Inhibition of Cdc42-dependent signalling in Saccharomyces cerevisiae by phosphatase-dead SigD/SopB from Salmonella typhimurium.
Inhibition of Cdc42-dependent signalling in Saccharomyces cerevisiae by phosphatase-dead SigD/SopB from Salmonella typhimurium.
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来自鼠伤寒沙门氏菌的磷酸酶死亡 SigD/SopB 对酿酒酵母中 Cdc42 依赖性信号传导的抑制。
DOI：
10.1099/mic.0.29186-0
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发表时间：
2006
期刊：
影响因子：
1.5
通讯作者：
M. Molina
中科院分区：
文献类型：
--
作者：
I. Rodríguez;R. Rotger;V. J. Cid;M. Molina
细菌毒力因子在酿酒酵母中的异源表达是研究其分子功能的可行途径。作者之前报道过鼠伤寒沙门氏菌SigD蛋白，一种参与入侵宿主细胞的磷脂酰肌醇磷酸酶，抑制酵母生长，可能是通过消耗磷脂酰肌醇4,5-二磷酸的基本池，还有一种催化无活性的SigD(R468A)，能够通过一种不同的机制阻止生长，这种机制涉及破坏肌动蛋白细胞骨架。本文描述了SigD和SigD（R468A）在酵母中表达所引起的表型之间的显著差异。首先，SigD（R468A）的表达引起了大的未出芽细胞的积累和septin组织的丧失，而SigD的表达没有引起这些影响。其次，SigD（R468A）的生长抑制是通过依赖于Swe1形态发生检查点的G2细胞周期阻滞介导的，但SigD诱导的生长抑制是独立于细胞周期的。第三，SigD引起酵母MAP激酶Slt2的强烈激活，而SigD（R468A）则使另一种MAP激酶Kss1失活。通过过表达酵母cDNA文库筛选SigD（R468A）诱导生长停滞的抑制因子，分离出Cdc42 GTPase。此外，从酵母裂解物中共纯化了SigD（R468A）和Cdc42。综上所述，被剥夺磷酸酶活性的沙门氏菌SigD蛋白能够通过干扰Cdc42的功能来破坏酵母的形态发生，从而开启了SigD n端区域在感染过程中直接调节宿主小gtpase的可能性。
Heterologous expression of bacterial virulence factors in Saccharomyces cerevisiae is a feasible approach to study their molecular function. The authors have previously reported that the Salmonella typhimurium SigD protein, a phosphatidylinositol phosphatase involved in invasion of the host cell, inhibits yeast growth, presumably by depleting an essential pool of phosphatidylinositol 4,5-bisphosphate, and also that a catalytically inactive version, SigD(R468A), was able to arrest growth by a different mechanism that involved disruption of the actin cytoskeleton. This paper describes marked differences between the phenotypes elicited by expression of SigD and SigD(R468A) in yeast. First, expression of SigD(R468A) caused accumulation of large unbudded cells and loss of septin organization, while SigD expression caused none of these effects. Second, growth inhibition by SigD(R468A) was mediated by a cell cycle arrest in G2 dependent on the Swe1 morphogenetic checkpoint, but SigD-induced growth inhibition was cell cycle independent. And third, SigD caused strong activation of the yeast MAP kinase Slt2, whereas SigD(R468A) rather inactivated another MAP kinase, Kss1. In a screen for suppressors of SigD(R468A)-induced growth arrest by overexpression of a yeast cDNA library, the Cdc42 GTPase was isolated. Furthermore, SigD(R468A) was co-purified with Cdc42 from yeast lysates. It is concluded that the Salmonella SigD protein deprived of its phosphatase activity is able to disrupt yeast morphogenesis by interfering with Cdc42 function, opening the possibility that the SigD N-terminal region might directly modulate small GTPases from the host during infection.
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影响因子：
4.1
作者：
Rodríguez-Escudero, I;Roelants, FM;Cid, VJ
通讯作者：
Cid, VJ
影响因子：
2.9
作者：
GUAN, KL;DIXON, JE
通讯作者：
DIXON, JE
DOI：
10.1073/pnas.87.24.9853
发表时间：
1990-12
影响因子：
11.1
作者：
K. Shinjo;J. Koland;Matthew J. Hart;Vikram Narasimhan;Douglas I. Johnson;T. Evans;R. Cerione
通讯作者：
K. Shinjo;J. Koland;Matthew J. Hart;Vikram Narasimhan;Douglas I. Johnson;T. Evans;R. Cerione
影响因子：
3.3
作者：
Sia, RAL;Herald, HA;Lew, DJ
通讯作者：
Lew, DJ
影响因子：
3.6
作者：
Zhou, DG;Chen, LM;Galán, JE
通讯作者：
Galán, JE