The forespore line of gene expression in Bacillus subtilis
The forespore line of gene expression in Bacillus subtilis
复制标题
DOI：
10.1016/j.jmb.2006.01.059
复制
发表时间：
2006-04-21
影响因子：
5.6
通讯作者：
Eichenberger, P
中科院分区：
文献类型：
--
作者：
Wang, ST;Setlow, B;Eichenberger, P
枯草芽孢杆菌的内孢子形成涉及三种分化细胞类型，即分裂前细胞、母细胞和前孢子。在这里，我们报道了基因在前孢子中的表达程序，该程序由RNA聚合酶sigma因子sigma(F)和sigma(G)以及dna结合蛋白RsfA和SpoVT控制。sigma(F)因子启动了大约48个基因，包括抑制sigma(F)调控中的一个基因的RsfA基因和sigma(G)基因。sigma(G)因子新激活了81个基因，其中包括SpoVT基因，它在9个案例中开启或刺激（在11个案例中）。在病例中，被sigma(G)激活的20个基因的表达被抑制，另外27个基因的表达被抑制。基因表达的前孢子系由许多参与孢子形态发生、抗性和萌发特性的基因组成，但很少有代谢功能的基因。比较基因组学揭示了sigma(F)和sigma(G)调控的核心基因，这些基因在孢子内形成物种中广泛保守，但在密切相关的非孢子形成李斯特菌中却不存在。sigma(G)调控的两个部分保守基因（ykoU和ykoV）被证明具有对休眠孢子的干热抗性。ykoV基因产物是非同源末端连接蛋白Ku的同源物，在萌发过程中与类核结合。扩展早期在分裂前细胞和母细胞中基因表达的工作，我们提出了孢子形成基因表达的整个程序的综合概述。(c) 2006 Elsevier Ltd.版权所有。
Endospore formation by Bacillus subtilis involves three differentiating cell types, the predivisional cell, the mother cell, and the forespore. Here we report the program of gene expression in the forespore, which is governed by the RNA polymerase sigma factors sigma(F) and sigma(G) and the DNA-binding proteins RsfA and SpoVT. The sigma(F) factor turns on about 48 genes, including the gene for RsfA, which represses a gene in the sigma(F) regulon, and the gene for sigma(G). The sigma(G) factor newly activates 81 genes, including the gene for SpoVT, which turns on (in nine cases) or stimulates (in 11. cases) the expression of 20 genes that had been turned on by sigma(G) and represses the expression of 27 others. The forespore line of gene expression consists of many genes that contribute to morphogenesis and to the resistance and germination properties of the spore but few that have metabolic functions. Comparative genomics reveals a core of genes in the sigma(F) and sigma(G) regulons that are widely conserved among endospore-forming species but are absent from closely related, but non-spore-forming Listeria spp. Two such partially conserved genes (ykoU and ykoV), which are members of the sigma(G) regulon, are shown to confer dry-heat resistance to dormant spores. The ykoV gene product, a homolog of the non-homologous end-joining protein Ku, is shown to associate with the nucleoid during germination. Extending earlier work on gene expression in the predivisional cell and the mother cell, we present an integrated overview of the entire program of sporulation gene expression. (c) 2006 Elsevier Ltd. All rights reserved.