Protein tyrosine phosphorylation by dual specificity kinases in M. tuberculosis

描述（由申请人提供）：细胞信号传导普遍受可逆蛋白质磷酸化控制。在原核生物中，组氨酸和天冬氨酸的磷酸化一直被认为是主要的信号传导机制，但丝氨酸（Ser），苏氨酸（Thr）和酪氨酸（Tyr）的磷酸化现在也同样重要。在结核分枝杆菌（Mtb）中，通过Ser/Thr磷酸化的信号传导是必需的。然而，尚未描述Tyr上的磷酸化，并且认为其不存在。我们现在首次在结核杆菌中显示蛋白质酪氨酸磷酸化。我们明确地检测到25个磷酸化位点的16种蛋白在一个单一的生长条件。我们显示了两种Mtb Ser/Thr激酶（STPKs）的酪氨酸磷酸化活性，表明某些STPKs是双特异性激酶。此外，我们表明，酪氨酸磷酸化控制的整体活动的基本STPK PknB。由于PknB对结核分枝杆菌生长至关重要，其他STPKs广泛调节结核分枝杆菌适应，酪氨酸磷酸化决定其他细菌的毒力，这些发现对结核分枝杆菌发病机制具有广泛的影响。在这里，我们将确定激酶和磷酸酶介导的Mtb蛋白磷酸化酪氨酸。

DESCRIPTION (provided by applicant): Cell signaling is universally controlled by reversible protein phosphorylation. In prokaryotes, phosphorylation on histidine and aspartate was long considered the main signaling mechanism, but phosphorylation on serine (Ser), threonine (Thr), and tyrosine (Tyr) is now emerging as equally important. In Mycobacterium tuberculosis (Mtb), signaling through Ser/Thr phosphorylation is essential. Phosphorylation on Tyr, however, has not yet been described and is thought to be absent. We now for the first time show protein tyrosine phosphorylation in Mtb. We unambiguously detected 25 phosphorylation sites on 16 proteins in a single growth condition. We show tyrosine phosphorylation activity of two Mtb Ser/Thr kinases (STPKs), suggesting that some STPKs are dual specificity kinases. Further, we show that Tyr phosphorylation controls the overall activity of the essential STPK PknB. Because PknB is essential for Mtb growth, other STPKs broadly regulate Mtb adaptations, and tyrosine phosphorylation determines virulence in other bacteria, these findings have wide implications for Mtb pathogenesis. Here, we will identify the kinases and phosphatases that mediate Mtb protein phosphorylation on Tyr.