Expression and Genetic Activation of Cyclic Di-GMP-Specific Phosphodiesterases in Escherichia coli

التفاصيل البيبلوغرافية
العنوان: Expression and Genetic Activation of Cyclic Di-GMP-Specific Phosphodiesterases in Escherichia coli
المؤلفون: Urs Jenal, Shogo Ozaki, Alberto Reinders, Chee Seng Hee, Alex Boehm, Adam Mazur, Tilman Schirmer
المصدر: Journal of Bacteriology
سنة النشر: 2016
مصطلحات موضوعية: 0301 basic medicine, Cyclic di-GMP, Movement, 030106 microbiology, Video Recording, Biology, medicine.disease_cause, Microbiology, Gene Expression Regulation, Enzymologic, 03 medical and health sciences, chemistry.chemical_compound, Transcription (biology), Catalytic Domain, Escherichia coli, medicine, Transcriptional regulation, Amino Acid Sequence, Cyclic GMP, Molecular Biology, Transcription factor, Gene, Phosphoric Diester Hydrolases, Escherichia coli Proteins, Phosphodiesterase, Gene Expression Regulation, Bacterial, Articles, chemistry, Biochemistry, Second messenger system
الوصف: Intracellular levels of the bacterial second messenger cyclic di-GMP (c-di-GMP) are controlled by antagonistic activities of diguanylate cyclases and phosphodiesterases. The phosphodiesterase PdeH was identified as a key regulator of motility in Escherichia coli , while deletions of any of the other 12 genes encoding potential phosphodiesterases did not interfere with motility. To analyze the roles of E. coli phosphodiesterases, we demonstrated that most of these proteins are expressed under laboratory conditions. We next isolated suppressor mutations in six phosphodiesterase genes, which reinstate motility in the absence of PdeH by reducing cellular levels of c-di-GMP. Expression of all mutant alleles also led to a reduction of biofilm formation. Thus, all of these proteins are bona fide phosphodiesterases that are capable of interfering with different c-di-GMP-responsive output systems by affecting the global c-di-GMP pool. This argues that E. coli possesses several phosphodiesterases that are inactive under laboratory conditions because they lack appropriate input signals. Finally, one of these phosphodiesterases, PdeL, was studied in more detail. We demonstrated that this protein acts as a transcription factor to control its own expression. Motile suppressor alleles led to a strong increase of PdeL activity and elevated pdeL transcription, suggesting that enzymatic activity and transcriptional control are coupled. In agreement with this, we showed that overall cellular levels of c-di-GMP control pdeL transcription and that this control depends on PdeL itself. We thus propose that PdeL acts both as an enzyme and as a c-di-GMP sensor to couple transcriptional activity to the c-di-GMP status of the cell. IMPORTANCE Most bacteria possess multiple diguanylate cyclases and phosphodiesterases. Genetic studies have proposed that these enzymes show signaling specificity by contributing to distinct cellular processes without much cross talk. Thus, spatial separation of individual c-di-GMP signaling units was postulated. However, since most cyclases and phosphodiesterases harbor N-terminal signal input domains, it is equally possible that most of these enzymes lack their activating signals under laboratory conditions, thereby simulating signaling specificity on a genetic level. We demonstrate that a subset of E. coli phosphodiesterases can be activated genetically to affect the global c-di-GMP pool and thus influence different c-di-GMP-dependent processes. Although this does not exclude spatial confinement of individual phosphodiesterases, this study emphasizes the importance of environmental signals for activation of phosphodiesterases.
DOI: 10.1128/JB.00604-15
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::bf72d29042d99dc74e20a22e25526c34
Rights: OPEN
رقم الانضمام: edsair.doi.dedup.....bf72d29042d99dc74e20a22e25526c34
قاعدة البيانات: OpenAIRE