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 post-transcriptionally, 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.