Kleerebezem M, Quadri L E, Kuipers O P, de Vos W M
Department of Biophysical Chemistry, NIZO, Ede, The Netherlands.
Mol Microbiol. 1997 Jun;24(5):895-904. doi: 10.1046/j.1365-2958.1997.4251782.x.
Cell-density-dependent gene expression appears to be widely spread in bacteria. This quorum-sensing phenomenon has been well established in Gram-negative bacteria, where N-acyl homoserine lactones are the diffusible communication molecules that modulate cell-density-dependent phenotypes. Similarly, a variety of processes are known to be regulated in a cell-density- or growth-phase-dependent manner in Gram-positive bacteria. Examples of such quorum-sensing modes in Gram-positive bacteria are the development of genetic competence in Bacillus subtilis and Streptococcus pneumoniae, the virulence response in Staphylococcus aureus, and the production of antimicrobial peptides by several species of Gram-positive bacteria including lactic acid bacteria. Cell-density-dependent regulatory modes in these systems appear to follow a common theme, in which the signal molecule is a post-translationally processed peptide that is secreted by a dedicated ATP-binding-cassette exporter. This secreted peptide pheromone functions as the input signal for a specific sensor component of a two-component signal-transduction system. Moreover, genetic linkage of the common elements involved results in autoregulation of peptide-pheromone production.
细胞密度依赖性基因表达似乎在细菌中广泛存在。这种群体感应现象在革兰氏阴性菌中已得到充分证实，其中N-酰基高丝氨酸内酯是可扩散的通讯分子，可调节细胞密度依赖性表型。同样，已知革兰氏阳性菌中的多种过程以细胞密度或生长阶段依赖性方式受到调节。革兰氏阳性菌中这种群体感应模式的例子包括枯草芽孢杆菌和肺炎链球菌中遗传感受态的发展、金黄色葡萄球菌中的毒力反应，以及包括乳酸菌在内的几种革兰氏阳性菌产生抗菌肽。这些系统中的细胞密度依赖性调节模式似乎遵循一个共同的主题，即信号分子是一种经翻译后加工的肽，由专门的ATP结合盒式转运体分泌。这种分泌的肽信息素作为双组分信号转导系统特定传感器组件的输入信号。此外，所涉及的共同元件的遗传连锁导致肽信息素产生的自动调节。
