Janet D. Robishaw

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Membranes from bovine brain bind relatively large quantities of guanosine 5'-(3-O-thio)triphosphate (GTP gamma S) with high affinity. The two proteins responsible for most of this activity were purified; they account for 1.5% of the membrane protein. The two proteins contain alpha subunits of either 39,000 or 41,000 Da, beta subunits of 36,000 or 35,000 Da,(More)
Heterotrimeric G-proteins are components of the signal transduction pathways for the soluble and cell-contact signals that regulate normal growth and differentiation. There is now a greater appreciation of the role of the Gβγ-dimer in the regulation of a variety of intracellular effectors, including ion channels, adenylyl cyclase, and phospholipase Cβ. In(More)
The metabolism of coenzyme A and control of its synthesis are reviewed. Pantothenate kinase is an important rate-controlling enzyme in the synthetic pathway of all tissues studied and appears to catalyze the flux-generating reaction of the pathway in cardiac muscle. This enzyme is strongly inhibited by coenzyme A and all of its acyl esters. The cytosolic(More)
Gpr161 (also known as RE2) is an orphan G protein-coupled receptor (GPCR) that is expressed during embryonic development in zebrafish. Determining its biological function has proven difficult due to lack of knowledge regarding its natural or synthetic ligands. Here, we show that targeted knockdown of gpr161 disrupts asymmetric gene expression in the lateral(More)
Activation of alpha(1)-adrenergic receptors influences both the contractile activity and the growth potential of cardiac myocytes. However, the signaling pathways linking activation of specific alpha(1)-adrenergic receptor (AR) subtypes to these physiological responses remain controversial. In the present study, a molecular approach was used to identify(More)
The G protein-coupled receptor (GPCR) kinases (GRKs) phosphorylate and desensitize agonist-occupied GPCRs. GRK2-mediated receptor phosphorylation is preceded by the agonist-dependent membrane association of this enzyme. Previous in vitro studies with purified proteins have suggested that this translocation may be mediated by the recruitment of GRK2 to the(More)
Guanine nucleotide-binding proteins (G proteins) involved in transmembrane signal-transduction processes are heterotrimers composed of alpha, beta, and gamma subunits. The alpha subunit shows great diversity and is thought to confer functional specificity to a particular G protein. By contrast, the beta and gamma subunits appear much less diverse; in(More)
The adenosine A(2A) receptor (A(2A)R) is increasingly recognized as a novel therapeutic target in Parkinson disease. In striatopallidal neurons, the G-protein α(olf) subtype is required to couple this receptor to adenylyl cyclase activation. It is now well established that the βγ dimer also performs an active role in this signal transduction process. In(More)
Heterotrimeric guanine nucleotide-binding regulatory proteins (G proteins) consist of a nucleotide-binding alpha subunit and a high-affinity complex of beta and gamma subunits. There is molecular heterogeneity of beta and gamma, but the significance of this diversity is poorly understood. Different G protein beta and gamma subunits have been expressed both(More)
Vascular endothelial growth factor (VEGF) is a major mediator of pathological angiogenesis, a process necessary for the formation of new blood vessels to support tumor growth. Historically, VEGF is thought to signal via receptor tyrosine kinases, which are not typically considered to be G protein dependent. Here, we show that targeted knockdown of the G(More)