Multifunctional molecular switch essential for cell morphogenesis

细胞形态发生必需的多功能分子开关

• 批准号: 11480177
• 负责人: OHYA Yoshikazu
• 金额: $ 10.24万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11480177/
• 关键词: cell wall; yeast; GTPase; genetics; intragenic complementation; GTPase; 形態形成; 細胞膜; グルカン合成酵素; ゲラニルゲラニル化; Rho GTPase; call-1

In many eukaryotic organisms, Rho-type small GTPases are involved in the determinations of cell polarity and cell morphology. Rholp, one of the essential Rho-type small GTPases in the yeast Saccharomyces cerevisiae, is a multifunctional molecular switch involved in establishment of cell morphogenesis. We characterized systematically isolated temperature-sensitive mutations in the RH01 gene and identified two groups of rhol mutations (rholA and rholB) possessing distinct functional defects. Biochemical and cytological analyzes demonstrated that mutant cells of the rholA and rholB groups have defects in activation of Rholp effectors, Pkc1p kinas and 1, 3-β-glean syntheses (GS), respectively. Heteroallelic diploid strains with rholA and rholB mutations are able to grow even at the restrictive temperature of the corresponding homoallelic diploid strains, showing intragenic complementation. The ability to activate both of the essential Rholp rho1p proteins is restored in the heteroallelic diploid. Thus, each of the complementing rhol mutation groups abolishes a distinct function of Rho1p, activation of Pck1p kinase or GS activity.

在许多真核生物中，Rho类型的小GTP酶参与了细胞极性和细胞形态的决定。Rholp是酿酒酵母中必不可少的Rho型小GTP酶之一，是参与细胞形态发生的多功能分子开关。我们系统地鉴定了RH01基因的温度敏感突变，并鉴定出两组具有明显功能缺陷的突变(rholA和rholB)。生化和细胞学分析表明，rholA和rholB组突变细胞分别在激活Rholp效应器、Pkc1p激酶和1，3-β-Glean合成(GS)方面存在缺陷。具有rholA和rholB突变的异等位二倍体菌株即使在相应的同等位二倍体菌株的限制性温度下也能生长，表现出基因内的互补。在异等位二倍体中恢复了激活两种必需的Rholp Rho1p蛋白的能力。因此，每个互补的RHOL突变组取消了Rho1p的一个独特功能，即Pck 1p激酶的激活或GS的活性。

项目成果

McEwen,R.K.他: "Complementation analysis in PtdInsP kinase-deficient yeast mutants demonstrates that S.pombe and murine Fab1p homologues are phosphatidylinositol 3-phosphate 5-kinases"Journal of Biological Chemistry. 274. 33905-33912 (1999)

McEwen, R.K. 等人：“PtdInsP 激酶缺陷型酵母突变体的互补分析表明，粟酒裂殖酵母和鼠 Fab1p 同源物是磷脂酰肌醇 3-磷酸 5-激酶”，《生物化学杂志》274. 33905-33912 (1999)。

Abe, M.: "Yeast 1,3-β-Glucan Synthase Activity Is Inhibited by Phytosphing osine Localized to the Endoplasmic Reticulum"J. Biol. Chem.. 276. 26923-26930 (2001)

Abe, M.：“酵母 1,3-β-葡聚糖合酶活性受到位于内质网的植物鞘氨醇的抑制”J. Biol. 276. 26923-26930 (2001)

Saka, A.: "Complementing Yeast rho1 Mutation Groups with Distinct Functional Defects"J. Biol. Chem.. 276. 46165-46171 (2001)

Saka, A.：“用独特的功能缺陷补充酵母 rho1 突变组”J。

Inoue, S.B.: "Prenylation of Rho1p Is Required for Activation of Yeast 1,3-β-Clucan Synthase"J. Biol. Chem.. 274. 38119-38124 (1999)

Inoue, S.B.：“酵母 1,3-β-Clucan 合酶的激活需要 Rho1p 的异戊二烯化”，J. Biol. 274. 38119-38124 (1999)

McEwen, R.K.: "Complementation Analysis in PtdInsP Kinase-Deficient Yeast Mutants Demonstrates that Schizosaccharomyces pombe and Murine Fablp IIomologues Are Phosphatidylinositol 3-Phosphate 5-Kinases"J. Biol. Chem.. 274. 33905-33912 (1999)

McEwen, R.K.：“PtdInsP 激酶缺陷型酵母突变体的互补分析表明粟酒裂殖酵母和鼠 Fablp II 同源物是磷脂酰肌醇 3-磷酸 5-激酶”J。