The genetic expression from adenoviruses is transient, where the DNA is free within the host cell’s nucleus (episomal) where it can be transcribed, but upon cell division these genes will not be replicated.

TLS Online TPP Program

#Id: 9071

#Unit 4. Cell Communication and Cell Signaling

Feedback mechanisms suppress signaling by the PKA pathway:

1. Intrinsic GTPase activity of Gαs

2. PDE acts to hydrolyze cAMP to 5′-AMP

3. By BARK

TLS Online TPP Program

#Id: 9072

#Unit 4. Cell Communication and Cell Signaling

In resting state 

basal level of PDE activity keeps cAMP levels below those necessary for PKA activation.

TLS Online TPP Program

#Id: 9073

#Unit 4. Cell Communication and Cell Signaling

TLS Online TPP Program

#Id: 9074

#Unit 4. Cell Communication and Cell Signaling

Activation of β-adrenergic receptors causes activation of C subunits of PKA which phosphorylate PDE, stimulating its catalytic activity.

TLS Online TPP Program

#Id: 9075

#Unit 4. Cell Communication and Cell Signaling

Active PDE hydrolyzes cAMP, driving cAMP levels back to basal levels.

TLS Online TPP Program

#Id: 9076

#Unit 4. Cell Communication and Cell Signaling

A G protein– coupled receptor kinase phosphorylates serine and threonine residues in the

cytoplasmic segments of activated GPCRs