IndraLab
Statements
"Phosphorylated by cdk6 and cdk4, and subsequently by cdk2 at ser-567 in g1, thereby releasing e2f1 which is then able to activate cell growth. Here we show that although these cdks phosphorylate multiple residues in prb, they do so with different residue selectivities in vitro;thr821 and thr826 are preferentially phosphorylated by cdk6 and cdk4, respectively."
"The retinoblastoma gene product (prb) is a nuclear phosphoprotein that is thought to play a key role in the negative regulation of cellular proliferation. The active form of prb is underphosphorylated. Using synthetic peptides corresponding to potential cdc2 phosphorylation sites, we have developed a strategy which has allowed the identification of five sites. S249, t252, t373, s807 and s811 are phosphorylated in vivo, and in each case these sites correspond closely to the consensus sequence for phosphorylation by p34cdc2."