Rebecca L Eccles, Maciej T Czajkowski, Carolin Barth, Paul Markus Müller, Erik McShane, Stephan Grunwald, Patrick Beaudette, Nora Mecklenburg, Rudolf Volkmer, Kerstin Zühlke, Gunnar Dittmar, Matthias Selbach, Annette Hammes, Oliver Daumke, Enno Klussmann, Sylvie Urbé, Oliver Rocks
Protein kinase A is a key mediator of cAMP signalling downstream of G-protein-coupled receptors, a signalling pathway conserved in all eukaryotes. cAMP binding to the regulatory subunits (PKAR) relieves their inhibition of the catalytic subunits (PKAC). Here we report that ARHGAP36 combines two distinct inhibitory mechanisms to antagonise PKA signalling. First, it blocks PKAC activity via a pseudosubstrate motif, akin to the mechanism employed by the protein kinase inhibitor proteins. Second, it targets PKAC for rapid ubiquitin-mediated lysosomal degradation, a pathway usually reserved for transmembrane receptors...
October 7, 2016: Nature Communications