Printed in U.S.A. Kinetics and Concentration Dependence of Reversible CAMP-induced Modification of the Surface cAMP Receptor in DictyosteZium*

We have previously reported that extracellular cAMP induced a reversible shift, from apparent M, = 40,000 to 43,000, in the electrophoretic mobility of a polypeptide identified by photoaffinity labeling with [32P]8-N3-cAMP as the cAMP receptor of Dictyoste