RT Journal Article
SR Electronic
T1 Characterization of the ATPase Activity of Human ATP-binding Cassette Transporter-2 (ABCA2)
JF In Vivo
JO In Vivo
FD International Institute of Anticancer Research
SP 657
OP 660
VO 19
IS 4
A1 VLADIMIR BELJANSKI
A1 ATHENA SOULIKA
A1 JODY M. TUCKER
A1 DANYELLE M. TOWNSEND
A1 WARREN DAVIS, JR.
A1 KENNETH D. TEW
YR 2005
UL http://iv.iiarjournals.org/content/19/4/657.abstract
AB Background: ABCA2 is a member of the ATP binding cassette transporter family with functional roles in cholesterol homeostasis and drug resistance. Materials and Methods: In order to characterize its ATPase activity, we transfected HEK293 cells with an ABCA2 mammalian expression system and isolated ABCA2-enriched membranes. Results: We found no measurable ATPase activity of ABCA2 in isolated membranes, except in the presence of the methyl-β-cyclodextrin. However, competitive binding of a pseudo-substrate, 8-azido-[α-32P]-ATP, was demonstrated. CHO cells transfected with ABCA2 did not have a higher rate of endogenous ATP hydrolysis when compared to the mock-transfected cells. Conclusion: Overall, we conclude that, while ABCA2 may have low levels of ATPase activity that can be substrate-stimulated, it is more likely to have a regulatory role in cell physiology. Copyright © 2005 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved