RNA-Mediated Crosstalk Between Bacterial Core Genome and Foreign Genetic Elements

Abstract

Gene expression is regulated at both transcriptional and posttranscriptional levels. Foreign genetic elements have evolved to integrate their expression systems into the host regulatory network. Transcription of AT-rich foreign genes is globally silenced by chromosomal nucleoid proteins such as H-NS. Similarly, a global posttranscriptional regulator Hfq tends to bind AU-rich transcripts and plays an important role to optimize expression of foreign genes as well as its core genome. The RNA chaperone Hfq also facilitates base-pairing between RNA molecules in trans and thus contributes to the crosstalk between chromosomal and foreign genes. Moreover, other classes of RNA chaperones are also involved in the crosstalk. Taking the model pathogen Salmonella Typhimurium as an example, this chapter focuses on the RNA-mediated crosstalk between chromosome and foreign genetic elements.