The Pseudomonas aeruginosa ribbon-helix-helix DNA-Binding protein AlgZ (AmrZ) controls twitching motility and biogenesis of type IV pili
The Pseudomonas aeruginosa ribbon-helix-helix DNA-Binding protein AlgZ (AmrZ) controls twitching motility and biogenesis of type IV pili
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DOI：
10.1128/jb.188.1.132-140.2006
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发表时间：
2006-01-01
影响因子：
3.2
通讯作者：
Wozniak, DJ
中科院分区：
文献类型：
--
作者：
Baynham, PJ;Ramsey, DM;Wozniak, DJ
铜绿假单胞菌是一种常见于水和土壤中的条件致病菌。为了在低含水率的表面定植，铜绿假单胞菌利用一种不依赖鞭毛的运动形式，称为抽动运动，这种运动依赖于W型菌毛的伸展和收缩。这项研究表明，Algate生物合成操纵子转录所必需的DNA结合蛋白，是抽动运动所必需的。IV型菌毛的生物发生或在抽动运动中的功能可能需要阿尔茨海默氏菌。非粘液性PAO1中的海藻缺失的透射电子显微镜分析未能检测到表面菌毛。为了检测PilA(主要的Pilin亚基)的表达和定位，用Western blotting分析了全细胞提取液和细胞表面的Pilin制剂。野生型铜绿假单胞菌和野生型铜绿假单胞菌全细胞提取液中的PilA含量与野生型铜绿假单胞菌相似，但在algZ突变体中，细胞表面的PilA含量显著减少。对algZ和algD突变体的分析表明，algZ的DNA结合活性是调节抽动运动所必需的，并且这一活性独立于algZ在藻酸盐表达中的作用。这些数据表明，ALZDNA结合活性是抽动运动所必需的，与其在藻酸盐生产中的作用无关，这涉及IV型菌毛的表面定位。鉴于这一在抽动运动中的新作用，我们建议将algZ(PA3385)命名为amrZ(藻酸盐和运动调节剂Z)。
Pseudomonas aeruginosa is an opportunistic pathogen that is commonly found in water and soil. In order to colonize surfaces with low water content, P. aeruginosa utilizes a flagellum-independent form of locomotion called twitching motility, which is dependent upon the extension and retraction of type W pili. This study demonstrates that AlgZ, previously identified as a DNA-binding protein absolutely required for transcription of the allginate biosynthetic operon, is required for twitching motility. AlgZ may be required for the biogenesis or function of type IV pili in twitching motility. Transmission electron microscopy analysis of an algZ deletion in nonmucoid PAO1 failed to detect surface pili. To examine expression and localization of PilA (the major pilin subunit), whole-cell extracts and cell surface pilin preparations were analyzed by Western blotting. While the PilA levels present in whole-cell extracts were similar for wild-type P. aeruginosa and P. aeruginosa with the algZ deletion, the amount of PilA on the surface of the cells was drastically reduced in the algZ mutant. Analysis of algZ and algD mutants indicates that the DNA-binding activity of AlgZ is essential for the regulation of twitching motility and that this is independent of the role of AlgZ in alginate expression. These data show that AlgZ DNA-binding activity is required for twitching motility independently of its role in alginate production and that this involves the surface localization of type IV pili. Given this new role in twitching motility, we propose that algZ (PA3385) be designated amrZ (alginate and motility regulator Z).