CAMP-GEFs

In the cAMP-bound conformation, cAMP-GEFs specifically bind to Ras-like small GTPases and activate these proteins by profoundly accelerating the exchange of GDP for GTP. 

Regulation of Adenylate Cyclase and Neurotransmitter Release -PKA-Independent Regulation by cAMP Through HCN Channels and cAMP-GEF... 

Following the identification of cAMP-GEFs as cAMP-binding proteins that activate the small G-protein Rapl (De Rooij et al. 1998 Kawasaki et al. 1998), a role... 

DAG can also affect release independently of PKC activation, through an interaction with Muncl3. cAMP also has non-PKA-mediated actions (e.g., on hyperpolarization-activated cation channels and cAMP-GEFs), which affect release. 

Regulation of the GEFs is very diverse and does not only include adaptor-mediated interactions with the activated receptor. There are other Ras-GEFs that are controlled by distinctly different mechanisms, namely via second messengers. Ras-GEFs have been identified in brain that are subject to control by diacylglycerol and Ca (see 9.7). In addition, an exchange factor activated by cAMP has been described for Rapl protein (see 9.6.2) (Roij et al., 1998). 

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