at exon 17) to the area of interest in intron 25.
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ABCA3 p.Glu690Lys 22337229:135:100
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PMID: 19861431 [PubMed] Park SK et al: "Identification and characterization of a novel ABCA3 mutation."
No. Sentence Comment
99 Type I mutations include L101P, L982P, L1553P, and Q1591P; type II mutations include E292V, N568D, E690K, T1114, G1221S, and L1580P (13, 14).
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ABCA3 p.Glu690Lys 19861431:99:99
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94 Type I mutations include L101P, L982P, L1553P, and Q1591P; type II mutations include E292V, N568D, E690K, T1114, G1221S, and L1580P (13, 14).
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ABCA3 p.Glu690Lys 19861431:94:99
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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
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.
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ABCA3 p.Glu690Lys 18676873:12:30
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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.
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ABCA3 p.Glu690Lys 18676873:13:153
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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).
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ABCA3 p.Glu690Lys 18676873:24:108
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ABCA3 p.Glu690Lys 18676873:24:196
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26 In this study, we characterized E292V, E690K, and T1114M mutant ABCA3 proteins identified in pILD.
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ABCA3 p.Glu690Lys 18676873:26:39
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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.
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ABCA3 p.Glu690Lys 18676873:29:196
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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).
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ABCA3 p.Glu690Lys 18676873:90:11
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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).
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ABCA3 p.Glu690Lys 18676873:91:3
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ABCA3 p.Glu690Lys 18676873:91:12
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95 In E690K mutant protein, the amount of the 180-kDa cleaved form was increased compared with that of wild-type protein.
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ABCA3 p.Glu690Lys 18676873:95:3
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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.
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ABCA3 p.Glu690Lys 18676873:97:14
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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.
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ABCA3 p.Glu690Lys 18676873:107:96
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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).
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ABCA3 p.Glu690Lys 18676873:117:108
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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).
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ABCA3 p.Glu690Lys 18676873:123:197
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131 In E690K transfectant, the distribution of choline-phospholipid content was similar to that in HEK-293 cells.
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ABCA3 p.Glu690Lys 18676873:131:3
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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).
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ABCA3 p.Glu690Lys 18676873:132:198
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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.
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ABCA3 p.Glu690Lys 18676873:133:140
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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.
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ABCA3 p.Glu690Lys 18676873:136:198
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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).
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ABCA3 p.Glu690Lys 18676873:152:26
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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.
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ABCA3 p.Glu690Lys 18676873:157:12
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158 When normalized to the level of ABCA3-GFP proteins (total 220-kDa noncleaved form plus 180-kDa cleaved form), photoaffinity labeling of the E690K mutant protein was increased to 250% of that of wild-type protein.
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ABCA3 p.Glu690Lys 18676873:158:140
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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.
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ABCA3 p.Glu690Lys 18676873:166:133
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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).
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ABCA3 p.Glu690Lys 18676873:171:101
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181 To clarify this, we substituted Thr1114 with Ser and examined vanadate-induced nucleotide trapping.
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ABCA3 p.Glu690Lys 18676873:181:117
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184 Interaction of E690K mutant ABCA3-GFP protein with nucleotides.
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ABCA3 p.Glu690Lys 18676873:184:15
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185 To investigate the mechanism of enhanced production of a photoaffinity-labeled intermediate during ATP hydrolysis in E690K mutant protein, we performed the trap- Fig. 4.
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ABCA3 p.Glu690Lys 18676873:185:117
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201 In this procedure, a posthydrolyzed trapped nucleotide should not be detected by vanadate-induced trapping because of hydrolytic loss of [␥-32 P]PO4. Indeed, in the presence of orthovanadate, photoaffinity labeling of wild-type and E690K mutant proteins with 8-azido-[␥-32 P]ATP was barely detectable (Fig. 6A).
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ABCA3 p.Glu690Lys 18676873:201:25
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ABCA3 p.Glu690Lys 18676873:201:239
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202 These data combined with vanadate-induced trapping using 8-azido- [␣-32 P]ATP indicate that E690K mutant protein hydrolyzes 8-azido-[␣-32 P]ATP and releases ␥-phosphate and that the nucleotide trapped by E690K mutant protein is mostly in the ADP form.
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ABCA3 p.Glu690Lys 18676873:202:45
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ABCA3 p.Glu690Lys 18676873:202:99
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ABCA3 p.Glu690Lys 18676873:202:225
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ABCA3 p.Glu690Lys 18676873:202:252
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203 In E690K mutant protein, ATP binding determined by photoaffinity labeling with 8-azido-[␥-32 P]ATP was dramatically increased compared with that of wild-type protein (see Fig. 3, C and D).
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ABCA3 p.Glu690Lys 18676873:203:3
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ABCA3 p.Glu690Lys 18676873:203:242
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204 To determine whether the E690K mutation alters ADP binding, we performed labeling experiments using 8-azido-[␣-32 P]ADP at 0°C.
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ABCA3 p.Glu690Lys 18676873:204:25
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205 In this condition, photoaffinity labeling of E690K mutant protein was comparable to that of wild-type ABCA3-GFP protein (Fig. 6, B and C), suggesting that ␥-phosphate of 8-azido-[␥-32 P]ATP contributes to enhanced photoaffinity labeling in E690K mutant protein.
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ABCA3 p.Glu690Lys 18676873:205:45
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ABCA3 p.Glu690Lys 18676873:205:254
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206 Since some mutations in the Glu residues following the Walker B motif have been reported to interfere with the ATP-hydrolysis cycle including the ADP release step (5, 24, 25, 33), we examined release of trapped nucleotides from wild-type and E690K mutant ABCA3-GFP proteins. A 20,000-g membrane fraction was first incubated for 10 min at 37°C with 8-azido-[␣-32 P]ATP in the presence of orthovanadate, and unbound nucleotides were removed by washing.
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ABCA3 p.Glu690Lys 18676873:206:16
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ABCA3 p.Glu690Lys 18676873:206:189
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ABCA3 p.Glu690Lys 18676873:206:242
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209 In contrast, in E690K mutant protein, trapped nucleotides were more slowly released than in wild-type protein, and photoaffinity labeling at 5 min was 73% of that at 0 min, suggesting that E690K mutant protein forms a more stable inhibitory intermediate after hydrolysis of 8-azido-[␣-32 P]ATP than wild-type protein.
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ABCA3 p.Glu690Lys 18676873:209:16
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ABCA3 p.Glu690Lys 18676873:209:108
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ABCA3 p.Glu690Lys 18676873:209:189
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210 Thus these data further suggest abnormal interaction with nucleotides in E690K mutant protein.
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ABCA3 p.Glu690Lys 18676873:210:73
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ABCA3 p.Glu690Lys 18676873:210:217
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212 To further clarify the enhanced production of a photoaffinity-labeled intermediate during ATP hydrolysis in E690K mutant, we performed mutational analyses of the Glu690 residue adjacent to the Walker B motif in NBD-1.
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ABCA3 p.Glu690Lys 18676873:212:108
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213 Because Glu and Lys are negatively and positively charged amino acids, respectively, alteration of charge at the 690th amino acid residue could well be responsible for the abnormal interaction with nucleotides in the E690K mutant.
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ABCA3 p.Glu690Lys 18676873:213:15
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ABCA3 p.Glu690Lys 18676873:213:217
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214 Accordingly, Glu690 was substituted with Asp and Arg, which are negatively and positively charged, respectively.
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ABCA3 p.Glu690Lys 18676873:214:109
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216 Interaction of E690K mutant ABCA3-GFP protein with nucleotides.
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ABCA3 p.Glu690Lys 18676873:216:15
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217 A: 20,000-g membrane fraction prepared from HEK-293 cells stably expressing the WT ABCA3-GFP (lanes 3 and 4) E690K (lanes 5 and 6), 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. Protein was photoaffinity labeled with UV irradiation after removal of unbound ATP, electrophoresed on SDS-PAGE, and transferred to a PVDF membrane. Membrane was analyzed by autoradiography (top) and IB using anti-GFP antibody (bottom).
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ABCA3 p.Glu690Lys 18676873:217:109
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218 B: 20,000-g membrane fraction prepared from HEK-293 cells stably expressing the WT ABCA3-GFP, E690K, or untransfected HEK-293 cells was incubated with 40 ␮M 8-azido-[␣-32 P]ADP 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).
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ABCA3 p.Glu690Lys 18676873:218:94
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221 D: 20,000-g membrane fraction prepared from HEK-293 cells stably expressing the WT ABCA3-GFP or E690K was first incubated for 10 min at 37°C with 10 ␮M 8-azido-[␣-32 P]ATP in the presence of orthovanadate, and unbound nucleotides were removed by washing.
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ABCA3 p.Glu690Lys 18676873:221:96
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228 These results show that both negative charge and side chain length of Glu690 are important for ATP hydrolysis of wild-type ABCA3 protein and that not only positive charge but also side chain length of Lys690 contribute to enhanced production of a photoaffinity-labeled intermediate during ATP hydrolysis in the E690K mutant protein.
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ABCA3 p.Glu690Lys 18676873:228:311
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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.
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ABCA3 p.Glu690Lys 18676873:230:16
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ABCA3 p.Glu690Lys 18676873:230:189
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232 Accordingly, E292V, E690K, and T1114M are type II mutations.
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ABCA3 p.Glu690Lys 18676873:232:20
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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.
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ABCA3 p.Glu690Lys 18676873:234:93
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245 In E690K mutant Fig. 7.
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ABCA3 p.Glu690Lys 18676873:245:3
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247 A: 20,000-g membrane fraction prepared from HEK-293 cells stably expressing the WT ABCA3-GFP (lanes 3 and 4), E690K (lanes 5 and 6), E690D (lanes 7 and 8), E690R (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. Protein was photoaffinity labeled with UV irradiation after removal of unbound ATP, electrophoresed on SDS-PAGE, and transferred to a PVDF membrane. Membrane was analyzed by autoradiography (top) and IB using anti-GFP antibody (bottom).
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ABCA3 p.Glu690Lys 18676873:247:110
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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.
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ABCA3 p.Glu690Lys 18676873:252:190
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ABCA3 p.Glu690Lys 18676873:252:273
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255 Furthermore, mutational analysis of Glu690 indicates that side chain length of Lys690 contributes to enhanced production of a photoaffinity-labeled intermediate during ATP hydrolysis in the E690K mutant protein.
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ABCA3 p.Glu690Lys 18676873:255:35
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ABCA3 p.Glu690Lys 18676873:255:190
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256 To clarify the origin of the abnormal interaction with nucleotides in E690K mutant protein, we modeled the structure of NBD-1 of ABCA3 based on the crystal structure of E. coli MalK using SWISS-MODEL (Supplemental Fig. 2).
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ABCA3 p.Glu690Lys 18676873:256:70
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ABCA3 p.Glu690Lys 18676873:256:142
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258 On the other hand, in the model of E690K mutant, the distance from side chain nitrogen of Lys690 to ␥-phosphate oxygen of ATP is ϳ3.6 Å.
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ABCA3 p.Glu690Lys 18676873:258:35
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ABCA3 p.Glu690Lys 18676873:258:121
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259 One possible interpretation of these biochemical results and modeling is that ionic interaction of Lys690 and ␥-phosphate of ATP in the E690K mutant protein may tighten the binding of ATP in NBD-1, resulting in delayed ADP release after ATP hydrolysis, probably in NBD-2.
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ABCA3 p.Glu690Lys 18676873:259:143
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261 Analysis using purified ABCA3 protein would further clarify the aberrant catalytic cycle and impaired lipid transport in E690K mutant protein.
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ABCA3 p.Glu690Lys 18676873:261:121
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265 Interestingly, in E690K mutant protein, the amount of 180-kDa cleaved form was increased compared with that of wild-type protein.
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ABCA3 p.Glu690Lys 18676873:265:18
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266 The increased level of 180-kDa cleaved form E690K mutant protein might be due to the abnormal nucleotide-bound conformation of E690K mutant protein being preferentially cleaved by enzymes within intracellular vesicles, compared with that in wild-type protein.
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ABCA3 p.Glu690Lys 18676873:266:44
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ABCA3 p.Glu690Lys 18676873:266:127
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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.
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ABCA3 p.Glu690Lys 18676873:7:30
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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.
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ABCA3 p.Glu690Lys 18676873:8:153
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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).
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ABCA3 p.Glu690Lys 18676873:19:108
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21 In this study, we characterized E292V, E690K, and T1114M mutant ABCA3 proteins identified in pILD.
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ABCA3 p.Glu690Lys 18676873:21:39
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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).
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ABCA3 p.Glu690Lys 18676873:86:11
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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).
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ABCA3 p.Glu690Lys 18676873:87:12
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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.
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ABCA3 p.Glu690Lys 18676873:93:14
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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.
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ABCA3 p.Glu690Lys 18676873:103:96
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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).
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ABCA3 p.Glu690Lys 18676873:113:108
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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).
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ABCA3 p.Glu690Lys 18676873:119:197
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127 In E690K transfectant, the distribution of choline-phospholipid content was similar to that in HEK293 cells.
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ABCA3 p.Glu690Lys 18676873:127:3
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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.
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ABCA3 p.Glu690Lys 18676873:129:140
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148 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).
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ABCA3 p.Glu690Lys 18676873:148:26
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153 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.
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ABCA3 p.Glu690Lys 18676873:153:12
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154 When normalized to the level of ABCA3-GFP proteins (total 220-kDa noncleaved form plus 180-kDa cleaved form), photoaffinity labeling of the E690K mutant protein was increased to 250% of that of wild-type protein.
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ABCA3 p.Glu690Lys 18676873:154:140
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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.
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ABCA3 p.Glu690Lys 18676873:162:133
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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).
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ABCA3 p.Glu690Lys 18676873:167:101
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180 Interaction of E690K mutant ABCA3-GFP protein with nucleotides.
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ABCA3 p.Glu690Lys 18676873:180:15
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198 Indeed, in the presence of orthovanadate, photoaffinity labeling of wild-type and E690K mutant proteins with 8-azido-[ॹ-32 P]ATP was barely detectable (Fig. 6A).
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ABCA3 p.Glu690Lys 18676873:198:82
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199 These data combined with vanadate-induced trapping using 8-azido- [ॷ-32 P]ATP indicate that E690K mutant protein hydrolyzes 8-azido-[ॷ-32 P]ATP and releases ॹ-phosphate and that the nucleotide trapped by E690K mutant protein is mostly in the ADP form.
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ABCA3 p.Glu690Lys 18676873:199:98
status: NEW
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ABCA3 p.Glu690Lys 18676873:199:222
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200 In E690K mutant protein, ATP binding determined by photoaffinity labeling with 8-azido-[ॹ-32 P]ATP was dramatically increased compared with that of wild-type protein (see Fig. 3, C and D).
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ABCA3 p.Glu690Lys 18676873:200:3
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207 Thus these data further suggest abnormal interaction with nucleotides in E690K mutant protein.
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ABCA3 p.Glu690Lys 18676873:207:73
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215 B: 20,000-g membrane fraction prepared from HEK-293 cells stably expressing the WT ABCA3-GFP, E690K, or untransfected HEK-293 cells was incubated with 40 òe;M 8-azido-[ॷ-32 P]ADP 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).
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ABCA3 p.Glu690Lys 18676873:215:94
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225 These results show that both negative charge and side chain length of Glu690 are important for ATP hydrolysis of wild-type ABCA3 protein and that not only positive charge but also side chain length of Lys690 contribute to enhanced production of a photoaffinity-labeled intermediate during ATP hydrolysis in the E690K mutant protein.
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ABCA3 p.Glu690Lys 18676873:225:311
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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.
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ABCA3 p.Glu690Lys 18676873:227:16
status: NEW
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ABCA3 p.Glu690Lys 18676873:227:189
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229 Accordingly, E292V, E690K, and T1114M are type II mutations.
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ABCA3 p.Glu690Lys 18676873:229:20
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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.
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ABCA3 p.Glu690Lys 18676873:231:93
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242 In E690K mutant Fig. 7.
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ABCA3 p.Glu690Lys 18676873:242:3
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244 A: 20,000-g membrane fraction prepared from HEK-293 cells stably expressing the WT ABCA3-GFP (lanes 3 and 4), E690K (lanes 5 and 6), E690D (lanes 7 and 8), E690R (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. Protein was photoaffinity labeled with UV irradiation after removal of unbound ATP, electrophoresed on SDS-PAGE, and transferred to a PVDF membrane. Membrane was analyzed by autoradiography (top) and IB using anti-GFP antibody (bottom).
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ABCA3 p.Glu690Lys 18676873:244:110
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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.
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ABCA3 p.Glu690Lys 18676873:249:273
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253 To clarify the origin of the abnormal interaction with nucleotides in E690K mutant protein, we modeled the structure of NBD-1 of ABCA3 based on the crystal structure of E. coli MalK using SWISS-MODEL (Supplemental Fig. 2).
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ABCA3 p.Glu690Lys 18676873:253:70
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262 Interestingly, in E690K mutant protein, the amount of 180-kDa cleaved form was increased compared with that of wild-type protein.
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ABCA3 p.Glu690Lys 18676873:262:18
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263 The increased level of 180-kDa cleaved form E690K mutant protein might be due to the abnormal nucleotide-bound conformation of E690K mutant protein being preferentially cleaved by enzymes within intracellular vesicles, compared with that in wild-type protein.
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ABCA3 p.Glu690Lys 18676873:263:44
status: NEW
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ABCA3 p.Glu690Lys 18676873:263:127
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PMID: 15976379 [PubMed] Bullard JE et al: "ABCA3 mutations associated with pediatric interstitial lung disease."
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.
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ABCA3 p.Glu690Lys 15976379:105:102
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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.
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ABCA3 p.Glu690Lys 15976379:121:759
status: NEW
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ABCA3 p.Glu690Lys 15976379:121:771
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124 However, both siblings with the E292V/E690K mutations reportedly did not develop symptoms of lung disease until 5 to 7 years of age.
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ABCA3 p.Glu690Lys 15976379:124:38
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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.
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ABCA3 p.Glu690Lys 26186947:267:2639
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PMID: 26295388 [PubMed] Paolini A et al: "Structural Features of the ATP-Binding Cassette (ABC) Transporter ABCA3."
No. Sentence Comment
111 In particular, we focused on the following mutations: p.E292V, p.E690K, p.R1333G, p.W1142X, p.Y1515X, and p.L1553P.
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ABCA3 p.Glu690Lys 26295388:111:65
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114 p.E690K reside in the NBD1, whereas p.Y1515X and p.L1553P are localized in the NBD2.
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ABCA3 p.Glu690Lys 26295388:114:2
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