SlrR/SlrA controls the initiation of biofilm formation in Bacillus subtilis
SlrR/SlrA controls the initiation of biofilm formation in Bacillus subtilis
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DOI：
10.1111/j.1365-2958.2008.06369.x
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发表时间：
2008-09-01
影响因子：
3.6
通讯作者：
Kobayashi, Kazuo
中科院分区：
文献类型：
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作者：
Kobayashi, Kazuo
未驯化的枯草芽孢杆菌菌株在静置培养中可形成表膜生物膜。膜的形成是由鞭毛基因的抑制和eps和yqxM操纵子的激活启动的，这些操纵子参与生物膜基质的合成。SinI被认为通过拮抗eps和yqxM操纵子的阻遏物SinR来诱导eps和yqxM操纵子。在这里，我们表明，在后期鞭毛基因的突变，防止薄膜形成的起始步骤。这些突变降低了SlrR/SlrA的活性。SlrR（以前称为Slr）和SlrA分别是SinR和SinI的同源物，并且SlrR/SlrA抑制sigma（D）依赖性鞭毛基因并激活eps和yqxM操纵子。与以前的报道相反，sinI突变并不能阻止B中薄膜的形成。枯草杆菌菌株ATCC 6051。ATCC 6051在编码TetR型转录抑制因子的ywcC基因中具有移码突变。ywcC突变抑制slrA转录，从而增加SlrR/SlrA活性。在ywcC突变体中，SlrR/SlrA而不是SinI通过拮抗SinR激活eps和yqxM操纵子。讨论了SlrR/SlrA和鞭毛在膜形成起始中的作用。
Undomesticated strains of Bacillus subtilis can form pellicle biofilms in standing culture. Pellicle formation is initiated by repression of flagellar genes and activation of the eps and yqxM operons, which are involved in biofilm-matrix synthesis. SinI is thought to induce the eps and yqxM operons by antagonizing their repressor SinR. Here, we show that mutations in late-flagellar genes prevent pellicle formation at an initiation step. These mutations reduce the activity of SlrR/SlrA. SlrR (formerly Slr) and SlrA are homologues of SinR and SinI respectively, and SlrR/SlrA represses sigma(D)-dependent flagellar genes and activate the eps and yqxM operons. Contrary to previous reports, a sinI mutation does not prevent pellicle formation in B. subtilis strain ATCC 6051. ATCC 6051 has a frameshift mutation in the ywcC gene, which encodes a TetR-type transcriptional repressor. The ywcC mutation depresses slrA transcription, thereby increasing SlrR/SlrA activity. In the ywcC mutant, SlrR/SlrA rather than SinI activates the eps and yqxM operons by antagonizing SinR. The roles of SlrR/SlrA and flagella in the initiation of pellicle formation are discussed.