Yehia Daaka

TL;DR: Data suggest that beta-arrestin binding, which terminates receptor-G protein coupling, also initiates a second wave of signal transduction in which the "desensitized" receptor functions as a critical structural component of a mitogenic signaling complex.

TL;DR: A mechanism previously shown to mediate uncoupling of the β2-adrenergic receptor from Gs and thus heterologous desensitization (PKA-mediated receptor phosphorylation), also serves to ‘switch’ coupling of this receptor fromGs to Gi and initiate a new set of signalling events.

TL;DR: Three types of scaffolds for GPCR-directed complex assembly have been identified: transactivated receptor tyrosine kinases, integrin-based focal adhesions, and GPCRs themselves, and nonreceptor tyrosines play an important role in each case.

TL;DR: These paradigms are inadequate to account for GPCR-mediated, Ras-dependent activation of the mitogen-activated protein (MAP) kinases Erk1 and -2, and β2-adrenergic receptor-mediated activation of MAP kinase is inhibited in HEK293 cells expressing dominant suppressor mutants of β-arrestin or dynamin.

TL;DR: Results indicate that calcium-calmodulin plays a central role in the calcium-dependent regulation of tyrosine phosphorylation by G protein-coupled receptors in some systems, and indicate that in HEK-293 cells, the Gβγ subunit-mediated α2A-AR- and the Gαq/11-mediated βARK1ct-mediated Erk1/2 activation pathways converge at the level of phospholipase C.