ABCMdb

PMID: 16709568

Trompier D, Alibert M, Davanture S, Hamon Y, Pierres M, Chimini G
Transition from dimers to higher oligomeric forms occurs during the ATPase cycle of the ABCA1 transporter.
J Biol Chem. 2006 Jul 21;281(29):20283-90. Epub 2006 May 18., [PubMed]

Sentences

No. Mutations Sentence Comment

120 ABCA1 p.Gln597Arg The first took advantage of the Q597R and èc;L693 mutations, previously shown to be massively retained in the endoplasmic reticulum (3), whereas the second set comprised mutants that, although correctly expressed and trafficked to the plasma membrane, showed reduced ability to elicit the functional phenotypes associated with ABCA1 expression in transfected cells. Login to comment 121 ABCA1 p.Gln597Arg ABCA1 p.Gln597Arg The first took advantage of the Q597R and ⌬L693 mutations, previously shown to be massively retained in the endoplasmic reticulum (3), whereas the second set comprised mutants that, although correctly expressed and trafficked to the plasma membrane, showed reduced ability to elicit the functional phenotypes associated with ABCA1 expression in transfected cells. Login to comment 122 ABCA1 p.Gln597Arg The analysis of lysates from cells transfected with EGFP-tagged Q597R or ⌬L693 mutants either alone or in combination with wild type ungrafted ABCA1 transporter indicated that three molecular species of dimers are detectable (Fig. 3A). Login to comment 127 ABCA1 p.Trp590Ser ABCA1 p.Cys1477Arg We chose to analyze W590S and C1477R, two Tangier-associated mutations previously characterized and known to differentially affect the ABCA1-induced binding of apoA-I and annexin V (3, 32). Login to comment 128 ABCA1 p.Trp590Ser ABCA1 p.Cys1477Arg We chose to analyze W590S and C1477R, two Tangier-associated mutations previously characterized and known to differentially affect the ABCA1-induced binding of apoA-I and annexin V (3, 32). Login to comment 132 ABCA1 p.Trp590Ser ABCA1 p.Cys1477Arg A:D ratio < 2.5 A:D ratio > 2.5 N-ter 14.86 afe; 1.4 19.11 afe; 1.3 YABCA1/CABCA1 n afd; 11 n afd; 17 Nand C-ter 17.72 afe; 2.1 18.91 afe; 2.312 C Y ABCA1/ABCA1 Y C n afd; 11 n afd; 8 C-ter 11.74 afe; 0.85 24.00 afe; 1.001 ABCA1Y/ABCA1C n afd; 29 n afd; 21 W590S 11.79 afe; 1.230 26.54 afe; 1.004 W590SY/W590SC n afd; 12 n afd; 30 C1477R 13.70 afe; 0.7299 26.50 afe; 1.462 C1477RY/C1477RC n afd; 27 n afd; 22 ABCA1MM 11.83 afe; 1.048 26.59 afe; 1.591 ABCA1MMY/ABCA1MMC n afd; 14 n afd; 15 Oligomerization of the ABCA1 Transporter 20286 JOURNAL OF BIOLOGICAL CHEMISTRY VOLUME 281ߦNUMBER 29ߦJULY 21, 2006 at SEMMELWEIS UNIV OF MEDICINE on December 3, constructs supported dimerization since an efficiency of the energy transfer similar to that of wild type and similarly sensitive to variations in acceptor-to-donor ratios was detected (Fig. 4, A and B, and Table 1). Login to comment 133 ABCA1 p.Trp590Ser ABCA1 p.Trp590Ser ABCA1 p.Cys1477Arg ABCA1 p.Cys1477Arg A:D ratio < 2.5 A:D ratio > 2.5 N-ter 14.86 Ϯ 1.4 19.11 Ϯ 1.3 YABCA1/CABCA1 n ϭ 11 n ϭ 17 Nand C-ter 17.72 Ϯ 2.1 18.91 Ϯ 2.312 C Y ABCA1/ABCA1 Y C n ϭ 11 n ϭ 8 C-ter 11.74 Ϯ 0.85 24.00 Ϯ 1.001 ABCA1Y/ABCA1C n ϭ 29 n ϭ 21 W590S 11.79 Ϯ 1.230 26.54 Ϯ 1.004 W590SY/W590SC n ϭ 12 n ϭ 30 C1477R 13.70 Ϯ 0.7299 26.50 Ϯ 1.462 C1477RY/C1477RC n ϭ 27 n ϭ 22 ABCA1MM 11.83 Ϯ 1.048 26.59 Ϯ 1.591 ABCA1MMY/ABCA1MMC n ϭ 14 n ϭ 15 Oligomerization of the ABCA1 Transporter 20286 constructs supported dimerization since an efficiency of the energy transfer similar to that of wild type and similarly sensitive to variations in acceptor-to-donor ratios was detected (Fig. 4, A and B, and Table 1). Login to comment 134 ABCA1 p.Trp590Ser ABCA1 p.Cys1477Arg However, upon fractionation on native PAGE, the lysates of cells transfected with W590S or C1477R showed a higher molecular mass band migrating at Ͼ800 kDa and accounting for 9 and 27%, respectively, of the total ABCA1 signal (Fig. 4C, upper panel), in the absence of any modification of expression levels as shown by the SDS-PAGE analysis (Fig. 4C, lower panel). Login to comment 175 ABCA1 p.Gln597Arg The mixtures contained equimolar amounts of ungrafted ABCA1 and of either Q597R or èc;L693 variants grafted with EGFP (Q597RG or èc;L693G). Login to comment 176 ABCA1 p.Gln597Arg ABCA1 p.Gln597Arg The mixtures contained equimolar amounts of ungrafted ABCA1 and of either Q597R or ⌬L693 variants grafted with EGFP (Q597RG or ⌬L693G). Login to comment 177 ABCA1 p.Gln597Arg For comparison, the banding profile of ungrafted (A1WT) and EYFP-grafted (A1Y) ABCA1 is shown. Detection was performed as indicated by either the 891.3 or the anti-GFP mAb. MW, molecular weight markers. B and C, confocal analysis of cells transfected with equimolar mixtures of wild type ABCA1 grafted with ECFP (A1C) and either Q597R or ⌬L693 grafted with EGFP indicate that the presence of wild type transporter in the dimers fails to rescue the trafficking defect of both variants. Login to comment 179 ABCA1 p.Trp590Ser ABCA1 p.Cys1477Arg A and B, imaging FRET of cells expressing appropriately tagged W590S or C1477R, two ABCA1 variants associated with Tangier disease and variably affecting the functional readouts associated with ABCA1 expression. Login to comment 180 ABCA1 p.Trp590Ser ABCA1 p.Cys1477Arg A and B, imaging FRET of cells expressing appropriately tagged W590S or C1477R, two ABCA1 variants associated with Tangier disease and variably affecting the functional readouts associated with ABCA1 expression. Login to comment 181 ABCA1 p.Trp590Ser C, upper panel, native PAGE profiles of lysates from cells transfected with ABCA1Y, W590S, W590SY, or C1477RY indicate that the two variants associated in dimers. Login to comment 182 ABCA1 p.Trp590Ser C, upper panel, native PAGE profiles of lysates from cells transfected with ABCA1Y, W590S, W590SY, or C1477RY indicate that the two variants associated in dimers. Login to comment