Duncan L, Alper S, Arigoni F, Losick R, Stragier P
Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA.
Science. 1995 Oct 27;270(5236):641-4. doi: 10.1126/science.270.5236.641.
Cell fate is determined by cell-specific activation of transcription factor sigma F after asymmetric division during sporulation by Bacillus subtilis. The activity of sigma F is governed by SpoIIAA, SpoIIAB, and SpoIIE, a membrane protein localized at the polar septum. SpoIIAB binds to and inhibits sigma F, and SpoIIAA inhibits SpoIIAB, which prevents SpoIIAB from binding to sigma F. SpoIIAB is also a serine kinase that inactivates SpoIIAA. Here, it is demonstrated that SpoIIE dephosphorylates SpoIIAA-P and overcomes SpoIIAB-mediated inhibition of sigma F. The finding that SpoIIE is a serine phosphatase links asymmetric division to the pathway governing cell-specific gene transcription.
芽孢杆菌在形成芽孢过程中进行不对称分裂后，细胞命运由转录因子σF的细胞特异性激活决定。σF的活性受SpoIIAA、SpoIIAB和定位于极性隔膜的膜蛋白SpoIIE调控。SpoIIAB与σF结合并抑制其活性，而SpoIIAA抑制SpoIIAB，从而阻止SpoIIAB与σF结合。SpoIIAB还是一种丝氨酸激酶，可使SpoIIAA失活。在此，研究表明SpoIIE使SpoIIAA-P去磷酸化，从而克服SpoIIAB介导的对σF的抑制。SpoIIE是一种丝氨酸磷酸酶这一发现，将不对称分裂与控制细胞特异性基因转录的途径联系了起来。
