XXXX @entity72856 and @entity72857 loss of function inhibits cell growth and causes animal death in a @entity72858 -independent manner.

@entity72856 @entity72858 @entity1547 @entity72857 @entity238
@entity1547 ( @entity1547 ) is a surveillance mechanism that degrades transcripts containing nonsense mutations, preventing the translation of truncated proteins. @entity1547 also regulates the levels of many endogenous mRNAs. While the mechanism of @entity1547 is gradually understood, its physiological role remains largely unknown. The core @entity1547 genes @entity72856 and @entity72857 are essential in several organisms, which may reflect an important developmental role for @entity1547 . Alternatively, the lethality of these mutants might arise from their function in @entity1547 -independent processes. To analyze the developmental importance of @entity1547 , we studied @entity238 mutants of the other core @entity1547 gene, @entity72858 . We compare the resulting @entity72858 phenotype with those defects observed in @entity72856 and @entity72857 loss-of-function mutants, as well as with flies expressing a mutant @entity72857 protein unable to bind @entity72858 . Our results show that @entity72858 is an @entity1547 effector in the @entity238 but, unlike @entity72856 and @entity72857 , plays a peripheral role in the degradation of most @entity1547 targets and is not required for development or viability. Furthermore, @entity72856 and @entity72857 loss-of-function inhibits cell growth and induces apoptosis through a @entity72858 -independent pathway. Accordingly, disruption of @entity72857 - @entity72856 interaction causes death, while the @entity72857 - @entity72858 complex is dispensable for viability. Our findings suggest that @entity1547 is essential for cell growth and animal development, and that the lethality of @entity72856 and @entity72857 mutants is not due to disrupting their roles during @entity1547 -independent processes, but to their function in the degradation of specific mRNAs by the @entity1547 pathway. Furthermore, our results show that @entity72858 is not always essential in @entity1547 .
