Cycling of Etk and Etp phosphorylation states is involved in formation of group 4 capsule by Escherichia coli.
Cycling of Etk and Etp phosphorylation states is involved in formation of group 4 capsule by Escherichia coli.
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DOI：
10.1371/journal.pone.0037984
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发表时间：
2012
期刊：
影响因子：
3.7
通讯作者：
Rosenshine I
中科院分区：
文献类型：
--
作者：
Nadler C;Koby S;Peleg A;Johnson AC;Suddala KC;Sathiyamoorthy K;Smith BE;Saper MA;Rosenshine I
胶囊经常在细菌与环境的相互作用中发挥关键作用。大肠杆菌胶囊被分类为第1组至第4组，每组由不同的机制产生。Etk和Etp是生产第1组和第4组胶囊所需的蛋白质家族的成员。这些成员分别作为蛋白酪氨酸激酶和蛋白酪氨酸磷酸酶发挥功能。我们表明Etp在体内使Etk去磷酸化，并且使Etk或Etp催化失活的突变导致第4组胶囊产生的损失，支持Etk的循环磷酸化和去磷酸化是胶囊形成所需的观点。值得注意的是，Etp在体内也被酪氨酸磷酸化，并催化快速的自身去磷酸化。进一步分析鉴定Tyr121为Etp的磷酸化残基。含有Phe、Glu或Ala的Etp代替Tyr121保留磷酸酶活性并催化Etp和Etk的去磷酸化。虽然EtpY121E和EtpY121A仍然支持囊形成，但EtpY121F未能这样做。这些结果表明Etp以及Etk的磷酸化和去磷酸化循环参与了第4组胶囊的形成，为胶囊生产的复杂控制提供了额外的调节层。
Capsules frequently play a key role in bacterial interactions with their environment. Escherichia coli capsules were categorized as groups 1 through 4, each produced by a distinct mechanism. Etk and Etp are members of protein families required for the production of group 1 and group 4 capsules. These members function as a protein tyrosine kinase and protein tyrosine phosphatase, respectively. We show that Etp dephosphorylates Etk in vivo, and mutations rendering Etk or Etp catalytically inactive result in loss of group 4 capsule production, supporting the notion that cyclic phosphorylation and dephosphorylation of Etk is required for capsule formation. Notably, Etp also becomes tyrosine phosphorylated in vivo and catalyzes rapid auto-dephosphorylation. Further analysis identified Tyr121 as the phosphorylated residue of Etp. Etp containing Phe, Glu or Ala in place of Tyr121 retained phosphatase activity and catalyzed dephosphorylation of Etp and Etk. Although EtpY121E and EtpY121A still supported capsule formation, EtpY121F failed to do so. These results suggest that cycles of phosphorylation and dephosphorylation of Etp, as well as Etk, are involved in the formation of group 4 capsule, providing an additional regulatory layer to the complex control of capsule production.
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影响因子：
3.2
作者：
Shifrin, Yulia;Peleg, Adi;Rosenshine, Ilan
通讯作者：
Rosenshine, Ilan
影响因子：
3.2
作者：
Peleg, A;Shifrin, Y;Rosenshine, I
通讯作者：
Rosenshine, I
影响因子：
5.4
作者：
Blobel, Jascha;Bernado, Pau;Pons, Miquel
通讯作者：
Pons, Miquel
影响因子：
2.6
作者：
De Araujo, Cecilia;Balestrino, Damien;Forestier, Christiane
通讯作者：
Forestier, Christiane
DOI：
10.1073/pnas.120163297
发表时间：
2000-06-06
影响因子：
11.1
作者：
Datsenko, KA;Wanner, BL
通讯作者：
Wanner, BL