Phosphorylation of the tumor suppressor gene RB protein by M-phase specific histone H1 kinase.
We have noted the presence of the consensus amino acid sequence for phosphorylation by M-phase specific histone H1 kinase in six sites of the tumor suppressor gene retinoblastoma (RB) protein and determined whether or not RB protein is, in fact, phosphorylated by this kinase. Highly purified enzyme was used for this purpose. Human cell extracts immunoprecipitated with anti-RB antiserum as well as RB proteins expressed in Escherichia coli cells were shown to be phosphorylated by this kinase in vitro. Synthetic peptides for the six expected sites were also phosphorylated. These results suggest the possibility that the function of RB protein is regulated by CDC2 kinase. We also noted the presence of putative phosphorylation sites by H1 kinase in a homologous region between the RB gene and L1 family repetitive sequences.
Taya
Y
Y
Biology Division, National Cancer Center Research Institute, Tokyo, Japan.
Yasuda
H
H
Kamijo
M
M
Nakaya
K
K
Nakamura
Y
Y
Ohba
Y
Y
Nishimura
S
S
D000595:Amino Acid Sequence; D001483:Base Sequence; D016384:Consensus Sequence; D004251:DNA Transposable Elements; D004926:Escherichia coli; D006801:Humans; D016200:Maturation-Promoting Factor / Q000378:metabolism*; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000378:metabolism; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational; D011994:Recombinant Proteins / Q000378:metabolism; D012091:Repetitive Sequences, Nucleic Acid; D016160:Retinoblastoma Protein / Q000378:metabolism*; D012689:Sequence Homology, Nucleic Acid
D004251:DNA Transposable Elements; D010446:Peptide Fragments; D011994:Recombinant Proteins; D016160:Retinoblastoma Protein; D016200:Maturation-Promoting Factor