Ser/Thr phosphorylation as a regulatory mechanism in bacteria

Dworkin, Jonathan

doi:10.1016/j.mib.2015.01.005

Cited by 118 publications

(90 citation statements)

References 60 publications

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“…Proteins phosphorylated in EBs, but not in RBs, included proteins involved in central metabolism (highlighted in Table 2), nucleotide and co-factor metabolism, amino acid metabolism, and virulence (including two T3SS components). We hypothesize that phosphorylation inhibits the activity of the targeted EB proteins, allowing for rapid activation by dephosphorylation upon infection (Dworkin, 2015). Such a mechanism would also alleviate the need for protein synthesis in EBs, as they could be pre-packaged with all the requisite proteins needed for infection.…”

Section: Discussionmentioning

confidence: 99%

Phosphoproteomic analysis of the Chlamydia caviae elementary body and reticulate body forms

2015

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Chlamydia are Gram-negative, obligate intracellular bacteria responsible for significant diseases in humans and economically important domestic animals. These pathogens undergo a unique biphasic developmental cycle transitioning between the environmentally stable elementary body (EB) and the replicative intracellular reticulate body (RB), a conversion that appears to require extensive regulation of protein synthesis and function. However, Chlamydia possess a limited number of canonical mechanisms of transcriptional regulation. Ser/Thr/Tyr phosphorylation of proteins in bacteria has been increasingly recognized as an important mechanism of posttranslational control of protein function. We utilized 2D gel electrophoresis coupled with phosphoprotein staining and MALDI-TOF/TOF analysis to map the phosphoproteome of the EB and RB forms of Chlamydia caviae. Forty-two non-redundant phosphorylated proteins were identified (some proteins were present in multiple locations within the gels). Thirty-four phosphorylated proteins were identified in EBs, including proteins found in central metabolism and protein synthesis, Chlamydia-specific hypothetical proteins and virulence-related proteins. Eleven phosphorylated proteins were identified in RBs, mostly involved in protein synthesis and folding and a single virulence-related protein. Only three phosphoproteins were found in both EB and RB phosphoproteomes. Collectively, 41 of 42 C. caviae phosphoproteins were present across Chlamydia species, consistent with the existence of a conserved chlamydial phosphoproteome. The abundance of stage-specific phosphoproteins suggests that protein phosphorylation may play a role in regulating the function of developmental-stage-specific proteins and/or may function in concert with other factors in directing EB-RB transitions.

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Section: Discussionmentioning

confidence: 99%

Phosphoproteomic analysis of the Chlamydia caviae elementary body and reticulate body forms

2015

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“…With recent developments in mass spectrometry (MS) based phosphoproteomics, it became clear that O-phosphorylation was widely distributed also in the domain Bacteria (16,17).…”

Section: Introductionmentioning

confidence: 99%

Chlorosis as a Developmental Program in Cyanobacteria: The Proteomic Fundament for Survival and Awakening

Spät

Klotz

Rexroth

et al. 2018

Molecular & Cellular Proteomics

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“…Reversible phosphorylation of proteins is a posttranslational regulatory mechanism involved in multiple complex processes, including cell signaling, growth, and differentiation, in both eukaryotes and prokaryotes (9,10). Regulation at the molecular level is mediated by the addition or removal of a phosphate group from select amino acids (typically Ser, Thr, Tyr, His, and Asp) by the opposing actions of protein kinases and their cognate phosphatases serving to modulate the activity, interactions, and localization of target proteins (11,12).…”

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confidence: 99%

CTL0511 from Chlamydia trachomatis Is a Type 2C Protein Phosphatase with Broad Substrate Specificity

Claywell

Fisher

2016

J Bacteriol

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Protein phosphorylation has become increasingly recognized for its role in regulating bacterial physiology and virulence. Chlamydia spp. encode two validated Hanks'-type Ser/Thr protein kinases, which typically function with cognate protein phosphatases and appear capable of global protein phosphorylation. Consequently, we sought to identify a Ser/Thr protein phosphatase partner for the chlamydial kinases. CTL0511 from Chlamydia trachomatis L2 434/Bu, which has homologs in all sequenced Chlamydia spp., is a predicted type 2C Ser/Thr protein phosphatase (PP2C). Recombinant maltose-binding protein (MBP)-tagged CTL0511 (rCTL0511) hydrolyzed p-nitrophenyl phosphate (pNPP), a generic phosphatase substrate, in a MnCl 2 -dependent manner at physiological pH. Assays using phosphopeptide substrates revealed that rCTL0511 can dephosphorylate phosphorylated serine (P-Ser), P-Thr, and P-Tyr residues using either MnCl 2 or MgCl 2 , indicating that metal usage can alter substrate preference. Phosphatase activity was unaffected by PP1, PP2A, and PP3 phosphatase inhibitors, while mutation of conserved PP2C residues significantly inhibited activity. Finally, phosphatase activity was detected in elementary body (EB) and reticulate body (RB) lysates, supporting a role for protein dephosphorylation in chlamydial development. These findings support that CTL0511 is a metal-dependent protein phosphatase with broad substrate specificity, substantiating a reversible phosphorylation network in C. trachomatis. IMPORTANCEChlamydia spp. are obligate intracellular bacterial pathogens responsible for a variety of diseases in humans and economically important animal species. Our work demonstrates that Chlamydia spp. produce a PP2C capable of dephosphorylating P-Thr, P-Ser, and P-Tyr and that Chlamydia trachomatis EBs and RBs possess phosphatase activity. In conjunction with the chlamydial Hanks'-type kinases Pkn1 and PknD, validation of CTL0511 fulfills the enzymatic requirements for a reversible phosphoprotein network. As protein phosphorylation regulates important cellular processes, including metabolism, differentiation, and virulence, in other bacterial pathogens, these results set the stage for elucidating the role of global protein phosphorylation in chlamydial physiology and virulence. C hlamydia spp. are obligate intracellular bacterial pathogens that are widely distributed in nature and are responsible for significant diseases in humans and a variety of animals (1, 2). The human-specific pathogen Chlamydia trachomatis is the leading cause of preventable blindness and the most common reportable bacterial sexually transmitted infection both in the United States and worldwide (3, 4). C. trachomatis infections of the conjunctiva and the urogenital tract may lead to chronic diseases, including trachoma, pelvic inflammatory disease, and infertility (1). Further understanding of the physiology of these highly significant pathogens is critical for developing therapeutics and vaccines.While Chlamydia spp. differ in host range and virul...

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Ser/Thr phosphorylation as a regulatory mechanism in bacteria

Cited by 118 publications

References 60 publications

Phosphoproteomic analysis of the Chlamydia caviae elementary body and reticulate body forms

Phosphoproteomic analysis of the Chlamydia caviae elementary body and reticulate body forms

Chlorosis as a Developmental Program in Cyanobacteria: The Proteomic Fundament for Survival and Awakening

CTL0511 from Chlamydia trachomatis Is a Type 2C Protein Phosphatase with Broad Substrate Specificity

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