when ca2+/calmodulin-dependent protein kinase ii was added without prior autophosphorylation , there was no phosphorylation of the 63-kda phosphodiesterase subunit or of the kinase itself in the presence of a low concentration of calmodulin , and with excess calmodulin the phosphodiesterase subunit was phosphorylated only at p3 and p4 .
C0031715
phosphorylation
C0031727
kinase