You've come a long way: c-di-GMP signaling

Abstract

Cyclic dimeric guanosine monophosphate (c-di-GMP) is a common, bacterial second messenger that regulates diverse cellular processes in bacteria. Opposing activities of diguanylate cyclases (DGCs) and phosphodiesterases (PDEs) control c-di-GMP homeostasis in the cell. Many microbes have a large number of genes encoding DGCs and PDEs that are predicted to be part of c-di-GMP signaling networks. Other building blocks of these networks are c-di-GMP receptors which sense the cellular levels of the dinucleotide. C-di-GMP receptors form a more diverse family, including various transcription factors, PilZ domains, degenerate DGCs or PDEs, and riboswitches. Recent studies revealing the molecular basis of c-di-GMP signaling mechanisms enhanced our understanding of how this molecule controls downstream biological processes and how c-di-GMP signaling specificity is achieved.

Figure 1

c-di-GMP is a common, bacterial second messenger that controls the transition from a free-living, motile lifestyle to a biofilm one. c-di-GMP is produced by DGC proteins containing the GGDEF domain and degraded by PDE proteins bearing the EAL or HD-GYP domains. c-diGMP is sensed by receptor proteins or RNAs from either the PilZ, degenerate GGDEF or EAL domain, transcriptional factors or riboswitch families. Typically, receptor proteins then interact with a downstream target to affect a particular cellular function.