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Title: Phospholipid flippase activities and substrate specificities of human type IV P-type ATPases localized to the plasma membrane.
Authors: Takatsu, Hiroyuki
Tanaka, Gaku
Segawa, Katsumori
Suzuki, Jun
Nagata, Shigekazu
Nakayama, Kazuhisa  kyouindb  KAKEN_id  orcid (unconfirmed)
Shin, Hye-Won  kyouindb  KAKEN_id  orcid (unconfirmed)
Author's alias: 申, 惠媛
Keywords: ATPase
Lipid Bilayer
Lipid Transport
Plasma Membrane
Issue Date: 28-Nov-2014
Publisher: American Society for Biochemistry and Molecular Biology
Journal title: The Journal of biological chemistry
Volume: 289
Issue: 48
Start page: 33543
End page: 33556
Abstract: Type IV P-type ATPases (P4-ATPases) are believed to translocate aminophospholipids from the exoplasmic to the cytoplasmic leaflets of cellular membranes. The yeast P4-ATPases, Drs2p and Dnf1p/Dnf2p, flip nitrobenzoxadiazole-labeled phosphatidylserine at the Golgi complex and nitrobenzoxadiazole-labeled phosphatidylcholine (PC) at the plasma membrane, respectively. However, the flippase activities and substrate specificities of mammalian P4-ATPases remain incompletely characterized. In this study, we established an assay for phospholipid flippase activities of plasma membrane-localized P4-ATPases using human cell lines stably expressing ATP8B1, ATP8B2, ATP11A, and ATP11C. We found that ATP11A and ATP11C have flippase activities toward phosphatidylserine and phosphatidylethanolamine but not PC or sphingomyelin. By contrast, ATPase-deficient mutants of ATP11A and ATP11C did not exhibit any flippase activity, indicating that these enzymes catalyze flipping in an ATPase-dependent manner. Furthermore, ATP8B1 and ATP8B2 exhibited preferential flippase activities toward PC. Some ATP8B1 mutants found in patients of progressive familial intrahepatic cholestasis type 1 (PFIC1), a severe liver disease caused by impaired bile flow, failed to translocate PC despite their delivery to the plasma membrane. Moreover, incorporation of PC mediated by ATP8B1 can be reversed by simultaneous expression of ABCB4, a PC floppase mutated in PFIC3 patients. Our findings elucidate the flippase activities and substrate specificities of plasma membrane-localized human P4-ATPases and suggest that phenotypes of some PFIC1 patients result from impairment of the PC flippase activity of ATP8B1.
Rights: This research was originally published in [The Journal of Biological Chemistry, 289, 33543-33556. doi: 10.1074/jbc.M114.593012] © the American Society for Biochemistry and Molecular Biology
This is not the published version. Please cite only the published version. この論文は出版社版でありません。引用の際には出版社版をご確認ご利用ください。
DOI(Published Version): 10.1074/jbc.M114.593012
PubMed ID: 25315773
Appears in Collections:Journal Articles

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