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. 

TLS Online TPP Program

#Id: 9091

#Unit 4. Cell Communication and Cell Signaling

The resultant efflux of NaCl triggers massive water loss through the intestine as cells respond to the ensuing osmotic imbalance causes severe dehydration and electrolyte loss.

TLS Online TPP Program

#Id: 9092

#Unit 4. Cell Communication and Cell Signaling

Pertussis toxin, produced by Bordetella pertussis, catalyzes ADP-ribosylation of the  subunit of Gαi, preventing GDP-GTP exchange and blocking inhibition of adenylyl cyclase.

TLS Online TPP Program

#Id: 9093

#Unit 4. Cell Communication and Cell Signaling

Ligand binding to GPCRs that activate Gαq, leading to activation of phospholipase C

TLS Online TPP Program

#Id: 9094

#Unit 4. Cell Communication and Cell Signaling

Phospholipase C cleaves a phospholipid known as PI(4,5) P2, generating two second messengers: 

diffusible IP3 and membrane-bound DAG