大肠杆菌中 Kdp 在酸性条件下的表达和活性。

Expression and activity of Kdp under acidic conditions in Escherichia coli.

机构信息

Graduate School of Pharmaceutical Sciences, Chiba University, Japan.

出版信息

Biol Pharm Bull. 2011;34(3):426-9. doi: 10.1248/bpb.34.426.

DOI:10.1248/bpb.34.426

Abstract

Escherichia coli has three major K(+) uptake systems, Trk, Kup, and Kdp, which have been studied extensively at near neutral pH. However, the function of these transporters under acidic conditions is not well understood, although growth and survival under acidic conditions are important for bacterial pathogenesis. In this study, we examined the expression and activity of Kdp under acidic conditions and found that the transport activity of Kdp is decreased at low pH and that the expression of kdp is regulated by the internal K(+) concentration in a pH-independent manner. Consequently, the low activity of Kdp was compensated for by the induction of its elevated expression by low K(+) accumulation via Kdp at acidic pH.

摘要

大肠杆菌有三个主要的 K(+)摄取系统，Trk、Kup 和 Kdp，它们在接近中性 pH 值的条件下已经得到了广泛的研究。然而，这些转运蛋白在酸性条件下的功能还不是很清楚，尽管在酸性条件下的生长和存活对细菌的发病机制很重要。在这项研究中，我们研究了 Kdp 在酸性条件下的表达和活性，发现 Kdp 的转运活性在低 pH 值时降低，并且 kdp 的表达不受 pH 值影响，而是由内部 K(+)浓度调节的。因此，Kdp 的低活性通过 Kdp 在酸性 pH 值下积累低 K(+)来诱导其表达水平升高而得到补偿。