The vacuolar V1/V0-ATPase is involved in the release of the HOPS subunit Vps41 from vacuoles, vacuole fragmentation and fusion.
At yeast vacuoles, phosphorylation of the HOPS subunit Vps41 depends on the Yck3 kinase. In a screen for mutants that mimic the yck3Delta phenotype, in which Vps41 accumulates in vacuolar dots, we observed that mutants in the V0-part of the V0/V1-ATPase, in particular in vma16Delta, also accumulate Vps41. This accumulation is not due to a phosphorylation defect, but to reduced release of Vps41 from vma16Delta vacuoles. One reason could be a connection to vacuole fission, which is blocked in V-ATPase mutants. Vacuole fusion is not impaired between vacuoles lacking the V0-subunits Vma16 or Vma6 and wild-type vacuoles, whereas fusion between mutant vacuoles is reduced. Our data suggest a connection between vacuole biogenesis and membrane fusion.
Takeda
Kozue
K
Department of Biology, University of Osnabrück, Barbarastrasse 13, 49076 Osnabrück, Germany.
Cabrera
Margarita
M
Rohde
Jan
J
Bausch
Dirk
D
Jensen
Ole N
ON
Ungermann
Christian
C
D047389:Casein Kinase I / Q000235:genetics; D008561:Membrane Fusion; D009154:Mutation; D010766:Phosphorylation; D021381:Protein Transport; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics / Q000648:ultrastructure; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D025262:Vacuolar Proton-Translocating ATPases / Q000235:genetics / Q000378:metabolism*; D014617:Vacuoles / Q000201:enzymology*; D033921:Vesicular Transport Proteins / Q000378:metabolism*
D029701:Saccharomyces cerevisiae Proteins; C083878:VPS41 protein, S cerevisiae; D033921:Vesicular Transport Proteins; D047389:Casein Kinase I; C479667:YCK3 protein, S cerevisiae; D025262:Vacuolar Proton-Translocating ATPases