Anti-eIF4E

Background: The mRNA Cap-binding protein eIF4E is involved in an early rate limiting step in the initiation of protein synthesis. In response to growth factors and other extracellular stimuli, eIF4E is phosphorylated at Ser209. This phosphorylation increases the affinity of eIF4E to capped-mRNAs. The Mitogen-Activated Protein Kinase Interacting Kinases (Mnk’s) and an insulin-stimulated cytosolic Protamine Kinase (cPK) phosphorylate eIF4E at Ser209 in cells. In vitro, cPK also phosphorylates eIF4E at Thr210.  eIF4E occurs in cells in an inactive form as a complex with inhibitory binding proteins (4EBP). It also occurs in an active form as part of the eIF4F complex which also contains eIF4A and eIF4G. In response to insulin and other extracellular stimuli, eIF4E is recruited to the eIF4F complex following its dissociation from 4EBP. Over-expression of eIF4E leads to cell transformation and tumorigenesis.

Figure:  Western blot of a purified preparation of recombinant human kidney eIF4E with rabbit Anti-eIF4E Polyclonal Antiserum.

References: J Biol Chem 270, 14824-14828;  J Biol Chem 270, 14597-14603; Biochime 76, 822-830;  J Biol Chem 271, 11831-11837;  J Biol Chem 270, 21684-21688