The presence of a calcium-sensitive p26-containing complex in bovine retina rod cells

AbstractA protein with apparent Mr, 26 kDa (p26 [(1991) Biokhnya 56, 225-228] or recoverin [(1991) Science 251, 915-918]) was suggested to activate GC in a calcium dependent manner in bovine retina rod cells [(1991) Science 251, 915-918; (1991) EMBO J, 10, 793-798]. However, according to our present data homogeneous p26 preparations do not activate the enzyme. At the same time we have revealed a complex of p26 with an unidentified protein, presumably RK, in bovine ROS. Calcium favours formation of the complex whereas EGTA addition (which corresponds to a low free Ca2+ concentration) leads to its dissociation