文摘
| Figures/TablesFigures/Tables | ReferencesReferences
Summary
Studies of homotypic vacuole-vacuole fusion in the yeast Saccharomyces cerevisiae have been instrumental in determining the cellular machinery required for eukaryotic membrane fusion and have implicated the vacuolar H+-ATPase (V-ATPase). The V-ATPase is a multisubunit, rotary proton pump whose precise role in homotypic fusion is controversial. Models formulated from in聽vitro studies suggest that it is the proteolipid proton-translocating pore of the V-ATPase that functions in fusion, with further studies in worms, flies, zebrafish, and mice appearing to support this model. We present two in聽vivo assays and use a mutant V-ATPase subunit to establish that it is the H+-translocation/vacuole acidification function, rather than the physical presence of the V-ATPase, that promotes homotypic vacuole fusion in yeast. Furthermore, we show that acidification of the yeast vacuole in the absence of the V-ATPase rescues vacuole-fusion defects. Our results clarify the in聽vivo requirements of acidification for membrane fusion.
