Comparison of substrate recognition by protein kinase C (type III) between rat liver cytosolic and particulate fractions.
1. Phosphorylation of rat liver endogenous substrates by protein kinase C (type III) was compared between cytosolic and particulate (mitochondria, microsomes and plasma membrane) fractions. 2. The rate and the maximum level of protein phosphorylation were several-fold higher in particulate fractions than in cytosolic fraction. 3. Protein phosphorylation in cytosolic fraction was dependent on both Ca2+ and phospholipid, but only Ca2+ was necessary in phosphorylation of particulate fractions. 4. These results suggest that protein kinase C (type III) has much more target proteins in particulate fractions rather than in cytosolic fraction and Ca2+ was important regulator in particulate protein phosphorylation.
Hashimoto
E
E
Department of Biochemistry, Fukui Medical School, Japan.
Yamamura
H
H
D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D066298:In Vitro Techniques; D008099:Liver / Q000378:metabolism*; D008862:Microsomes, Liver / Q000378:metabolism; D008930:Mitochondria, Liver / Q000378:metabolism; D010766:Phosphorylation; D011493:Protein Kinase C / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D013347:Subcellular Fractions / Q000378:metabolism; D013379:Substrate Specificity
D011506:Proteins; D011493:Protein Kinase C