Host factors required for internal initiation of translation on poliovirus RNA

1996 Fiscal Year Final Research Report Summary

• Project/Area Number: 07457081
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Virology
• Research Institution: The University of Tokyo
• Principal Investigator: TOYODA Haruka The University of Tokyo, The Institute of Medical Science, Lecturer, 医科学研究所, 講師 (10197973)
• Project Period (FY): 1995 – 1996
• Keywords: Poliovirus / IRES / Host factor / in vitro translation / UV-corosslinking

Research Abstract

Translation of poliovirus (PV) RNA is initiated by entry of ribosomes into the nucleotide sequence (internal ribosomal entry site ; IRES) with in the 5'-untranslated region (5'-UTR) and contains 5 stem loop (SL) structures. Efficiency of this translation initiation in rabbit reticulocyte lysates (RRL) was very poor and was greatly enhanced by the addition of the ribosomal salt-wash fraction (RSW) prepared from HeLa cells. This stimulation activity in the RSW was partially purified and its molecular weight was estimated to be more than 240,000. Several proteins that bind spoecifically to these SL structures in this poliovirus IRES were detected. Among those, a 57 kDa protein, recognized by antibodies against polypyrimidide tract-binding protein (PTB), and a 40 kDa protein (p40) which is identified as PCBP2 (polyC binding protein) bound to SLIV.In addition, 36 kDa (p36) and 80kDa (p80) proteins bind to SLV spesifically. The purification of p36 and p80 are now on progress.