Protein phosphorylation on serine, threonine, and tyrosine residues modulates membrane-protein interactions and transcriptional regulation in Salmonella typhimurium.
Protein phosphorylation on serine, threonine, and tyrosine residues modulates membrane-protein interactions and transcriptional regulation in Salmonella typhimurium.
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丝氨酸、苏氨酸和酪氨酸残基上的蛋白质磷酸化调节鼠伤寒沙门氏菌的膜蛋白相互作用和转录调控。
DOI：
10.1101/gad.9.16.2034
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发表时间：
1995
影响因子：
10.5
通讯作者：
Maloy,S
中科院分区：
文献类型：
--
作者：
Ostrovsky,PC;Maloy,S
存在过多的酪氨酸激酶在真核蛋白的调节中起重要作用。一些双特异性激酶磷酸化苏氨酸、丝氨酸和酪氨酸残基上的蛋白质，在真核磷酸化级联反应中也起着关键作用。相比之下，很少有原核蛋白被证明在酪氨酸残基上磷酸化，并且罕见的例子的功能仍然不清楚。此外，在原核生物中尚未发现双特异性激酶。我们的研究结果表明，鼠伤寒沙门氏菌中的PutA蛋白在几个苏氨酸、丝氨酸和酪氨酸残基上进行自磷酸化。PutA蛋白既抑制脯氨酸利用（put）操纵子，又将脯氨酸降解为谷氨酸。这两种相反的功能是由脯氨酸的可用性和PutA蛋白脯氨酸脱氢酶活性所需的膜位点调节的。此外，这些功能是由PutA蛋白磷酸化调节的。PutA蛋白的去磷酸化速率是由脯氨酸和膜的可用性决定的。去磷酸化的PutA蛋白比磷酸化的PutA蛋白具有更高的DNA结合亲和力，因此可以防止PutA蛋白在缺乏可用膜位点时的毒性过表达。
There exists a plethora of tyrosine kinases that play essential roles in regulation of eukaryotic proteins. Several dual specificity kinases that phosphorylate proteins on threonine, serine, and tyrosine residues also play critical roles in eukaryotic phosphorylation cascades. In contrast, very few prokaryotic proteins have been shown to be phosphorylated on tyrosine residues, and the functions of the rare examples remain obscure. Furthermore, no dual specificity kinases have been described in prokaryotes. Our results indicate that PutA protein from the bacterium Salmonella typhimurium autophosphorylates on several threonine, serine, and tyrosine residues. PutA protein both represses the proline utilization (put) operon and degrades proline to glutamate. These two opposing functions are regulated by the availability of proline and the membrane sites needed for the proline dehydrogenase activity of PutA protein. In addition, these functions are modulated by phosphorylation of PutA protein. The rate of dephosphorylation of PutA protein is determined by the availability of proline and membranes. Dephosphorylated PutA protein has a higher DNA binding affinity than the phosphorylated protein and thus may prevent toxic overexpression of PutA protein in the absence of available membrane sites.