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

Content Provider	Semantic Scholar
Author	Claywell, Ja E. Fisher, Derek J.
Copyright Year	2016
Abstract	UNLABELLED 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 MnCl2-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 MnCl2 or MgCl2, 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 IMPORTANCE Chlamydia 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.
Starting Page	1827
Ending Page	1836
Page Count	10
File Format	PDF HTM / HTML
Alternate Webpage(s)	http://jb.asm.org/content/198/13/1827.full.pdf
PubMed reference number	27114464v1
Alternate Webpage(s)	https://doi.org/10.1128/JB.00025-16
DOI	10.1128/jb.00025-16
Journal	Journal of bacteriology
Volume Number	198
Issue Number	13
Language	English
Access Restriction	Open
Subject Keyword	Bacterial Physiological Phenomena Chlamydia trachomatis Crk-Associated Substrate Protein Dns-NH2-VVTGVKTGVKTVT-CO2H Magnesium Chloride Maltose Maltose-Binding Proteins Mutation PP1 Antibody Phosphopeptides Phosphoproteins Phosphoric Monoester Hydrolases Phosphoserine Protein Kinases Protein Phosphatase 2A Protein dephosphorylation Protein phosphorylation Substrate Specificity Threonine Tyrosine Virulence Whole-Body Irradiation inorganic phosphate manganese chloride phosphoric monoester hydrolase activity physiological aspects
Content Type	Text
Resource Type	Article