Nakase Mai, Tsukamoto Yuta, Hosomi Akira, Matsuda Tomo, Miyamoto Masaaki, Takegawa Kaoru
Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Hakozaki, Fukuoka, Japan.
Biosci Biotechnol Biochem. 2012;76(4):652-9. doi: 10.1271/bbb.110609. Epub 2012 Apr 7.
The functions of two Schizosaccharomyces pombe Vps9-like genes, SPBC4F6.10/vps901(+) and SPBC29A10.11c/vps902(+), were characterized. Genomic sequence analysis predicted that Vps901p contains a VPS9 domain, whereas cDNA analyses revealed that Vps901p contains a CUE domain (coupling of ubiquitin to ER degradation) in its C-terminal region. Deletion of vps901(+) resulted in mis-sorting and secretion of S. pombe vacuolar carboxypeptidase Cpy1p, whereas deletion of vps902(+) had no effect, suggesting that only Vps901p functions in vacuolar protein transport in S. pombe. Deletion of vps901(+) further produced pleiotropic phenotypes, including vacuolar homotypic fusion and endocytosis defects. Heterologous expression of the budding yeast VPS9 gene corrected the CPY mis-sorting defect in vps901Δ cells. These findings suggest that the VPS9 domain of Vps901p is required for vacuolar protein trafficking in S. pombe.
对粟酒裂殖酵母两个类Vps9基因SPBC4F6.10/vps901(+)和SPBC29A10.11c/vps902(+)的功能进行了表征。基因组序列分析预测Vps901p含有一个VPS9结构域，而cDNA分析表明Vps901p在其C末端区域含有一个CUE结构域（泛素与内质网降解的偶联）。vps901(+)的缺失导致粟酒裂殖酵母液泡羧肽酶Cpy1p的分选错误和分泌，而vps902(+)的缺失没有影响，这表明只有Vps901p在粟酒裂殖酵母的液泡蛋白运输中发挥作用。vps901(+)的缺失进一步产生了多效性表型，包括液泡同型融合和内吞缺陷。芽殖酵母VPS9基因的异源表达纠正了vps901Δ细胞中的CPY分选错误缺陷。这些发现表明，Vps901p的VPS9结构域是粟酒裂殖酵母液泡蛋白运输所必需的。
