4E-BP2 antibody

Background of 4E-BP2 antibody

PHAS-II, also known as eIF4E-binding protein II (eIF4E-BPII), is a member of a family of proteins which regulate initiation. PHAS-I and -II were found to have overlapping but different patterns of expression in tissues. PHAS-II shows the highest expression in liver and kidney where very little PHAS-I is found. The PHAS proteins regulate translation initiation by binding to the inhibitory protein eIF- 4E and blocking translation by preventing access of eIF-4G to the 5' cap of the mRNA. Both PHAS proteins are phosphorylated in response to insulin or growth factors such as EGF, PDGF and IGF-1. Phosphorylation in the appropriate site(s) promotes dissociation of PHAS/eIF-4E complexes which allows eIF-4E to bind eIF-4G(p220), thereby increasing the amount of eIF-4F complex and the rate of translation initiation. Regulation of the two protein differ because PHAS-II, unlike PHAS-I is readily phosphorylated by PKA in vitro. However increasing cAMP in cells promotes dephosphorylation of both PHAS-I and PHAS-II. Pharmacological and genetic evidence indicates that the mTOR/p70S6K pathway is involved in the control of PHAS-I and -II suggesting that these proteins may be mediators of the effects of this pathway on protein synthesis and cell proliferation.