Dissection of upstream regulatory components of the Rho1p effector, 1,3-beta-glucan synthase, in Saccharomyces cerevisiae.
Dissection of upstream regulatory components of the Rho1p effector, 1,3-beta-glucan synthase, in Saccharomyces cerevisiae.
复制标题
DOI：
--
复制
发表时间：
2002-10
期刊：
影响因子：
3.3
通讯作者：
M. Sekiya-Kawasaki;M. Abe;Ayaka Saka;D. Watanabe;Keiko Kono;Masayo Minemura-Asakawa;S. Ishihara;Takahide Watanabe;Y. Ohya
中科院分区：
文献类型：
--
作者：
M. Sekiya-Kawasaki;M. Abe;Ayaka Saka;D. Watanabe;Keiko Kono;Masayo Minemura-Asakawa;S. Ishihara;Takahide Watanabe;Y. Ohya
在芽殖酵母酿酒酵母（Saccharomyces cerevisiae）中，细胞壁的主要结构组分之一是由1，3-β-葡聚糖合酶（GS）产生的1，3-β-葡聚糖。酵母GS由FKS 1和FKS 2编码的推定催化亚基和RH 0 1编码的调节亚基组成。Fks 1 p的推定催化结构域中的氨基酸改变的组合被发现导致催化活性的损失。为了鉴定1，3-β-葡聚糖合成的上游调节因子，我们分离了GS突变的多拷贝抑制子。我们证明了所有获得的多拷贝抑制子（WSC 1、WSC 3、MTL 1、ROM 2、LRE 1、ZDS 1和MSB 1）和测试的组成型活性RHO 1突变恢复了GS突变体中的1，3-β-葡聚糖合成。ROM 2或WSC 1的缺失导致1，3-β-葡聚糖合成的显著缺陷。对Mpk 1 p磷酸化程度的分析表明，在多拷贝抑制子中，WSC 1、ROM 2、LRE 1、MSB 1和MTL 1对Pkc 1 p-MAPK通路（另一条受Rho 1 p调节的信号通路）起正作用，而WSC 3和ZDS 1则不起作用。我们还发现MID 2对Pkc 1 p起积极作用，而不影响1，3-β-葡聚糖的合成。这些结果表明，不同的网络调节两个效应蛋白Rho 1 p，Fks 1 p和Pkc 1 p。
In the budding yeast Saccharomyces cerevisiae, one of the main structural components of the cell wall is 1,3-beta-glucan produced by 1,3-beta-glucan synthase (GS). Yeast GS is composed of a putative catalytic subunit encoded by FKS1 and FKS2 and a regulatory subunit encoded by RHO1. A combination of amino acid alterations in the putative catalytic domain of Fks1p was found to result in a loss of the catalytic activity. To identify upstream regulators of 1,3-beta-glucan synthesis, we isolated multicopy suppressors of the GS mutation. We demonstrate that all of the multicopy suppressors obtained (WSC1, WSC3, MTL1, ROM2, LRE1, ZDS1, and MSB1) and the constitutively active RHO1 mutations tested restore 1,3-beta-glucan synthesis in the GS mutant. A deletion of either ROM2 or WSC1 leads to a significant defect of 1,3-beta-glucan synthesis. Analyses of the degree of Mpk1p phosphorylation revealed that among the multicopy suppressors, WSC1, ROM2, LRE1, MSB1, and MTL1 act positively on the Pkc1p-MAPK pathway, another signaling pathway regulated by Rho1p, while WSC3 and ZDS1 do not. We have also found that MID2 acts positively on Pkc1p without affecting 1,3-beta-glucan synthesis. These results suggest that distinct networks regulate the two effector proteins of Rho1p, Fks1p and Pkc1p.