Phosphorylation of proteasome substrate by a protein kinase associated with the 26 S proteasome is linked to the ATP-dependent proteolysis of the 26 S proteasome.
A protein kinase phosphorylating the 45-kDa proteasome subunit was co-purified with the 26 S proteasome from the porcine heart. This kinase appears to be associated with the 26 S proteasome, since the kinase activity was co-eluted with the 26 S proteasome on Superose 6 FPLC and immunoprecipitated with anti-20 S proteasome antibody. This kinase also phosphorylated the casein. Furthermore, the phosphorylated casein was more efficiently hydrolyzed by the 26 S proteasome than the dephosphorylated casein without ATP. Inhibition patterns of kinase inhibitors against the 45 kDa subunit and casein were well in accord with the inhibition pattern against the ATP-dependent proteolysis of the 26 S proteasome, suggesting that the phosphorylation of casein by a protein kinase associated with the 26 S proteasome is linked to the ATP-dependent proteolysis of the 26 S proteasome.
Satoh
K
K
Department of Biochemistry, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan.
Nishikawa
T
T
Yokosawa
H
H
Sawada
H
H
D000255:Adenosine Triphosphate / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D002850:Chromatography, Gel; D003546:Cysteine Endopeptidases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D009206:Myocardium / Q000201:enzymology*; D010210:Papillary Muscles / Q000201:enzymology; D010446:Peptide Fragments / Q000737:chemistry / Q000302:isolation & purification; D010766:Phosphorylation; D046988:Proteasome Endopeptidase Complex; D011494:Protein Kinases / Q000302:isolation & purification / Q000378:metabolism*; D013379:Substrate Specificity; D013552:Swine
D046911:Macromolecular Substances; D009097:Multienzyme Complexes; D010446:Peptide Fragments; D000255:Adenosine Triphosphate; D011494:Protein Kinases; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex