Autophosphorylation of type 2 casein kinase TS at both its alpha- and beta-subunits. Influence of different effectors.

Rat liver casein kinase TS (Ck-TS) having quaternary structure alpha 2 beta 2, autophosphorylates at its 25 kDa, beta-subunits, incorporating up to 1.2 mol P/mol enzyme. According to their effects on the autophosphorylation pattern the effectors of Ck-TS activity can be grouped into 3 classes: (i) inhibitors, like heparin, which also prevent the autophosphorylation of the beta-subunit; (ii) stimulators possessing several amino groups (like spermine) which increase the autophosphorylation at the beta-subunit; (iii) stimulators possessing several guanido groups, like protamines and related peptides, which prevent the phosphorylation of the beta-subunit, while promoting the autophosphorylation of the 38 kDa alpha-subunit. In the presence of such polyarginyl effectors the 130 kDa Ck-TS is converted into forms with higher sedimentation coefficient.