biostudies-literatureNewell PDNIGMS NIH HHS3461-6https://www.ebi.ac.uk/biostudies/studies/S-EPMC2651287biostudies-literatureUnknown106(9)The second messenger cyclic dimeric GMP (c-di-GMP) regulates surface attachment and biofilm formation by many bacteria. For Pseudomonas fluorescens Pf0-1, c-di-GMP impacts the secretion and localization of the adhesin LapA, which is absolutely required for stable surface attachment and biofilm formation by this bacterium. In this study we characterize LapD, a unique c-di-GMP effector protein that controls biofilm formation by communicating intracellular c-di-GMP levels to the membrane-localized attachment machinery via its periplasmic domain. LapD contains degenerate and enzymatically inactive diguanylate cyclase and c-di-GMP phosphodiesterase (EAL) domains and binds to c-di-GMP through a degenerate EAL domain. We present evidence that LapD utilizes an inside-out signaling mechanism: binding c-di-GMP in the cytoplasm and communicating this signal to the periplasm via its periplasmic domain. Furthermore, we show that LapD serves as the c-di-GMP receptor connecting environmental modulation of intracellular c-di-GMP levels by inorganic phosphate to regulation of LapA localization and thus surface commitment by P. fluorescens.Proceedings of the National Academy of Sciences of the United States of AmericaLapD is a bis-(3',5')-cyclic dimeric GMP-binding protein that regulates surface attachment by Pseudomonas fluorescens Pf0-1.PMC2651287T32 GM008704T32 GM08704O'Toole GANewell PDMonds RDfalseLapD is a bis-(3',5')-cyclic dimeric GMP-binding protein that regulates surface attachment by Pseudomonas fluorescens Pf0-1.The second messenger cyclic dimeric GMP (c-di-GMP) regulates surface attachment and biofilm formation by many bacteria. For Pseudomonas fluorescens Pf0-1, c-di-GMP impacts the secretion and localization of the adhesin LapA, which is absolutely required for stable surface attachment and biofilm formation by this bacterium. In this study we characterize LapD, a unique c-di-GMP effector protein that controls biofilm formation by communicating intracellular c-di-GMP levels to the membrane-localized attachment machinery via its periplasmic domain. LapD contains degenerate and enzymatically inactive diguanylate cyclase and c-di-GMP phosphodiesterase (EAL) domains and binds to c-di-GMP through a degenerate EAL domain. We present evidence that LapD utilizes an inside-out signaling mechanism: binding c-di-GMP in the cytoplasm and communicating this signal to the periplasm via its periplasmic domain. Furthermore, we show that LapD serves as the c-di-GMP receptor connecting environmental modulation of intracellular c-di-GMP levels by inorganic phosphate to regulation of LapA localization and thus surface commitment by P. fluorescens.2009-01-01T00:00:00Z2009 Mar2024-11-21T09:43:51.893Z2019-03-27T00:21:02ZS-EPMC26512871921845110.1073/pnas.0808933106