Oomycetes (fungus‐like organisms), brown algae and mammalian parasites as Plasmodium falciparum and fungi can be biotrophic, necrotrophic, or hemibiotrophic plant pathogens

TLS Online TPP Program

#Id: 9085

#Unit 4. Cell Communication and Cell Signaling

Subunit B recognizes and binds to specific gangliosides on the surface of intestinal epithelial cells and provides a route for subunit A to enter. 

TLS Online TPP Program

#Id: 9086

#Unit 4. Cell Communication and Cell Signaling

A1 associates with ARF6, a small G protein in host cells which are accessible only when ARF6 is in its active (GTP-bound) form. 

TLS Online TPP Program

#Id: 9087

#Unit 4. Cell Communication and Cell Signaling

Association with ARF6 activates A1, which catalyzes the transfer of ADP-ribose from NAD to the critical Arg residue in the P loop of the  subunit of Gαs. 

TLS Online TPP Program

#Id: 9088

#Unit 4. Cell Communication and Cell Signaling

TLS Online TPP Program

#Id: 9089

#Unit 4. Cell Communication and Cell Signaling

ADP-ribosylation blocks the GTPase activity of Gαs and renders Gαs permanently active. 

TLS Online TPP Program

#Id: 9090

#Unit 4. Cell Communication and Cell Signaling

This results in continuous activation of the AC of intestinal epithelial cells, chronically active PKA which phosphorylates the CFTR Cl- channel and a Na-H exchanger in the intestinal epithelial cells.