Factors that control translational fidelity in mammalian cells
Description: Translational readthrough (TR) occurs when ribosomes continue to synthesize a protein beyond a stop codon and extend this protein in the C-terminal, providing a new localization signal or the possibility to interact with a new partner. During the previous tenure of this grant, we found that TR can be assessed in mammalian cells with appropriate dual luciferase reporters. We found that TR is decreased in senescent cells and that this decrease depends on the activity of the retinoblastoma (RB) tumor suppressor. Our project consists in identifying the mechanism by which RB reduces TR and to characterize TR events that depend upon RB. When the RB pathway is inactivated in senescent cells using either the oncoprotein E7 or the kinase CDK4, TR activity is restored. RB represses the transcription of tRNAs genes by interfering with RNA polymerase III. First, we will overexpress natural tRNAs known to be near cognate to non-sense codons UAA or UAG (tRNATyr, tRNAGln, tRNALys) and we expect that this overexpression will restore TR efficiency in senescent cells. Second, to characterize TR events stimulated by RB pathway inactivation, we will use ribosome profiling and bioinformatics. Our long- term goal is to provide a resource that maps TR events in mammalian cells and to characterize the functional pathways that can be potentially affected by this mechanism.
Amount: CA$29,600
Funding type: research
Funder scheme: Discovery Grants Program - Individual
Start date: 2020-04-01
End date: 2021-03-31
Investigator: Léa Brakier-Gingras
Institution: Université de Montréal
Topic: RNA modifications and cancer
Subfield: Molecular Biology
Domain: Life Sciences
Funded outputs count: 0
Funder award ID: rgpin-2019-04980
OpenAlex ID: G1953569145