Sampedro Inmaculada, Kato Junichi, Hill Jane E
1 Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH, 03755, USA.
2 Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8530, Japan.
Microbiology (Reading). 2015 Jul;161(7):1496-503. doi: 10.1099/mic.0.000090. Epub 2015 Apr 8.
Previous studies have demonstrated that Pseudomonas aeruginosa PAO1 is chemotactic towards proteinogenic amino acids, however, the chemotaxis response of this strain towards non-proteinogenic amino acids and the specific chemoreceptors involved in this response are essentially unknown. In this study, we analysed the chemotactic response of PAO1 towards two degradation products of elastin, the lysine-rich, non-proteinogenic amino acids, desmosine and isodesmosine. We observed that isodesmosine, a potential biomarker for different diseases, served as a chemoattractant for PAO1. A screen of 251methyl-accepting chemotaxis proteins mutants of PAO1 identified PctA as the chemoreceptor for isodesmosine. We also showed that the positive chemotactic response to isodesmosine is potentially common by demonstrating chemoattraction in 12 of 15 diverse (in terms of source of isolation) clinical isolates, suggesting that the chemotactic response to this non-proteinogenic amino acid might be a conserved feature of acute infection isolates and thus could influence the colonization of potential infection sites.
先前的研究表明，铜绿假单胞菌PAO1对蛋白质氨基酸具有趋化性，然而，该菌株对非蛋白质氨基酸的趋化反应以及参与此反应的特定化学感受器基本上是未知的。在本研究中，我们分析了PAO1对弹性蛋白的两种降解产物——富含赖氨酸的非蛋白质氨基酸锁链素和异锁链素的趋化反应。我们观察到，异锁链素作为不同疾病的潜在生物标志物，可作为PAO1的化学引诱剂。对PAO1的251个甲基接受趋化蛋白突变体进行筛选，确定PctA为异锁链素的化学感受器。我们还表明，通过在15株不同（就分离来源而言）临床分离株中的12株中证明化学引诱作用，对异锁链素的正向趋化反应可能很常见，这表明对这种非蛋白质氨基酸的趋化反应可能是急性感染分离株的一个保守特征，因此可能影响潜在感染部位的定殖。
