Complex kinase requirements for Chlamydia trachomatis Tarp phosphorylation
Complex kinase requirements for Chlamydia trachomatis Tarp phosphorylation
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DOI：
10.1111/j.1574-6968.2008.01390.x
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发表时间：
2008-12-01
影响因子：
2.1
通讯作者：
Meyer, Thomas F.
中科院分区：
文献类型：
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作者：
Mehlitz, Adrian;Banhart, Sebastian;Meyer, Thomas F.
沙眼衣原体将效应蛋白 Tarp（易位肌动蛋白招募磷蛋白）易位到宿主细胞的细胞质中，在那里它被快速酪氨酸磷酸化。 Abl 和 Src 激酶与 Tarp 磷酸化有关；然而，我们观察到情况更为复杂。 Src 家族激酶的化学抑制证实了这些激酶在 Tarp 磷酸化中的作用。 Src、Yes、Fyn (SYF) 缺陷细胞的感染显示出 Tarp 磷酸化减弱但不完全阻断。在 SYF 背景下抑制 Abl 仍然不能完全阻断 Tarp 磷酸化。因此，我们测试了其他激酶，发现 Syk（而非 Btk 或 Jak2）是体外 Tarp 的有效激酶。在 SYF 背景下抑制 Syk 进一步阻断 Tarp 磷酸化。在这些条件下，夹杂物形成仍然正常进行。这些数据揭示了 Tarp 高度混杂的底物特性，并为宿主细胞感染期间 Tarp 磷酸化的进一步功能表征奠定了基础。
Chlamydia trachomatis translocates the effector protein Tarp (translocated actin-recruiting phosphoprotein) into the host cell cytoplasm where it is quickly tyrosine phosphorylated. Abl and Src kinases have been implicated in Tarp phosphorylation; however, we observed that the situation is more complex. Chemical inhibition of Src family kinases confirmed a role for these kinases in Tarp phosphorylation. Infection of Src, Yes, Fyn (SYF)-deficient cells showed a dampened, but incompletely blocked, Tarp phosphorylation. Inhibition of Abl in an SYF background still did not completely block Tarp phosphorylation. Consequently, we tested additional kinases and found that Syk, but not Btk or Jak2, is a potent kinase of Tarp in vitro. Inhibition of Syk in an SYF background further blocked Tarp phosphorylation. Under these conditions, inclusion formation still proceeded normally. These data reveal a highly promiscuous substrate property of Tarp and set the stage for further functional characterization of Tarp phosphorylation during host cell infection.