p70S6K

This antibody recognizes Ribosomal Protein S6 Kinase with a molecular mass of 70 kDa (p70-S6K of p70-S6K?1). p70-S6K is a member of a family of serine/threonine protein kinases that phosphorylate the 40S ribosomal protein S6, thereby modulating the translation of ribosomal proteins and translation elongation factors. An isoform, p85-S6K, is derived from the same gene and is identical to p70-S6K with 23 extra residues at the N-terminus, which encode a nuclear localizing signal. p70-S6K is activated in response to the phosphatidylinositol 3-kinase (PI3-K) and mitogen-activated protein kinase (MAPK) pathways, and is required for progression through the cell cycle and for cell growth. Activation of p70-S6K is regulated by phosphorylation of seven different residues distributed throughout the protein, with the critical sites being threonines 229, 389, 421 and serine 424. Phosphorylation is progressive, culminating in phosphoregulation of threonine 229 within the activation loop. This antibody also recognizes p85-S6K.