Expression and regulation of casein kinase 2 during heat shock in Verticillium dahliae

A homogeneous preparation of casein kinase 2 has been isolated from the phytopathogenic fungus Verticillium dahliae (the parasite of cotton). The enzyme consists of three subunits with molecular masses of 53, 41, and 38 kDa. Highly specific immune serum against casein kinase 2 has been obtained. By means of immunoblotting, enzyme‐linked immunosorbent assay (ELISA), and immunochemical isolation on protein A‐Sepharose, it is shown that the amount of casein kinase 2 increases under heat shock conditions (at least in part due to the synthesis de novo), while the synthesis of the majority of other proteins falls. The activity of casein kinase 2 is supressed during heat shock and so does not correlate with its content. The results give an evidence for the two‐step model of casein kinase 2 regulation during heat shock.