Overexpression of CupB5 activates alginate overproduction in Pseudomonas aeruginosa by a novel AlgW-dependent mechanism

文献类型： 外文期刊

第一作者： de Regt, Anna K.

作者： de Regt, Anna K.;Baker, Tania A.;Sauer, Robert T.;Yin, Yeshi;Withers, T. Ryan;Yu, Hongwei D.;Yu, Hongwei D.;Wang, Xin;Yu, Hongwei D.

作者机构：

期刊名称：MOLECULAR MICROBIOLOGY （ 影响因子：3.501； 五年影响因子：3.996 ）

ISSN：

年卷期：

页码：

收录情况： SCI

摘要： In Pseudomonas aeruginosa, alginate overproduction, also known as mucoidy, is negatively regulated by the transmembrane protein MucA, which sequesters the alternative sigma factor AlgU. MucA is degraded via a proteolysis pathway that frees AlgU from sequestration, activating alginate biosynthesis. Initiation of this pathway normally requires two signals: peptide sequences in unassembled outer-membrane proteins (OMPs) activate the AlgW protease, and unassembled lipopolysaccharides bind periplasmic MucB, releasing MucA and facilitating its proteolysis by activated AlgW. To search for novel alginate regulators, we screened a transposon library in the non-mucoid reference strain PAO1, and identified a mutant that confers mucoidy through overexpression of a protein encoded by the chaperone-usher pathway gene cupB5. CupB5-dependent mucoidy occurs through the AlgU pathway and can be reversed by overexpression of MucA or MucB. In the presence of activating OMP peptides, peptides corresponding to a region of CupB5 needed for mucoidy further stimulated AlgW cleavage of MucAin vitro. Moreover, the CupB5 peptide allowed OMP-activated AlgW cleavage of MucA in the presence of the MucB inhibitor. These results support a novel mechanism for conversion to mucoidy in which the proteolytic activity of AlgW and its ability to compete with MucB for MucA is mediated by independent peptide signals.

分类号： Q2

  • 相关文献
作者其他论文 更多>>

微信小程序