Institute of Molecular Biosciences, Massey University, Private Bag 11222, Palmerston North, New Zealand.
Fungal Genet Biol. 2009 Dec;46(12):927-35. doi: 10.1016/j.fgb.2009.07.008. Epub 2009 Jul 27.
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.
酵母细胞缺乏动力相关蛋白（DRP）Vps1 时，液泡体积变小，对低渗和高渗条件的反应分别为融合和裂变能力降低。vps1Δ细胞显示正常的液泡蛋白分选、肌动蛋白组织和内吞作用。vps1 的过表达将液泡从球形转变为管状。在有丝分裂条件下，管形成增强，需要 Rab 蛋白 Ypt7。在不存在第二种 DRP（Dnm1）的情况下，Vps1 引起的液泡管化更为广泛。dnm1Δ和双突变体 vps1Δdnm1Δ均表现出与 vps1Δ相似的液泡裂变缺陷。在 dnm1Δ中过表达 vps1，或在 vps1Δ中过表达 dnm1，均不能挽救这种表型。另一方面，在野生型细胞中过表达 dnm1 诱导液泡裂变。我们的结果与液泡裂变模型一致，其中 Vps1 产生适当直径的小管，随后由 Dnm1 进行分裂。
