Londoño-Vallejo J A, Stragier P
Institut de Biologie Physico-Chimique, Paris, France.
Genes Dev. 1995 Feb 15;9(4):503-8. doi: 10.1101/gad.9.4.503.
Transcription in the mother cell at early stages of sporulation in Bacillus subtilis is controlled by sigma E, a sigma factor that is synthesized in the predivisional cell as an inactive larger precursor, pro-sigma E. Activation of sigma E depends on sigma F, the factor that governs transcription in the forespore. Genetic experiments have indicated that transduction of the activation signal from the forespore to the mother cell requires the products of some genes belonging to the sigma F-controlled regulon. We have identified and characterized a sigma F-dependent gene, csfX, encoding a protein necessary and sufficient for triggering processing of pro-sigma E. The CsfX protein contains a typical amino-terminal signal sequence suggesting that, although synthesized in the forespore, it may act across the septum to activate the membrane-bound enzyme that is responsible for pro-sigma E processing in the mother cell.
枯草芽孢杆菌孢子形成早期母细胞中的转录由σE控制，σE是一种σ因子，在分裂前细胞中作为无活性的较大前体——前体σE合成。σE的激活依赖于σF，即控制前芽孢转录的因子。遗传学实验表明，激活信号从前芽孢传递到母细胞需要一些属于σF控制的调控子的基因产物。我们已经鉴定并表征了一个依赖于σF的基因csfX，它编码一种触发前体σE加工所必需且充分的蛋白质。CsfX蛋白含有典型的氨基末端信号序列，这表明尽管它在前芽孢中合成，但它可能穿过隔膜来激活负责母细胞中前体σE加工的膜结合酶。
