Identification of a developmentally regulated septin and involvement of the septins in spore formation in Saccharomyces cerevisiae
Identification of a developmentally regulated septin and involvement of the septins in spore formation in Saccharomyces cerevisiae
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DOI：
10.1083/jcb.132.3.399
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发表时间：
1996-02-01
影响因子：
7.8
通讯作者：
Pringle, JR
中科院分区：
文献类型：
--
作者：
Fares, H;Goetsch, L;Pringle, JR
酿酒酵母CDC3、CDC10、CDC11和CDC12基因编码一个相关蛋白家族，即septin，在营养生长过程中参与细胞分裂和细胞表面的组织。利用聚合酶链反应寻找其他酿酒葡萄球菌septin基因，鉴定出SPR3基因，该基因先前已根据其孢子特异性表达鉴定出。预测的SPR3产物在氨基酸序列上与酿酒酵母和其他生物的septin具有25-40%的同源性。免疫印迹证实了sppr3p的孢子特异性表达，并显示其他septin也大量存在于孢子细胞中。与表达数据一致，在两种遗传背景中，SPR3的缺失对呈指数增长的细胞没有可检测到的影响。在一种遗传背景下，尽管减数分裂似乎是正常完成的，但SPR3的缺失使孢子生成效率降低了三倍。在这种背景下，CDC10的缺失对孢子形成没有可检测到的影响。在另一项基因背景测试中，这两种缺失的结果是相反的。免疫荧光观察表明，Spr3p、Cdc3p和Cdc11p定位于纺锤极体附近形成的膜囊边缘，并逐渐延伸到包含单倍体染色体组的核裂片，从而形成孢子。SPR3的缺失并不会阻止Cdc3p和Cdc11p的定位，但这些蛋白的组织结构似乎较差，其染色强度降低。综上所述，结果表明，在孢子形成过程中，septin起着重要但部分多余的作用。
The Saccharomyces cerevisiae CDC3, CDC10, CDC11, and CDC12 genes encode a family of related proteins, the septins, which are involved in cell division and the organization of the cell surface during vegetative growth. A search for additional S. cerevisiae septin genes using the polymerase chain reaction identified SPR3, a gene that had been identified previously on the basis of its sporulation-specific expression. The predicted SPR3 product shows 25-40% identity in amino acid sequence to the previously known septins from S. cerevisiae and other organisms. Immunoblots confirmed the sporulation-specific expression of Spr3p and showed that other septins are also present at substantial levels in sporulating cells. Consistent with the expression data, deletion of SPR3 in either of two genetic backgrounds had no detectable effect on exponentially growing cells. In one genetic background, deletion of SPR3 produced a threefold reduction in sporulation efficiency, although meiosis appeared to be completed normally. In this background, deletion of CDC10 had no detectable effect on sporulation. In the other genetic background tested, the consequences of the two deletions were reversed. Immunofluorescence observations suggest that Spr3p, Cdc3p, and Cdc11p are localized to the leading edges of the membrane sacs that form near the spindle-pole bodies and gradually extend to engulf the nuclear lobes that contain the haploid chromosome sets, thus forming the spores. Deletion of SPR3 does not prevent the localization of Cdc3p and Cdc11p, but these proteins appear to be less well organized, and the intensity of their staining is reduced. Taken together, the results suggest that the septins play important but partially redundant roles during the process of spore formation.