The autoregulatory translational control element of poly(A)-binding protein mRNA forms a heteromeric ribonucleoprotein complex.

ABSTRACT: Repression of poly(A)-binding protein (PABP) mRNA translation involves the binding of PABP to the adenine-rich autoregulatory sequence (ARS) in the 5'-untranslated region of its own mRNA. In this report, we show that the ARS forms a complex in vitro with PABP, and two additional polypeptides of 63 and 105 kDa. The 63 and 105 kDa polypeptides were identified, as IMP1, an ortholog of chicken zip-code binding polypeptide, and UNR, a PABP binding polypeptide, respectively, by mass spectrometry of the ARS RNA affinity purified samples. Using a modified ribonucleoprotein (RNP) immunoprecipitation procedure we further show that indeed, both IMP1 and UNR bind to the ARS containing reporter RNA in vivo. Although both IMP1 and UNR could bind independently to the ARS RNA in vitro, their RNA-binding a

SUBMITTER: Patel GP 

PROVIDER: S-EPMC1316114 | biostudies-literature | 2005

REPOSITORIES: biostudies-literature