English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

In vertebrates, the mRNAs encoding ribosomal proteins, as well as other proteins implicated in translation, are characterized by a 5'-untranslated region (5'-UTR), including a stretch of pyrimidines at the 5'-end. The 5'-terminal oligopyrimidine (5'-TOP) sequence, which is involved in the growth-dependent translational regulation characteristic of this class of genes (so-called TOP genes), has been shown to specifically bind the La protein in vitro, suggesting that La might be implicated in translational regulation in vivo. In order to substantiate this hypothesis, we have examined the effect of La on TOP mRNA translational control in both stable and transient transfection experiments. In particular we have constructed and analyzed three stably transfected Xenopus cell lines inducible for overexpression of wild-type La or of putative dominant negative mutated forms. Moreover, La-expressing plasmids have been transiently co-transfected together with a plasmid expressing a reporter TOP mRNA in a human cell line. Our results suggest that in vivo La protein plays a positive role in the translation of TOP mRNA. They also suggest that the function of La is to counteract translational repression exerted by a negative factor, possibly cellular nucleic acid binding protein (CNBP), which has been previously shown to bind the 5'-UTR downstream from the 5'-TOP sequence.

La protein has a positive effect on the translation of TOP mRNAs in vivo