CA2-DEPENDENT INTERACTION OF CALCYCLIN WITH MEMBRANE()

The presence of calcyclin in the microsomal fraction of Ehrlich ascite s tumor cells was detected using polyclonal antibodies. Association of calcyclin with the microsomes depended on the presence of calcium ion s in the buffer used for cell fractionation. The interaction of calcyc lin with Elhrlich ascites tumor cells microsomes was confirmed in the in vitro conditions by cosedimentation assay using exogenous calcyclin . It was shown that phospholipids extracted from natural membranes and purified phosphatydylserine or phosphatydylcholine were not involved in the binding. Instead, several low molecular weight polypeptides in the Triton X-100 resistant membrane fraction were found to interact wi th calcyclin. (C) 1996 Academic Press, Inc.