期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1999
卷号：96
期号：20
页码：11194-11199
DOI：10.1073/pnas.96.20.11194
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Vacuole fusion occurs in three stages: priming, in which Sec18p mediates Sec17p release, LMA1 (low Mr activity 1) relocation, and cis-SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) complex disassembly; docking, mediated by Ypt7p and trans-SNARE association; and fusion of docked vacuoles. Ca2+ and calmodulin regulate late stages of the reaction. We now show that the vacuole proton gradient, generated by the vacuolar proton ATPase, is needed for trans-SNARE complex formation during docking and hence for the subsequent LMA1 release. Though neither the vacuolar Pmc1p Ca2+-ATPase nor the Vcx1p Ca2+/H+ exchanger are needed for the fusion reaction, they participate in Ca2+ and {Delta}{micro}H+ homeostasis. Fusion itself does not require the maintenance of trans-SNARE pairs.
