A cellular protein that binds to the 5'-noncoding region of poliovirus RNA: implications for internal translation initiation.

Abstract

Initiation of translation on poliovirus mRNA occurs by internal binding of ribosomes to a region within the 5'-noncoding portion of the mRNA. The mechanistic details and trans-acting factors involved in this event are not understood fully. We used a mobility-shift electrophoresis assay to identify a specific RNA-protein complex, which can form between an RNA fragment that contains nucleotides 559--624 of the poliovirus 5' UTR {untranslated region) and a component or components of a HeLa cell extract. Complex formation was reduced greatly in a reticulocyte lysate or a wheat-germ extract. A 52-kD polypeptide (p52) has been identified as part of the protein-RNA complex by use of an UV cross-linking assay. This polypeptide apparently is not a known translation initiation or elongation factor. The possible involvement of p52 in translation initiation of poliovirus protein synthesis is discussed.

Akt phosphorylation of La regulates specific mRNA translation in glial progenitors

“…The polyribosome association of La in cell lines has suggested La's involvement in translational regulation (Meerovitch et al, 1989(Meerovitch et al, , 1993. Our data furthermore present evidence that phosphorylation of La T301 is essential for polyribosome association in glial progenitor cells.…”

A cellular 57 kDa protein binds to two regions of the internal translation initiation site of foot‐and‐mouth disease virus

“…Binding of cellular proteins to multiple sites [7], and interaction of a 52 kDa protein with a specific region of this internal entry site of poliovirus RNA [8] have been reported. Very recently, binding of a 58 kDa protein from mouse ascites cells to the 5 ' -UTR of encephalomyocarditis virus (EMCV) has been observed upon UV-crosslinking [9].…”

La Autoantigen Mediates Oxidant Induced De Novo Nrf2 Protein Translation

“…These features are important for its functions from tRNA maturation to stabilization and nuclear export of nascent mRNA (30,31). La/SSB was the first ITAF identified for promoting translation of poliovirus (32), and later found to mediate translation of HBV, HCV, HIV, encephalomyocarditis, and giardia viruses (30). For cellular proteins, La/SSB functions as an ITAF for translation of cyclin D1 (33), XIAP (6), BiP (34), and MDM2 (35).…”