The major phosphorylation site of nucleophosmin (B23) is phosphorylated by a nuclear kinase II.
Nucleophosmin (B23) was phosphorylated in vitro with [gamma-32P]ATP and a nuclear kinase (type II) purified from HeLa cells. The phosphorylation was inhibited by heparin and by 2,3-diphosphoglycerate. Peptide mapping analysis indicated that the phosphorylation site in vitro was identical to that in vivo. Purified nucleoli have a similar kinase that phosphorylated nucleophosmin at the same site. These results indicated that nucleophosmin is phosphorylated in vivo by a nucleolar kinase (type II).
Department of Pharmacology, Baylor College of Medicine, Houston, TX 77030.
P K
PK
Chan
Q R
QR
Liu
E
E
Durban
D019794:2,3-Diphosphoglycerate; D000595:Amino Acid Sequence; D001665:Binding Sites; D002466:Cell Nucleolus / Q000201:enzymology; D002467:Cell Nucleus / Q000201:enzymology*; D004163:Diphosphoglyceric Acids / Q000494:pharmacology; D006367:HeLa Cells; D006493:Heparin / Q000494:pharmacology; D006801:Humans; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000378:metabolism*; D000090243:Nucleophosmin; D010449:Peptide Mapping; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism*
D004163:Diphosphoglyceric Acids; C000716967:NPM1 protein, human; D009687:Nuclear Proteins; D000090243:Nucleophosmin; D019794:2,3-Diphosphoglycerate; D006493:Heparin; D011494:Protein Kinases; C026813:protein kinase NII