Deletion of PIN4 Suppresses the Protein Transport Defects Caused by sec12-4 Mutation in Saccharomyces cerevisiae
Deletion of PIN4 Suppresses the Protein Transport Defects Caused by sec12-4 Mutation in Saccharomyces cerevisiae
复制标题
PIN4 缺失抑制酿酒酵母 sec12-4 突变引起的蛋白质转运缺陷
DOI：
10.1159/000509633
复制
发表时间：
2020
影响因子：
3.9
通讯作者：
Nakano Akihiko
中科院分区：
文献类型：
--
作者：
Murakami-Sekimata Akiko;Sekimata Masayuki;Sato Natsumi;Hayasaka Yuto;Nakano Akihiko
新合成的分泌蛋白被释放到内质网（ER）的内腔中。分泌蛋白被外壳蛋白复合物II（COPII）囊泡所包围，并从内质网转运，通过高尔基体到达目的地。Sec 12 p是Sar 1 p的鸟嘌呤核苷酸交换因子，其启动COPII囊泡从ER出芽。Sar 1 p的激活Sec 12 p和随后的COPII涂层组装已得到很好的表征，但发生在Sec 12 p上游的事件仍不清楚。在这项研究中，我们分离了一种新的sec 12 -4基因外抑制因子，PIN 4/MDT 1，一种细胞周期检查点靶点。酵母双杂交筛选用于确定Pin 4/Mdt 1 p作为酪蛋白激酶I亚型Hrr 25 p的结合伴侣，我们以前已经确定为Sec 12 p功能的调节剂。PIN 4的缺失抑制了在sec 12 -4突变体中观察到的温度敏感性生长和部分蛋白质转运的缺陷。这项研究的结果表明，Pin 4p提供了Sec 12 p调制的新方面。
Newly synthesized secretory proteins are released into the lumen of the endoplasmic reticulum (ER). The secretory proteins are surrounded by coat protein complex II (COPII) vesicles, and transported from the ER and reach their destinations through the Golgi apparatus. Sec12p is a guanine nucleotide exchange factor for Sar1p, which initiates COPII vesicle budding from the ER. The activation of Sar1p by Sec12p and the subsequent COPII coat assembly have been well characterized, but the events that take place upstream of Sec12p remain unclear. In this study, we isolated the novel extragenic suppressor of sec12-4, PIN4/MDT1, a cell cycle checkpoint target. A yeast two-hybrid screening was used to identify Pin4/Mdt1p as a binding partner of the casein kinase I isoform Hrr25p, which we have previously identified as a modulator of Sec12p function. Deletion of PIN4 suppressed both defects of temperature-sensitive growth and the partial protein transport observed in sec12-4 mutants. The results of this study suggest that Pin4p provides novel aspects of Sec12p modulations.