Embryonic Poly A Binding Protein (EPABP)

ePABP was identified as a protein that binds AU-rich sequences and prevents shortening of poly(A) tails.ePABP is also expressed in X. laevis testis, suggesting a more general role for ePABP in gametogenesis. ePABP is conserved throughout vertebrates and that mouse and X. laevis cells have similar tissue-specific ePABP expression patterns. ePABP is associated with polysomes and can activate the translation of reporter mRNAs in vivo. Despite its relative divergence from PABP1, ePABP has similar functional domains and can bind to several PABP1 partners, suggesting that they may use similar mechanisms to activate translation. PABP1 and ePABP can interact, suggesting that these proteins may be bound simultaneously to the same mRNA. The activity of both PABP1 and ePABP increases during oocyte maturation, when many mRNAs undergo polyadenylation.