title: Protein-tyrosine phosphorylation in Bacillus subtilis: a 10-year retrospective.
abstract: The discovery of tyrosine-phosphorylated proteins in Bacillus subtilis in the year 2003 was followed by a decade of intensive research activity. Here we provide an overview of the lessons learned in that period. While the number of characterized kinases and phosphatases involved in reversible protein-tyrosine phosphorylation in B. subtilis has remained essentially unchanged, the number of proteins known to be targeted by this post-translational modification has increased dramatically. This is mainly due to phosphoproteomics and interactomics studies, which were instrumental in identifying new tyrosine-phosphorylated proteins. Despite their structural similarity, the two B. subtilis protein-tyrosine kinases (BY-kinases), PtkA and PtkB (EpsB), seem to accomplish different functions in the cell. The PtkB is encoded by a large operon involved in exopolysaccharide production, and its main role appears to be the control of this process. The PtkA seems to have a more complex role; it phosphorylates and regulates a large number of proteins involved in the DNA, fatty acid and carbon metabolism and engages in physical interaction with other types of kinases (Ser/Thr kinases), leading to mutual phosphorylation. PtkA also seems to respond to several activator proteins, which direct its activity toward different substrates. In that respect PtkA seems to function as a highly connected signal integration device.
authors: Systems and Synthetic Biology, Department of Chemical and Biological Engineering, Chalmers University of Technology , Göteborg, Sweden.
authors: Ivan
authors: I
authors: Mijakovic
authors: Centre National de la Recherche Scientifique, FRE3630 Expression Génétique Microbienne, Institut de Biologie Physico-Chimique , Paris, France ; UMR1319 Microbiologie de l'Alimentation au Service de la Santé Humaine, Institut National de la Recherche Agronomique/AgroParisTech , Jouy en Josas, France.
authors: Josef
authors: J
authors: Deutscher
keywords: BY-kinase; phosphotyrosine-protein phosphatase; protein phosphorylation; regulatory network; substrate specificity