Functional characterization of 5′ UTR cis-acting sequence elements that modulate translational efficiency in Plasmodium falciparum and humans

Malaria Journal

Valentina E. Garcia¹  Joseph L. DeRisi²  Rebekah Dial³ 

[1] Department of Biochemistry and Biophysics, Univeristy of California, San Francisco, 600 16th St, 94158, San Francisco, CA, USA;Department of Biochemistry and Biophysics, Univeristy of California, San Francisco, 600 16th St, 94158, San Francisco, CA, USA;Chan Zuckerberg Biohub, 499 Illinois St, 94158, San Francisco, CA, USA;Department of Biochemistry and Biophysics, Univeristy of California, San Francisco, 600 16th St, 94158, San Francisco, CA, USA;Denali Therapeutics, Biotherapeutic Discovery, 161 Oyster Point Blvd, 94080, South San Francisco, CA, USA;

关键词: In vitro translation;    Translation initiation;    Upstream “AUG”s;    Upstream open reading frames;   

DOI  :  10.1186/s12936-021-04024-2

来源: Springer

【 摘 要 】

BackgroundThe eukaryotic parasite Plasmodium falciparum causes millions of malarial infections annually while drug resistance to common anti-malarials is further confounding eradication efforts. Translation is an attractive therapeutic target that will benefit from a deeper mechanistic understanding. As the rate limiting step of translation, initiation is a primary driver of translational efficiency. It is a complex process regulated by both cis and trans acting factors, providing numerous potential targets. Relative to model organisms and humans, P. falciparum mRNAs feature unusual 5′ untranslated regions suggesting cis-acting sequence complexity in this parasite may act to tune levels of protein synthesis through their effects on translational efficiency.MethodsHere, in vitro translation is deployed to compare the role of cis-acting regulatory sequences in P. falciparum and humans. Using parasite mRNAs with high or low translational efficiency, the presence, position, and termination status of upstream “AUG”s, in addition to the base composition of the 5′ untranslated regions, were characterized.ResultsThe density of upstream “AUG”s differed significantly among the most and least efficiently translated genes in P. falciparum, as did the average “GC” content of the 5′ untranslated regions. Using exemplars from highly translated and poorly translated mRNAs, multiple putative upstream elements were interrogated for impact on translational efficiency. Upstream “AUG”s were found to repress translation to varying degrees, depending on their position and context, while combinations of upstream “AUG”s had non-additive effects. The base composition of the 5′ untranslated regions also impacted translation, but to a lesser degree. Surprisingly, the effects of cis-acting sequences were remarkably conserved between P. falciparum and humans.ConclusionsWhile translational regulation is inherently complex, this work contributes toward a more comprehensive understanding of parasite and human translational regulation by examining the impact of discrete cis-acting features, acting alone or in context.

【 授权许可】

CC BY