ABCMdb

PMID: 14754908

Krimbou L, Denis M, Haidar B, Carrier M, Marcil M, Genest J Jr
Molecular interactions between apoE and ABCA1: impact on apoE lipidation.
J Lipid Res. 2004 May;45(5):839-48. Epub 2004 Feb 1., [PubMed]

Sentences

No. Mutations Sentence Comment

5 ABCA1 p.Cys1477Arg Mutation of ABCA1 associated with Tangier disease (C1477R) abolished both apoE3 binding and apoE3-mediated cholesterol efflux. Login to comment 6 ABCA1 p.Cys1477Arg ABCA1 p.Cys1477Arg Analysis of apoE3-containing particles generated during the incubation of lipid-free apoE3 with stimulated normal cells showed nascent apoE3/ cholesterol/phospholipid complexes that exhibited prebeta- electrophoretic mobility with a particle size ranging from 9 to 15 nm, whereas lipid-free apoE3 incubated with ABCA1 mutant (C1477R) cells was unable to form such particles. Login to comment 31 ABCA1 p.Cys1477Arg MATERIALS AND METHODS Patient selection For the present study, we selected fibroblasts from three normal control subjects and one patient with TD (compound heterozygous carrying the mutations C1477R and the splice site G→C in exon 24) as previously described (16, 20). Login to comment 126 ABCA1 p.Cys1477Arg To determine whether naturally occurring mutants of ABCA1 might affect apoE3 binding, cross-linking of apoE3 to mutant ABCA1 (C1477R) was examined. Login to comment 127 ABCA1 p.Cys1477Arg As shown in Fig. 4, C1477R mutant abolished both apoE3 cross-linking and apoE3-mediated cholesterol efflux. Login to comment 128 ABCA1 p.Cys1477Arg On the other hand, C1477R mutant was found to be present at the plasma membrane, as determined by cell surface biotinylation (data not shown). Login to comment 129 ABCA1 p.Cys1477Arg To investigate the nature of apoE3-containing particles generated by ABCA1, stimulated cells from either normal control or TD (C1477R) subjects in 100 mm diameter dishes were incubated with 5 ␮g/ml lipid-free apoE3 in DMEM for 24 h at 37ЊC. Login to comment 174 ABCA1 p.Cys1477Arg A: Fibroblasts from a normal control and a Tangier disease (TD) (C1477R) subject were stimulated and incubated with 3 g/ml apoE3. Login to comment 175 ABCA1 p.Cys1477Arg ABCA1 p.Cys1477Arg A: Fibroblasts from a normal control and a Tangier disease (TD) (C1477R) subject were stimulated and incubated with 3 ␮g/ml apoE3. Login to comment 176 ABCA1 p.Cys1477Arg Cross-linking, immunoprecipitation, and detection of apoE3 associated with ABCA1 were performed as described in Materials and Methods. B: Fibroblasts from a normal control and a mutant (C1477R) subject were labeled with [3H]cholesterol and cholesterol-loaded, then stimulated for 20 h. Cells were incubated with 10 ␮g/ml apoE3 or apoA-I for 24 h, and cholesterol efflux was determined. Values represent means Ϯ SD from triplicate wells. Login to comment 184 ABCA1 p.Cys1477Arg In contrast, apoE3 incubated with TD cells (C1477R) was unable to form such particles (Fig. 5); because this is the plasma HDL-LpE3 size range having pre electrophoretic mobility (13), these particles are designated pre-LpE3-like particles. Login to comment 185 ABCA1 p.Cys1477Arg In contrast, apoE3 incubated with TD cells (C1477R) was unable to form such particles (Fig. 5); because this is the plasma HDL-LpE3 size range having prebeta electrophoretic mobility (13), these particles are designated prebeta-LpE3-like particles. Login to comment 187 ABCA1 p.Cys1477Arg These results are consistent with our Fig. 5. Characterization of lipidated apoE3-containing particles generated during apoE3 incubation with stimulated fibroblasts from a normal and a TD (C1477R) subject. Login to comment 188 ABCA1 p.Cys1477Arg These results are consistent with our Fig. 5. Characterization of lipidated apoE3-containing particles generated during apoE3 incubation with stimulated fibroblasts from a normal and a TD (C1477R) subject. Login to comment 195 ABCA1 p.Cys1477Arg observations that ABCA1 mutation in the second large extracellular loop (C1477R) abolished both apoE3 binding and apoE3-mediated cholesterol efflux (Fig. 4). Login to comment 198 ABCA1 p.Cys1477Arg observations that ABCA1 mutation in the second large extracellular loop (C1477R) abolished both apoE3 binding and apoE3-mediated cholesterol efflux (Fig. 4). Login to comment