Phosphorylation pattern of liver proteins during the early stages of the acute-phase response.

Liver preparations from turpentine-treated rats show an increased capacity to autophosphorylate a protein of 32.5 kDa (p 32.5): both the kinase and the substrate protein are strongly bound to the membrane fraction, but the protein is released to the cytosol after phosphorylation, which occurs exclusively in serine residues. No known second messenger-dependent protein kinase seems to be responsible for the reaction. Phosphorylation of p 32.5 could be an early post-receptorial event after turpentine-treatment possibly caused by cytokines and involved in the pathogenesis of further events of the acute-phase response.