title: Cap-independent translation initiation of apaf-1 mRNA based on a scanning mechanism is determined by some features of the secondary structure of its 5' untranslated region.
abstract: We have earlier shown that the 5'-untranslated region (5' UTR) of the mRNA coding for activation factor of apoptotic peptidase 1 (Apaf-1) can direct translation in vivo by strictly 5' end-dependent way even in the absence of m(7)G-cap. Dependence of translational efficiency on the cap availability for this mRNA turned out to be relatively low. In this study we demonstrate that this surprising phenomenon is determined the 5'-proximal part (domains I and II) of highly structured Apaf-1 5' UTR. Remarkably, domain II by itself was able to reduce dependence of the mRNA on the cap on its transferring to a short 5' UTR derived from a standard vector. We suggest that the low cap-dependence inherent to some cellular mRNAs may have an important physiological significance under those stress conditions when the function of cap-binding factor eIF4E is impaired.
authors.affiliation: Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119994 Moscow, Russia.
authors.forename: D E
authors.initials: DE
authors.lastname: Andreev
authors.forename: S E
authors.initials: SE
authors.lastname: Dmitriev
authors.forename: I M
authors.initials: IM
authors.lastname: Terenin
authors.forename: I N
authors.initials: IN
authors.lastname: Shatsky
mesh_terms: D020121:5' Untranslated Regions; D053477:Apoptotic Protease-Activating Factor 1 / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D039561:Eukaryotic Initiation Factor-4E / Q000235:genetics / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D008969:Molecular Sequence Data; D014176:Protein Biosynthesis; D017433:Protein Structure, Secondary; D012315:RNA Caps / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D020121:5' Untranslated Regions; D053477:Apoptotic Protease-Activating Factor 1; D039561:Eukaryotic Initiation Factor-4E; D012315:RNA Caps; D012333:RNA, Messenger