Abstract
Tyrosine phosphorylation modifies the functionality of bacterial proteins and forms the basis of a versatile and tunable signal transduction system. The integrated action of tyrosine kinases and phosphatases controls bacterial processes important for metabolism and virulence. Porphyromonas gingivalis, a keystone pathogen in periodontal disease, possesses an extensive phosphotyrosine signaling network. The phosphorylation reaction is catalyzed by a bacterial tyrosine (BY) kinase, Ptk1, and a Ubiquitous bacterial Kinase UbK1. Dephosphorylation is mediated by a low-molecular-weight phosphatase, Ltp1 and a polymerase and histidinol phosphatase, Php1. Phosphotyrosine signaling controls exopolysaccharide production, gingipain activity, oxidative stress responses and synergistic community development with Streptococcus gordonii. Additionally, Ltp1 is secreted extracellularly and can be delivered inside gingival epithelial cells where it can override host cell signaling and readjust cellular physiology. The landscape of coordinated tyrosine kinase and phosphatase activity thus underlies the adaptive responses of P. gingivalis to both the polymicrobial environment of bacterial communities and the intracellular environment of gingival epithelial cells.
Highlights
GENERAL FEATURES OF TYROSINE PHOSPHORYLATION IN BACTERIASignal transduction mediated by coordinated and reversible protein phosphorylation events regulates a wide variety of biological processes in all living cells
Phosphodependent signaling can occur through two component systems (TCS) which rely on His/Asp phosphorylation, as well as through phosphorylation of Ser/Thr or of Tyr residues [1, 2]
Tyrosine phosphorylation is catalyzed by distinct types of residue-specific kinases and is reversed by cognate phosphatases
Summary
Signal transduction mediated by coordinated and reversible protein phosphorylation events regulates a wide variety of biological processes in all living cells. Tyrosine phosphorylation is catalyzed by distinct types of residue-specific kinases and is reversed by cognate phosphatases. The Bacterial Tyrosine (BY) kinases are the most extensively studied tyrosine-phosphorylating enzyme [2, 4]. There are three major families of tyrosine phosphatases which dephosphorylate and thereby inactivate BY kinases: low-molecular-weight phosphatases (LMW-PTPs), small acidic enzymes found in eukaryotes; the eukaryotic-like phosphatases (PTPs), dual-specific phosphatases that display activity against phosphoserine and phosphothreonine; and the DNA polymerase and histidinol phosphate phosphoesterase (PHP) family [2]. As bacterial kinases and phosphatases are active on eukaryotic substrates, many pathogenic bacteria weaponize these enzymes to manipulate signaling in host cells and promote survival in the hosts. The action of tyrosine kinases and phosphatases, is a key regulatory node that can underlie bacterial pathogenesis in a context- and species- dependent manner
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
