Identification of Serine/Threonine Kinase Substrates in the Human Pathogen Group B Streptococcus
- 23 March 2009
- journal article
- research article
- Published by American Chemical Society (ACS) in Journal of Proteome Research
- Vol. 8 (5), 2563-2574
- https://doi.org/10.1021/pr900069n
Abstract
All living organisms respond to changes in their internal and external environment for their survival and existence. Signaling is primarily achieved through reversible phosphorylation of proteins in both prokaryotes and eukaryotes. A change in the phosphorylation state of a protein alters its function to enable the control of cellular responses. A number of serine/threonine kinases regulate the cellular responses of eukaryotes. Although common in eukaryotes, serine/threonine kinases have only recently been identified in prokaryotes. We have described that the human pathogen Group B Streptococcus (GBS, Streptococcus agalactiae) encodes a single membrane-associated, serine/threonine kinase (Stk1) that is important for virulence of this bacterium. In this study, we used a combination of phosphopeptide enrichment and mass spectrometry to enrich and identify serine (S) and threonine (T) phosphopeptides of GBS. A comparison of S/T phosphopeptides identified from the Stk1 expressing strains to the isogenic stk1 mutant indicates that 10 proteins are potential substrates of the GBS Stk1 enzyme. Some of these proteins are phosphorylated by Stk1 in vitro and a site-directed substitution of the phosphorylated threonine to an alanine abolished phosphorylation of an Stk1 substrate. Collectively, these studies provide a novel approach to identify serine/threonine kinase substrates for insight into their signaling in human pathogens like GBS.Keywords
This publication has 64 references indexed in Scilit:
- Threonine phosphorylation prevents promoter DNA binding of the Group B Streptococcus response regulator CovRMolecular Microbiology, 2009
- The Intracellular Concentration of Acetyl Phosphate in Escherichia coli Is Sufficient for Direct Phosphorylation of Two-Component Response RegulatorsJournal of Bacteriology, 2007
- A eukaryotic-type Ser/Thr kinase in Enterococcus faecalis mediates antimicrobial resistance and intestinal persistenceProceedings of the National Academy of Sciences of the United States of America, 2007
- Streptococcus pneumoniaeDivIVA: Localization and Interactions in a MinCD-Free ContextJournal of Bacteriology, 2007
- Regulation of cytotoxin expression by converging eukaryotic‐type and two‐component signalling mechanisms in Streptococcus agalactiaeMolecular Microbiology, 2006
- Identification and Biochemical Characterization of a Eukaryotic-type Serine/Threonine Kinase and its Cognate Phosphatase in Streptococcus pyogenes: Their Biological Functions and Substrate IdentificationJournal of Molecular Biology, 2006
- Analysis of the Phosphoproteome of Chlamydomonas reinhardtii Provides New Insights into Various Cellular PathwaysEukaryotic Cell, 2006
- Phosphoproteome AnalysisBioscience Reports, 2005
- A Large Family of Eukaryotic-Like Protein Ser/Thr Kinases ofMyxococcus xanthus, a Developmental BacteriumMicrobial & Comparative Genomics, 2000
- Two-Component Signal TransductionAnnual Review of Biochemistry, 2000