Vol.59 No.1 January 2011

Small RNA-mediated bacterial multidrug resistance

Kunihiko Nishino^1,4), Seiji Yamasaki^1,2,3), Mitsuko Hayashi-Nishino¹⁾ and Akihito Yamaguchi^2,3)

¹⁾Laboratory of Microbiology and Infectious Diseases, Division of Special Projects, Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka, Japan
²⁾Department of Cell Membrane Biology, Institute of Scientific and Industrial Research, Osaka University
³⁾Department of Cell Biology, Graduate School of Pharmaceutical Sciences, Osaka University
⁴⁾PRESTO, Japan Science and Technology Agency

Abstract

Bacteria have developed regulatory systems for eliciting a variety of adaptive responses to their environments. A number of 40-400 nucleotide RNAs, that do not encode proteins or function as tRNAs or rRNAs have been characterized in prokaryotic organisms. Because of their small sizes, these RNAs generally have been referred to as small RNAs in bacteria. More generally, these RNAs have been termed noncoding RNAs(ncRNAs). Small RNAs made from the opposite strand from their targets and therefore able to basepair extensively with their target mRNA have been described and studied as regulators of plasmid and phage functions for many years. More recent recognition of the importance of trans-acting small RNAs in regulation of bacterial gene expression, including genes involved in bacterial pathogenesis, has extended interest in these molecules, and has led to genome-wide searches for these small RNAs in Escherichia coli. Recent studies have led to the identification of nearly 80 small RNAs in E. coli. However, only a subset of these RNAs has been characterized. It was reported that several small RNAs from E. coli coordinate stress responses and virulence factors. Despite the study of small RNAs in the bacterial regulatory network, their role in drug resistance has remained elusive. In this review article, we introduce the multidrug resistance mechanisms modulated by bacterial small RNAs.

Key word

drug efflux system, multidrug resistance, small RNA

Received

November 30, 2010

Accepted

December 8, 2010

Jpn. J. Chemother. 59 (1): 1-7, 2011