The dynamin-related protein Vps1 regulates vacuole fission, fusion and tubulation in the fission yeast, Schizosaccharomyces pombe.
Fission yeast cells lacking the dynamin-related protein (DRP) Vps1 had smaller vacuoles with reduced capacity for both fusion and fission in response to hypotonic and hypertonic conditions respectively. vps1Delta cells showed normal vacuolar protein sorting, actin organisation and endocytosis. Over-expression of vps1 transformed vacuoles from spherical to tubular. Tubule formation was enhanced in fission conditions and required the Rab protein Ypt7. Vacuole tubulation by Vps1 was more extensive in the absence of a second DRP, Dnm1. Both dnm1Delta and the double mutant vps1Delta dnm1Delta showed vacuole fission defects similar to that of vps1Delta. Over-expression of vps1 in dnm1Delta, or of dnm1 in vps1Delta failed to rescue this phenotype. Over-expression of dnm1 in wild-type cells, on the other hand, induced vacuole fission. Our results are consistent with a model of vacuole fission in which Vps1 creates a tubule of an appropriate diameter for subsequent scission by Dnm1.
Röthlisberger
Sarah
S
Institute of Molecular Biosciences, Massey University, Private Bag 11222, Palmerston North, New Zealand.
Jourdain
Isabelle
I
Johnson
Chad
C
Takegawa
Kaoru
K
Hyams
Jeremy S
JS
D000199:Actins / Q000378:metabolism; D004271:DNA, Fungal / Q000235:genetics; D034281:Dynamins / Q000235:genetics / Q000378:metabolism*; D004705:Endocytosis; D015966:Gene Expression Regulation, Fungal; D006160:Guanosine Triphosphate / Q000378:metabolism; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D009154:Mutation; D021381:Protein Transport; D012568:Schizosaccharomyces / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000378:metabolism*; D014617:Vacuoles / Q000378:metabolism* / Q000648:ultrastructure; D020691:rab GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*
D000199:Actins; D004271:DNA, Fungal; D029702:Schizosaccharomyces pombe Proteins; D006160:Guanosine Triphosphate; C548065:Vps1 protein, S pombe; D020691:rab GTP-Binding Proteins; C498345:Dnm1 protein, S pombe; D034281:Dynamins