Cyclic di-GMP regulation of gene expression

Abstract

Cyclic di-GMP is a nearly ubiquitous bacterial second messenger signaling molecule that links changes in environmental cues to the regulation of a myriad of phenotypes including but not limited to biofilm formation, motility, virulence, and DNA repair. A complex network of cyclic di-GMP synthesis and degradation enzymes is present in many bacteria, each of which is hypothesized to respond to a different signal that is integrated into changes in cyclic di-GMP levels. Cyclic di-GMP regulates downstream phenotypes via a variety of different mechanisms including control of transcription initiation via direct interaction with transcription factors, binding to RNA riboswitches to control gene expression posttranscriptionally, or direct interaction with enzymes or protein complexes to allosterically regulate their activity. In this chapter, we will review what is known about cyclic di-GMP regulation of gene expression, both transcriptionally and post-transcriptionally, focusing on transcription factors and riboswitches that directly bind to cyclic di-GMP.