Szakacs, Gergely and Langmann, Thomas and Oezvegy, Csilla and Orso, Evelyn and Schmitz, Gerd and Varadi, András and Sarkadi, Balázs (2001) Characterization of the ATPase cycle of human ABCA1: Implications for its function as a regulator rather than an active transporter. BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS, 288 (5). pp. 1258-1264. ISSN 0006-291X
Full text not available from this repository. (Request a copy)Abstract
ABCA1 plays a key role in cellular cholesterol and phospholipid traffic. To explore the biochemical properties of this membrane protein we applied a Baculovirus-insect cell expression system. We found that human ABCA1 in isolated membranes showed a specific, Mg2+-dependent ATP binding but had no measurable ATPase activity. Nevertheless, conformational changes in ABCA1 could be demonstrated by nucleotide occlusion, even without arresting the catalytic cycle by phosphate-mimicking anions. Addition of potential lipid substrates or lipid acceptors (apolipoprotein A-I) did not modify the ATPase activity or nucleotide occlusion by ABCA1. Our data indicate that ATP hydrolysis by ABCA1 occurs at a very low rate, suggesting that ABCA1 may not function as an effective active transporter as previously assumed. In the light of the observed conformational changes we propose a regulatory function for human ABCA1. (C) 2001 Academic Press.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | BINDING CASSETTE TRANSPORTER-1; DENSITY-LIPOPROTEIN DEFICIENCY; TANGIER-DISEASE; APOPTOTIC CELLS; CHOLESTEROL EFFLUX; PLASMA-MEMBRANE; PROTEIN; ENGULFMENT; PHOSPHATIDYLSERINE; REDISTRIBUTION; human ABCA1; membrane protein; Baculovirus-insect cell expression system; ATP binding; ATPase activity; nucleotide occlusion; cholesterol and lipid metabolism |
| Subjects: | 600 Technology > 610 Medical sciences Medicine |
| Divisions: | Medicine > Lehrstuhl für Klinische Chemie und Laboratoriumsmedizin |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 24 Nov 2021 09:29 |
| Last Modified: | 24 Nov 2021 09:29 |
| URI: | https://pred.uni-regensburg.de/id/eprint/40927 |
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