Autophosphorylation of type 2 casein kinase TS at both its α‐ and β‐subunits

Abstract

Rat liver casein kinase TS (Ck‐TS) having quarternary structure α₂β₂, autophosphorylates at its 25 kDa, β‐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 β‐subunit; (ii) stimulators possessing several amino groups (like spermine) which increase the autophosphorylation at the β‐subunit; (iii) stimulators possessing several guanido groups, like protamines and related peptides, which prevent the phosphorylation of the β‐subunit, while promoting the autophosphorylation of the 38 kDa α‐subunit. In the presence of such polyarginyl effectors the 130 kDa Ck‐TS is converted into forms with higher sedimentation coefficient.