Chimeric G alpha s/G alpha i2 proteins define domains on G alpha s that interact with tubulin for beta-adrenergic activation of adenylyl cyclase.

G alpha 12 and G alpha 13 subunits define a fourth class of G protein alpha subunits.

Heterotrimeric guanine nucleotide-binding regulatory proteins (G proteins) are central to the signaling processes of multicellular organisms. We have explored the diversity of the G protein subunits in mammals and found evidence for a large family of genes that encode the alpha subunits. Amino acid sequence comparisons show that the different alpha subunits fall into at least three classes. The...

Cardiac adenylyl cyclase, beta-adrenergic receptors, and G proteins in salt-sensitive hypertension.

The present study investigated whether high salt intake (8%) in Dahl salt-sensitive and salt-resistant rats with and without hypertension produces a heterologous desensitization of cardiac adenylyl cyclase as observed in various types of hypertension and human heart failure. In membranes from Dahl salt-sensitive rats on a high-salt diet (8%) basal, isoproterenol-, 5'-guanylylimidodiphosphate-, ...

G-protein alpha and beta–gamma subunits interact with conformationally distinct signaling states of rhodopsin

Light activated rhodopsin interacts with domains on all three subunits of transducin. Two of these domains, the C-terminal regions of the alpha and gamma subunits mimic the ability of transducin to stabilize the active conformation of rhodopsin, metarhodopsin II, but display different roles in transducin activation process. Whether the interactions are with the same or different complimentary s...

The turkey erythrocyte beta-adrenergic receptor couples to both adenylate cyclase and phospholipase C via distinct G-protein alpha subunits.

By contrast with mammalian beta-adrenergic receptors, the avian isoform elicits two distinct effector responses, activation of adenylate cyclase and polyphosphoinositide-specific phospholipase C (PLC) leading to the accumulation of both cyclic adenosine monophosphate (cyclic AMP) and inositol phosphates. We have investigated the mechanisms of beta-adrenergic receptor signalling in turkey erythr...

Any alpha(G) upper bound below chi(G) whenever alpha(G) < chi(G) is NP-hard to compute