Hofmeister A E, Londoño-Vallejo A, Harry E, Stragier P, Losick R
Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
Cell. 1995 Oct 20;83(2):219-26. doi: 10.1016/0092-8674(95)90163-9.
We present biochemical evidence for an intercellular signal transduction pathway in B. subtilis. This pathway governs the conversion of the proprotein pro-sigma E to mature transcription factor sigma E. Proteolytic processing is mediated by the membrane protein SpollGA and is triggered by the inferred extracellular signal protein SpollR. A factor in conditioned medium from B. subtilis cells engineered to produce SpollR during growth triggered processing in protoplasts of B. subtilis cells that had been engineered to produce SpollGA and pro-sigma E. The factor was also detected in, and partially purified from, extracts of SpollR-producing cells of E. coli. We speculate that SpollGA is both a receptor and a protease and the SpollR interacts with SpollGA on the outside of the cytoplasmic membrane, activating the intracellular protease domain of SpollGA.
我们提供了枯草芽孢杆菌中细胞间信号转导途径的生化证据。该途径控制前蛋白前σE向成熟转录因子σE的转化。蛋白水解加工由膜蛋白SpoIIGA介导，并由推断的细胞外信号蛋白SpoIIR触发。来自在生长过程中经改造产生SpoIIR的枯草芽孢杆菌细胞的条件培养基中的一种因子，可触发经改造产生SpoIIGA和前σE的枯草芽孢杆菌细胞原生质体中的加工过程。该因子也在大肠杆菌产生SpoIIR的细胞提取物中被检测到，并从中部分纯化出来。我们推测SpoIIGA既是一种受体也是一种蛋白酶，并且SpoIIR在细胞质膜外侧与SpoIIGA相互作用，激活SpoIIGA的细胞内蛋白酶结构域。
