Tlr0485 is a cAMP-activated c-di-GMP phosphodiesterase in a cyanobacterium Thermosynechococcus

J Gen Appl Microbiol. 2020 Jun 17;66(2):147-152. doi: 10.2323/jgam.2020.01.007. Epub 2020 Mar 30.


Second messenger molecules are crucial components of environmental signaling systems to integrate multiple inputs and elicit physiological responses. Among various kinds of second messengers, cyclic nucleotides cAMP and cyclic di-GMP (c-di-GMP) play pivotal roles in bacterial environmental responses. However, how these signaling systems are interconnected for a concerted regulation of cellular physiology remains elusive. In a thermophilic cyanobacterium Thermosynechococcus vulcanus strain RKN, incident light color is sensed by cyanobacteriochrome photoreceptors to transduce the light information to the levels of c-di-GMP, which induces cellular aggregation probably via cellulose synthase activation. Herein, we identified that Tlr0485, which is composed of a cGMP-specific phosphodiesterases, adenylate cyclases, and FhlA (GAF) domain and an HD-GYP domain, is a cAMP-activated c-di-GMP phosphodiesterase. We also show biochemical evidence that the two class-III nucleotide cyclases, Cya1 and Cya2, are both adenylate cyclases to produce cAMP in T. vulcanus. The prevalence of cAMP-activated c-di-GMP phosphodiesterase genes in cyanobacterial genomes suggests that the direct crosstalk between cAMP and c-di-GMP signaling systems may be crucial for cyanobacterial environmental responses.

Keywords: Thermosynechococcus; cAMP; cyanobacteria; cyclic di-GMP; second messenger; sessility; signal transduction.

MeSH terms

  • 3',5'-Cyclic-GMP Phosphodiesterases / genetics
  • 3',5'-Cyclic-GMP Phosphodiesterases / metabolism*
  • Adenylyl Cyclases / genetics
  • Adenylyl Cyclases / metabolism
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Chromatography, High Pressure Liquid
  • Cyclic AMP / metabolism*
  • Cyclic GMP / analogs & derivatives*
  • Cyclic GMP / metabolism
  • Electrophoresis, Polyacrylamide Gel
  • Mutation
  • Protein Domains
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Second Messenger Systems*
  • Signal Transduction
  • Thermosynechococcus / enzymology
  • Thermosynechococcus / genetics


  • Bacterial Proteins
  • Recombinant Proteins
  • bis(3',5')-cyclic diguanylic acid
  • Cyclic AMP
  • 3',5'-Cyclic-GMP Phosphodiesterases
  • Adenylyl Cyclases
  • Cyclic GMP

Supplementary concepts

  • Thermosynechococcus vulcanus