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

• Published in: Biochemistry (Moscow) 2013-02, Vol.78 (2), p.157-165
• Main Authors: Andreev, D. E., Dmitriev, S. E., Terenin, I. M., Shatsky, I. N.
• Format: Article
• Language: English
• Subjects: 5' Untranslated Regions; Accelerated Publication; Apoptotic Protease-Activating Factor 1 - chemistry; Apoptotic Protease-Activating Factor 1 - genetics; Apoptotic Protease-Activating Factor 1 - metabolism; Base Sequence; Biochemistry; Biomedical and Life Sciences; Biomedicine; Bioorganic Chemistry; Cellular biology; Enzymes; Eukaryotic Initiation Factor-4E - genetics; Eukaryotic Initiation Factor-4E - metabolism; HEK293 Cells; Humans; Life Sciences; Microbiology; Molecular Sequence Data; Protein Biosynthesis; Protein Structure, Secondary; Protein synthesis; Ribonucleic acid; RNA; RNA Caps - genetics; RNA Caps - metabolism; RNA, Messenger - chemistry; RNA, Messenger - genetics; RNA, Messenger - metabolism
• ISSN: 0006-2979; 1608-3040
• DOI: 10.1134/S0006297913020041

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.