Question

Pseudomas aeruginosa Exos effector toxin has a ADP ribosylation and GAP function. In its gap function, it acts as a Rho GAP for Rho, Rac, Cdc42 (What are the substrates for these three things) and how does the pathogen's gap function allow it to evade the immune response?

Answer 1

Auswer - The Rho proteins forms a family of G-proteins, that mainly takes part in regulating actin dyanamies and other ey to steeletal actively Rac member of the Rho faemily Gr proteins. Helps in the translocation of GLUT-4 for glucose uptalle. CDC-42 activated ede 42 activates pool activated kinase Pau a and PAKO which initiate action reorganization and regula sulate cell adhesion, migration and invasion. The GAP activity of the pathogen is antiphagocytotic and affects lames podium und membrane ruffle and association association with the formation, in inactivation of a Rac 1. The pathogen the controls the Rho family of proteens through the Gi activity ; as Rho family Gitpases are used for phagocytosis

2 different teppes of phagocytosis k are there - Type 1 sequeres Rac1 and Cdc42 . and is mediated by the re gamma membolled an receptor dhe te gamma - Type 2 requires Rho and is mediated by complement receptor type. 3. son by the GAP activity of the Exos toxin To from Pseudomonas aeroginosa, the Rho family GetPase along with its members involved in phagocytosis are controlled and made inactive by a strogen and hence able to euade a major host defence mechanism - Moreover the activity of cytoskeleton effected is highly cohich the due to effector cells could not be uibed to the pathogen site. cells mmeere aftected are even and and ence mee pathogen the of the immune effector cello so proliferation In fact the cell cytoskeleton due to the effect on dynamies,

The low intrinsic GTP hydrolysis and GDP exchange reactions of G proteins are modulated by (GTPase activating protein) GAPs and Guanine nucleotide exchange factors (GEFs), respectively. Many bacterial toxins have been found to modify the function of GTP binding proteins and, in turn, affect signal transduction in eukaryotic cells.