Burbulys D, Trach K A, Hoch J A
Department of Molecular and Experimental Medicine, Research Institute of Scripps Clinic, La Jolla, California 92037.
Cell. 1991 Feb 8;64(3):545-52. doi: 10.1016/0092-8674(91)90238-t.
Stage 0 sporulation (spo0) mutants of Bacillus subtilis are defective in the signal transduction system initiating sporulation. Two of the products of these genes, Spo0A and Spo0F, are related to response regulator components of two-component regulatory systems used to control environmental responses in bacteria. The Spo0F response regulator was found to be the primary substrate for phosphorylation by the sporulation-specific protein kinase, KinA. Phosphorylated Spo0F was the phosphodonor for a phosphotransferase, Spo0B, which transferred the phosphate group to the second response regulator, the transcription regulatory protein Spo0A. This phosphorelay provides a mechanism for signal gathering from several protein kinases using Spo0F as a secondary messenger. These divergent signals are integrated through Spo0B phosphotransferase to activate the Spo0A transcription factor. This system provides for many levels of control to prevent capricious induction of sporulation.
枯草芽孢杆菌的0期芽孢形成（spo0）突变体在启动芽孢形成的信号转导系统中存在缺陷。这些基因的两个产物Spo0A和Spo0F与用于控制细菌环境应答的双组分调节系统的应答调节子成分相关。发现Spo0F应答调节子是芽孢形成特异性蛋白激酶KinA磷酸化的主要底物。磷酸化的Spo0F是磷酸转移酶Spo0B的磷供体，Spo0B将磷酸基团转移至第二个应答调节子，即转录调节蛋白Spo0A。这种磷酸中继提供了一种利用Spo0F作为第二信使从几种蛋白激酶收集信号的机制。这些不同的信号通过Spo0B磷酸转移酶整合，以激活Spo0A转录因子。该系统提供了多层次的控制，以防止芽孢形成的随意诱导。
