Specific in vitro activation of Ca,Mg-ATPase by vitamin D-dependent rat renal calcium binding protein (calbindin D28K).
The vitamin D-dependent, calcium-binding protein from rat kidney, calbindin D28k (renal CaBP) specifically stimulates Ca,Mg-ATPase activity of human erythrocyte plasma membranes in a dose-dependent, calcium-sensitive manner. This stimulation was about two-fold compared to a three-fold stimulation by calmodulin. The effect was specific since other calcium-binding proteins and low molecular weight proteins did not stimulate Ca,Mg-ATPase activity. Renal CaBP did not stimulate cyclic nucleotide phosphodiesterase at concentrations greater than those which stimulated Ca,Mg-ATPase activity. This is the first report of a specific in vitro effect of renal CaBP on an enzyme system.
D000818:Animals; D017301:Ca(2+) Mg(2+)-ATPase / Q000097:blood*; D002135:Calcium-Binding Proteins / Q000494:pharmacology*; D000252:Calcium-Transporting ATPases / Q000097:blood*; D002147:Calmodulin / Q000494:pharmacology; D004789:Enzyme Activation; D004910:Erythrocyte Membrane / Q000201:enzymology*; D006801:Humans; D007668:Kidney / Q000378:metabolism*; D007700:Kinetics; D051381:Rats; D064030:S100 Calcium Binding Protein G / Q000378:metabolism / Q000494:pharmacology*
D002135:Calcium-Binding Proteins; D002147:Calmodulin; D064030:S100 Calcium Binding Protein G; D017301:Ca(2+) Mg(2+)-ATPase; D000252:Calcium-Transporting ATPases