Genetic depletion of the RNA helicase DDX3 leads to impaired elongation of translating ribosomes triggering co-translational quality control of newly synthesized polypeptides.

ABSTRACT: DDX3 is a multifaceted RNA helicase of the DEAD-box family that plays central roles in all aspects of RNA metabolism including translation initiation. Here, we provide evidence that the Leishmania DDX3 ortholog functions in post-initiation steps of translation. We show that genetic depletion of DDX3 slows down ribosome movement resulting in elongation-stalled ribosomes, impaired translation elongation and decreased de novo protein synthesis. We also demonstrate that the essential ribosome recycling factor Rli1/ABCE1 and termination factors eRF3 and GTPBP1 are less recruited to ribosomes upon DDX3 loss, suggesting that arrested ribosomes may be inefficiently dissociated and recycled. Furthermore, we show that prolonged ribosome stalling triggers co-translational ubiquitination of nascent po

SUBMITTER: Padmanabhan PK 

PROVIDER: S-EPMC8450092 | biostudies-literature | 2021 Sep

REPOSITORIES: biostudies-literature