title: Cyclic di-GMP activation of polynucleotide phosphorylase signal-dependent RNA processing.
abstract: The second messenger cyclic diguanylic acid (c-di-GMP) is implicated in key lifestyle decisions of bacteria, including biofilm formation and changes in motility and virulence. Some challenges in deciphering the physiological roles of c-di-GMP are the limited knowledge about the cellular targets of c-di-GMP, the signals that control its levels, and the proportion of free cellular c-di-GMP, if any. Here, we identify the target and the regulatory signal for a c-di-GMP-responsive Escherichia coli ribonucleoprotein complex. We show that a direct c-di-GMP target in E. coli is polynucleotide phosphorylase (PNPase), an important enzyme in RNA metabolism that serves as a 3' polyribonucleotide polymerase or a 3'-to-5' exoribonuclease. We further show that a complex of polynucleotide phosphorylase with the direct oxygen sensors DosC and DosP can perform oxygen-dependent RNA processing. We conclude that c-di-GMP can mediate signal-dependent RNA processing and that macromolecular complexes can compartmentalize c-di-GMP signaling.
authors.affiliation: Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas,TX 75390-9038, USA.
authors.forename: Jason R
authors.initials: JR
authors.lastname: Tuckerman
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Gonzalez
authors.forename: Marie-Alda
authors.initials: MA
authors.lastname: Gilles-Gonzalez
mesh_terms: D006152:Cyclic GMP / Q000031:analogs & derivatives* / Q000378:metabolism; D004722:Endoribonucleases / Q000378:metabolism; D004789:Enzyme Activation; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D006418:Heme / Q000378:metabolism; D046911:Macromolecular Substances; D010100:Oxygen / Q000378:metabolism; D010751:Phosphopyruvate Hydratase / Q000378:metabolism; D011117:Polyribonucleotide Nucleotidyltransferase / Q000378:metabolism*; D012313:RNA / Q000235:genetics / Q000378:metabolism*; D015290:Second Messenger Systems / Q000502:physiology*
chemical_list: D029968:Escherichia coli Proteins; D046911:Macromolecular Substances; D006418:Heme; C062025:bis(3',5')-cyclic diguanylic acid; D012313:RNA; D011117:Polyribonucleotide Nucleotidyltransferase; D004722:Endoribonucleases; C022537:ribonuclease E; D010751:Phosphopyruvate Hydratase; D006152:Cyclic GMP; D010100:Oxygen