Protein-serine/threonine/tyrosine kinases in bacterial signaling and regulation
Résumé
In this review, we address some recent developments in the field of bacterial protein phosphorylation, focusing specifically on serine/threonine and tyrosine kinases. We present an overview of recent studies outlining the scope of physiological processes that are regulated by phosphorylation, ranging from cell cycle, growth, cell morphology, to metabolism, developmental phenomena, and virulence. Specific emphasis is placed on Mycobacterium tuberculosis as a showcase organism for serine/threonine kinases, and Bacillus subtilis to illustrate the importance of protein phosphorylation in developmental processes. We argue that bacterial serine/threonine and tyrosine kinases have a distinctive feature of phosphorylating multiple substrates and might thus represent integration nodes in the signaling network. Some open questions regarding the evolutionary benefits of relaxed substrate selectivity of these kinases are treated, as well as the notion of nonfunctional background' phosphorylation of cellular proteins. We also argue that phosphorylation events for which an immediate regulatory effect is not clearly established should not be dismissed as unimportant, as they may have a role in cross-talk with other post-translational modifications. Finally, recently developed methods for studying protein phosphorylation networks in bacteria are briefly discussed.
Mots clés
phosphoproteomics
protein phosphorylation
development
pathogenic bacteria
regulatory network
BACILLUS-SUBTILIS
MYCOBACTERIUM-TUBERCULOSIS
STAPHYLOCOCCUS-AUREUS
TYROSINE KINASE
SER/THR PHOSPHORYLATION
ESCHERICHIA-COLI
ARGININE PHOSPHORYLATION
STREPTOCOCCUS-PNEUMONIAE
PHOSPHOPROTEOME ANALYSIS
CELL-DIVISION