Identification of Internal Ribosome Entry Segment (IRES)-trans-Acting Factors for the Myc Family of IRESs

• DOI: 10.1128/mcb.01298-07
• Publication Date: 2007-10-29T23:00:12Z
• Authors: Laura C. Cobbold; Keith A. Spriggs; Stephen J. Haines; Helen C. Dobbyn; Christopher Hayes; Cornelia H. de Moor; Kathryn S. Lilley; Martin Bushell; Anne E. Willis
• Keywords: Polypyrimidine tract-binding protein; Polypyrimidine tract

AbstractThe proto-oncogenes c-, L-, and N-myc can all be translated by the alternative method of internal ribosome entry whereby is recruited to a complex structural element (an segment [IRES]). Ribosome recruitment dependent upon presence IRES-trans-acting factors (ITAFs) that act as RNA chaperones allow mRNA attain correct conformation for interaction 40S subunit. One major challenges researchers in this area determine whether there are groups ITAFs regulate IRES-mediated translation subsets mRNAs. We have identified four proteins, termed GRSF-1 (G-rich sequence binding factor 1), YB-1 (Y-box protein PSF (polypyrimidine tract protein-associated splicing factor), its partner, p54nrb, bind myc family IRESs. show these proteins positively Myc oncoproteins (c-, N-Myc) vivo vitro. Interestingly, synthesis from unrelated IRESs, BAG-1 Apaf-1, was not affected YB-1, GRSF-1, or levels vivo, suggesting three specific play role cell proliferation; therefore, results important implications regarding control tumorigenesis. SUPPLEMENTAL MATERIALSupplemental material article may found at http://mcb.asm.org/ .ACKNOWLEDGMENTSThis work supported grants BBSRC (L.C.C., K.A.S., H.C.D., S.J.H., M.B.).We thank James G. Patton his advice help with expression purification PSF.