Receptor activity modulating proteins

Superimposed on these signaling proteins are the calmodulins that mediate calcium modulation of receptor function, the /3-ar-restins (70), involved in inactivation of phos-phorylated receptors (6 members), a group of 15 proteins termed RGS (regulators of G-protein signaling), RAMPs (15 receptor-activated modulating proteins), and a protein known as Sst2p that is involved in receptor desensitization. 

Philipp S, Yang XM, Cui L, Davis AM, Downey JM, Cohen MV (2006) Postconditioning protects rabbit hearts through a protein kinase C-adenosine A2b receptor cascade. Cardiovasc Res 70(2) 308-314 Platts SH, Duling BR (2004) Adenosine A3 receptor activation modulates the capillary endothelial glycocalyx. Circ Res 94(l) 77-82... 

FIGURE 23.22 The metabolic effects of insulin. As described in Chapter 34, binding of insulin to membrane receptors stimulates the protein kinase activity of the receptor. Subsequent phosphorylation of target proteins modulates the effects indicated. 

Heptahelical domains are protein modules found in all known G-protein coupled receptors, made up of seven transmembrane helices interconnected by three extra and three intracellular loops. For most G-protein coupled receptors activated by small ligands, the binding site is located in a cavity formed by transmembrane domains 3, 5, 6 and 7. 

Reports that AA is released primarily by G-protein-mediated PLA2 activation remain to be confirmed [84, 85]. In addition, modulation of PLA2 by Ca2+ and protein kinase needs to be better defined. It is clear that NMDA receptor activation promotes the release of AA [86], and that a variety of eicosanoids are then generated (Fig 33-2,33-3). The modulatory events that channel AA towards specific eicosanoids are not understood. The endocannabinoid family of lipid messengers will remain an active focus of interest because of the growing evidence of their actions in synaptic function, learning, memory, and other forms of behavior [56,87]. 

Protein expression and functional difference of membrane-bound and soluble receptor activator of NF-kappaB ligand modulation of the expression by osteotropic factors and cytokines. Biochem Biophys Res Commun 275 768-775... 

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