This review will focus on the recent advance in the study of effect of transmembrane Ca2+ gradient on the function of membrane proteins. It consits of two parts: 1. Transmembrane Ca2+ gradient and sarcoplasmic reticulum Ca2+-ATPase; 2. Effect of transmembrane Ca2+ gradient on the components and coupling of cAMP signal transduction pathway. The results obtained indicate that a proper transmembrane Ca2+ gradient may play an important role in modulating the conformation and activity of SR Ca2+-ATPase and the function of membrane proteins involved in the cAMP signal transduction by mediating the physical state change of the membrane phospholipids.
Abbreviations Cai, Ca2+ inside vesicles; Ca0, Ca2+ outside vesicles; SR, sarcoplasmic reticulum; PC, phosphatidylcholine; PS, phosphatidylserine; PG, phosphatidylglycerol; PE, phosphatidylethanolamine; DPH, 1,6-diphenyl-1,3,5-hexatriene; n-AS, n-(9-anthroyloxy) fatty acids; TMA-DPH, 1-(4-trimethylammoniumphenyl)-6)-phenyl-1,3,5-hexatriene; FCCP, carbonylcyanide-p-trifluoromethoxyphenylhydrazone; β-AR, β-adrenergic receptors; DHA, dihydroalprenolol; AC, adenylate cyclase; AC·Lca+−, higher Ca2+ inside vesicles; AC·Lca−−, lower Ca2+ on both side of vesicles; AC·Lca++, higher Ca2+ on both side of vesicles; AC·Lca- +, higher Ca2+ outside vesicles; cAMP, cyclic adenosine monophosphate; Gs, stimulatory GTP-binding protein; GTP, guanosine triposphate; GTPγS, guanosine 5′0-(3-thiotriphosphate);