Endogenous substrates of protein kinase C in experimentally induced and regressed rat thyroid goitres.
The presence of endogenous substrates of the protein kinase C (PKc) in rat thyroid glands has been demonstrated in in vitro phosphorylated cytosolic proteins by polyacrylamide gel electrophoresis (PAGE). Rat thyroid PKc specifically catalyzes the phosphorylation of the 35 kDa and 18 kDa proteins. These proteins were not labelled in the presence of Ca2+ alone, but they were phosphorylated when phospholipids alone were added. In hyperplastic glands the total phosphorylation of endogenous proteins is stimulated, due to the increased labelling of the 35 kDa and 18 kDa proteins. No extra phosphorylated bands were revealed by PAGE analysis. After suppression of growth activity the labelling of the two PKc-specific substrates was strongly inhibited.
D000818:Animals; D003600:Cytosol / Q000378:metabolism; D006042:Goiter / Q000378:metabolism*; D008297:Male; D008970:Molecular Weight; D010750:Phosphoproteins / Q000302:isolation & purification; D010766:Phosphorylation; D011493:Protein Kinase C / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013961:Thyroid Gland / Q000187:drug effects / Q000378:metabolism*; D013974:Thyroxine / Q000494:pharmacology
D010750:Phosphoproteins; D011506:Proteins; D011493:Protein Kinase C; D013974:Thyroxine