2019

RNA Biology

Rocznik: 2019 | Tom: 16 | Numer: 11

artykuł naukowy

angielski

EN The 5MODIFIER LETTER PRIME-UTR of the actin-related protein 2/3 complex subunit 2 (ARPC2) mRNA exists in two variants. Using a bicistronic reporter construct, the present study demonstrates that the longer variant of the 5MODIFIER LETTER PRIME-UTR harbours an internal ribosome entry site (IRES) which is lacking in the shorter one. Multiple control assays confirmed that only this variant promotes cap-independent translation. Furthermore, it includes a guanine-rich region that is capable of forming a guanine-quadruplex (G-quadruplex) structure which was found to contribute to the IRES activity. To investigate the cellular function of the IRES element, we determined the expression level of ARPC2 at various cell densities. At high cell density, the relative ARPC2 protein level increases, supporting the presumed function of IRES elements in driving the expression of certain genes under stressful conditions that compromise cap-dependent translation. Based on chemical probing experiments and computer-based predictions, we propose a structural model of the IRES element, which includes the G-quadruplex motif exposed from the central stem-loop element. Taken together, our study describes the functional relevance of two alternative 5MODIFIER LETTER PRIME-UTR splice variants of the ARPC2 mRNA, one of which contains an IRES element with a G-quadruplex as a central motif, promoting translation under stressful cellular conditions

1622 - 1632

10.1080/15476286.2019.1652524

https://www.tandfonline.com/doi/pdf/10.1080/15476286.2019.1652524

CC BY (uznanie autorstwa)

ostateczna wersja opublikowana

08.2019

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100

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