Modulation of cAMP levels by a conserved actinobacteria phosphodiesterase enzyme reduces antimicrobial tolerance in mycobacteria
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PROVIDER: PRJNA660032 | ENA |
REPOSITORIES: ENA
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Project description:The second messenger, cyclic-AMP (cAMP) is conserved across all taxa of life. It is involved in propagating the signal from environmental stimuli and converting it into a response. In bacteria such as M. tuberculosis (Mtb), P. aeruginosa, V. cholerae and B. pertussis, cAMP has been implicated in virulence, regulation of metabolism and gene expression. Cyclic AMP signalling in mycobacteria is especially complex – with 16 enzymes that produce cAMP in Mtb alone. By discovery of a novel, actinobacteria conserved enzyme that degrades cAMP, we have developed a tool to modulate cAMP levels in mycobacteria. By using a combination of metabolomics, bioenergetics and time-to-kill assays, we show that when this enzyme is overexpressed in the model organism M. smegmatis, there is a 3.3 -fold decrease in intracellular cAMP levels. This was concomitant with altered cell envelope permeability, compromised bioenergetics and most importantly, led to a decrease in the tolerance to various frontline antimicrobials. Taken together, this work provides clear evidence that cAMP is involved in antimicrobial tolerance in mycobacteria and that this may represent a promising new target for antimicrobial development.
2022-06-11 | GSE157084 | GEO
Project description:The Rv0805 gene in Mycobacterium tuberculosis encodes a metallophosphoesterase which shows cAMP-hydrolytic activity. Overexpression of Rv0805 has been used as a tool to lower intracellular cAMP levels and thereby elucidate the roles of cAMP in mycobacteria. Here we show that levels of cAMP in M. tuberculosis were lowered by only .30% following overexpression of Rv0805, and transcript levels of a number of genes, which include those associated with virulence and the methyl citrate cycle, were altered. The genes that showed altered expression were distinct from those differentially regulated in a strain deleted for the cAMP-receptor protein (CRP(Mt)), consistent with the relatively low dependence on cAMP of CRP(Mt) binding to DNA. Using mutants of Rv0805 we show that the transcriptional signature of Rv0805 overexpression is a combination of catalysis-dependent and independent effects, and that the structurally flexible C-terminus of Rv0805 is crucial for the catalysis-independent effects of the protein. Our study demonstrates the dissociation of Rv0805 and cAMP-regulated gene expression, and reveals alternate functions for this phosphodiesterase from M. tuberculosis. [Data is also available from http://bugs.sgul.ac.uk/E-BUGS-146]
2013-11-02 | E-BUGS-146 | biostudies-arrayexpress
Project description:Cyclic nucleotide signalling is a major regulator of malaria parasite differentiation. Specific phosphodiesterase (PDE) enzymes are known to control cGMP levels in the parasite, but the mechanisms by with cAMP is regulated remain enigmatic. Here we show that P. falciparum PDEbeta translocates via the ER to an apical location and finally to the plasma membrane of merozoites within the segmented schizont. PDEbeta is essential for blood stage replication, with conditional gene disruption causing a profound invasion phenotype and rapid death of those merozoites that are able to invade a host erythrocyte. Importantly we also demonstrate that PDEbeta is able to hydrolyse both cAMP and cGMP. Loss of PDEbeta activity results in significantly elevated levels of cAMP which correlate temporally with the observed reduction in merozoite invasion. Quantitative phosphoproteomic analysis revealed a >2-fold increase in phosphorylation for >250 phosphosites following silencing of PfPDEbeta. These included a highly significant increase in phosphorylation at PKA substrate consensus sequences. Our results suggest that dysregulated phosphorylation of MyoA S19 and AMA1 S610 likely contributes to the PfPDEbeta knockout invasion phenotype, that PKG activity governs cAMP levels and PKA activation prior to merozoite egress, and that PfPDEbeta has an essential function in regulation cAMP levels in early intra-erythrocytic development in P. falciparum.
2019-02-27 | PXD009157 | Pride
Project description:Acrodysostosis represents a group of rare genetic disorders characterized by defective skeletal development and is often accompanied by intellectual disabilities. Mutations in the 3’5’cyclic AMP (cAMP)-dependent Protein Kinase (PKA) type I regulatory subunit isoform α (RIα) and phosphodiesterase (PDE) PDE4D have both been implicated in impaired PKA regulation in Acrodysostosis. How mutations on PDEs and RIα interfere with regulation of cAMP-PKA signaling is not understood. cAMP-PKA signaling can be described in two phases. In the activation phase, cAMP binding to RIα dissociates the free C-subunit. PDEs hydrolyze cAMP bound to RIα, priming the cAMP-free RIα for reassociation with the C-subunit, thereby completing one PKA activation cycle. Signal termination is thus critical for resetting PKA to its basal state and promoting adaptation to hormonal hyperstimulation. This proceeds through formation of a transient signal termination RIα:PDE complex that facilitates cAMP channeling from the cAMP-binding domain of RIα to the catalytic site of PDE. Signal termination of cAMP-PKA proceeds in three steps: Step 1) Channeling: Translocation of cAMP from the CNB of RIα to the PDE catalytic site for hydrolysis Step 2) Processivity: Binding of free cAMP from the cytosol at both CNBs of RIα and Step 3) Product (5’AMP) release from the PDE hydrolysis site through competitive displacement by a new molecule of cAMP that trigger subsequent activation cycles of PKA. We have identified the molecular basis for two acrodysostosis mutants, (PDE8 T690P) and RIα (T207A) that both allosterically impair cAMP-PKA signal termination. A combination of amide hydrogen/deuterium exchange mass spectrometry (HDXMS) and Fluorescence Polarization (FP) reveal that PDE8 T690P and RIα T207A both blocked processive hydrolysis of cAMP by interfering with competitive displacement of product 5’AMP release from the nucleotide channel at the end of each round of cAMP hydrolysis. While T690P blocked product 5’AMP release from the PDE, T207A greatly slowed release of substrate from RIα. These results highlight the role of processivity in cAMP hydrolysis by RIα:PDE termination complexes for adaptation to cAMP from GPCR hyperstimulation. Impairment of the signal termination process provides an alternate molecular basis for acrodysostosis.
2023-09-13 | PXD045088 | Pride
Project description:This data provides evidence that elevation of cAMP levels has a dramatic effect on the transcriptome of yeast cells, with particular emphasis on mitochondrial function and the promotion of ROS production S. cerevisiae cells lacking the high affinity phosphodiesterase PDE2or both PDE2 and the PKA subunit TPK3 were grown for 24h in rich media in the presence of 4mM exogensously added cAMP. 8 samples.
2010-11-24 | E-GEOD-25541 | biostudies-arrayexpress
Project description:We used transcription-profiling to identify mitogen-activated protein kinase (Mapk) signaling as an important regulator involved in the differentiation of oligodendrocyte progenitor cells (OPCs) into oligodendrocytes. We show in tissue culture that activation of Mapk signaling by elevation of intracellular levels of cAMP using administration of either dibutyryl-cAMP or inhibitors of the cAMP-hydrolyzing enzyme phosphodiesterase-4 (Pde4) enhances OPC differentiation. Finally, we demonstrate that systemic delivery of a Pde4 inhibitor leads to enhanced differentiation of OPCs within focal areas of toxin-induced demyelination and a consequent acceleration of remyelination.
2013-08-29 | GSE50042 | GEO
Project description:Nontuberculous mycobacteria Metagenome
| PRJNA779755 | ENA