Two physiological substrate-specific casein kinases are present in the bovine mammary gland.
Two species of casein kinase from lactating bovine mammary gland have been identified; a Ca2+- and CM-independent casein kinase and a Ca2+- and CM-dependent casein kinase. The Ca2+- and CM-independent casein kinase phosphorylates previously dephosphorylated alpha s1-, beta- or kappa-casein while the Ca2+- and CM-dependent casein kinase prefers previously dephosphorylated beta- or kappa-casein as substrates. Two activities are indicated by their substrate specificity, sensitivity to Ca2+ and CM, pH maxima, and differential solubilization by anionic detergents. The presence of a regulated casein kinase in the lactating mammary gland suggests that casein phosphorylation may be a regulator of micelle formation or secretion.
Brooks
C L
CL
Department of Veterinary Pathobiology, Ohio State University, Columbus 43210.
D000818:Animals; D002118:Calcium / Q000502:physiology; D002147:Calmodulin / Q000502:physiology; D047388:Casein Kinases; D002417:Cattle; D003902:Detergents; D004789:Enzyme Activation; D005260:Female; D006863:Hydrogen-Ion Concentration; D008321:Mammary Glands, Animal / Q000201:enzymology*; D011494:Protein Kinases / Q000302:isolation & purification / Q000378:metabolism*; D012995:Solubility; D013379:Substrate Specificity
D002147:Calmodulin; D003902:Detergents; D011494:Protein Kinases; D047388:Casein Kinases; D002118:Calcium