Repression of poly(A)-binding protein (PABP) mRNA translation involves the formation of a heterotrimeric ribonucleoprotein complex by the binding of PABP, insulin-like growth factor II mRNA binding protein-1 (IMP1) and theunrgene encoded polypeptide (UNR) to the adenine-rich autoregu-latory sequence (ARS) located at the 5¢ untranslated region of the PABP-mRNA.