Comparative Analysis Of Proteome And Phosphoproteome Change In Response To Temperature Stress In Shigella Flexneri

The causative orgamisms of shigellosis or bacillary dysentery is Shigella spp., the invasion of which is influenced by the temperature. Growing at30℃will make Shigellae avirulent and non-invasion. Nowadays, few experiments focus on the ratlionship among temperature, phosphoproteome and proteome of shigella spp.. This research shows the differential phosphoproteome of Shigella flexneri growing at30℃and37℃.2D-PAGE was applied to separate simultaneous samples. Multiplex preteomics is then applied to show the difference between them. Combining with the MS identification, this research offers the differential phosphoproteome at30℃and37℃.55phosphoproteins have been identified, the function of most of which include translation (24.6%), carbon transport and metabolism (21.1%) and post-translation (10.5%). Phosphorylation of18proteins are up-regulated at30℃. Phosphorylation of10proteins are up-regulated at37℃.6proteins are phosphorated only at30℃and21of them are phosphorated only at37℃.Phosphorylation of EF-Tu is found up-regulated at30℃. As reported, the function of EF-Tu will be attenuated by phosphorylation. Phosphorylation of NDPK is also up-rugulated at30℃, which can reduce the growth of S. flexneri. GAD is found phosphate only at30℃, and the expression is down-regulated simultaneously. The cooperation of phosphoraltaion and low-expression can regulate the function of GAD. PfkB, one of the regulation center of glycolysis, is found phosphorated only at37℃. PfkB is activated by phosphorylation. The phosphorylation and expression level of OmpC and Crr are up-regulated at37℃, strengthening the function of them.Type III secretion system (T3SS) and pathogenic islands (PAIs) are important virulence factors of Shigella spp.. GAD and OmpC are regulated to adapt the host environment (temperature, low pH, osmotic pression) through infection. PhoP is also phosphorated through invasion. EF-Tu, DnaK and PNP, which have be identified in this experiment, are recognized as potential effectors of T3SS, too.The expression and modification of proteins in bacteria is a dynamic procession. This research shows a brief frame of differential phosphoproteomics, which needs detailed studies.