Expression profile and regulation of spore and parasporal crystal formation-associated genes in Bacillus thuringiensis.
Expression profile and regulation of spore and parasporal crystal formation-associated genes in Bacillus thuringiensis.
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DOI：
10.1021/pr4003728
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发表时间：
2013-11
影响因子：
4.4
通讯作者：
Jieping Wang;H. Mei;Hongliang Qian;Qing Tang;Xiaocui Liu;Ziniu Yu;Jin He
中科院分区：
文献类型：
--
作者：
Jieping Wang;H. Mei;Hongliang Qian;Qing Tang;Xiaocui Liu;Ziniu Yu;Jin He
苏云金芽孢杆菌（Bacillus thuringiensis）是一种革兰氏阳性的内孢子形成细菌，其特征在于在孢子形成过程中形成由杀虫晶体蛋白（ICP）组成的伴孢晶体。基于B的转录组学和蛋白质组学数据，我们揭示了与孢子和伴孢晶体形成相关的基因表达谱和调控机制。苏云金杆菌CT-43菌株在孢子形成过程中，CT-43编码的5个ICP基因被特异性转录;此外，大多数孢子结构、组装和成熟相关基因被特异性表达或显著上调，具有显著的时间调控特征。这些发现表明，在孢子形成过程中，细胞维持转录和翻译机制的有效运作是必不可少的。我们的研究结果表明，RNA聚合酶复合物δ和ω亚基，冷休克蛋白，sigma因子，转录因子以及丙酮酸脱氢酶复合物的E2亚基可以通过不同的机制协同参与转录调控。特别是，核糖体蛋白、rRNA和tRNA的加工和修饰的差异与翻译抑制的去阻遏相结合，可以提高核糖体回收和组装的速率以及翻译起始、延伸和终止效率，从而补偿核糖体水平的降低。因此，翻译机器的有效操作和强大的蛋白质质量控制系统将确保在孢子形成期间生物合成大量具有正常生物功能的蛋白质。
Bacillus thuringiensis, a Gram-positive endospore-forming bacterium, is characterized by the formation of parasporal crystals consisting of insecticidal crystal proteins (ICPs) during sporulation. We reveal gene expression profiles and regulatory mechanisms associated with spore and parasporal crystal formation based on transcriptomics and proteomics data of B. thuringiensis strain CT-43. During sporulation, five ICP genes encoded by CT-43 were specifically transcribed; moreover, most of the spore structure-, assembly-, and maturation-associated genes were specifically expressed or significantly up-regulated, with significant characteristics of temporal regulation. These findings suggest that it is essential for the cell to maintain efficient operation of transcriptional and translational machinery during sporulation. Our results indicate that the RNA polymerase complex δ and ω subunits, cold shock proteins, sigma factors, and transcriptional factors as well as the E2 subunit of the pyruvate dehydrogenase complex could cooperatively participate in transcriptional regulation via different mechanisms. In particular, differences in processing and modification of ribosomal proteins, rRNA, and tRNA combined with derepression of translational inhibition could boost the rate of ribosome recycling and assembly as well as translation initiation, elongation, and termination efficiency, thereby compensating for the reduction in ribosomal levels. The efficient operation of translational machineries and powerful protein-quality controlling systems would thus ensure biosyntheses of a large quantity of proteins with normal biological functions during sporulation.