Investigation of novel polypeptide chain releasing factors in Drosophila cells

2015 Fiscal Year Final Research Report

• Project/Area Number: 26840001
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Molecular biology
• Research Institution: The University of Tokyo
• Principal Investigator: KASHIMA Isao 東京大学, 教養学部, 特任准教授 (60613180)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Keywords: translation / termination

Outline of Final Research Achievements

Nonstop mRNA decay (NSD) is quality-control mechanism that detects and degrades mRNAs lacking stop codons. Nonstop protein degradation (NSPD) eliminates aberrant proteins derived from nonstop mRNA. The previous studies in yeast indicate that the Dom34:Hbs1 complex, which are paralogues of mammalian eRF1:eRF3 complex, promotes peptidyle-tRNA release and stalled ribosome dissociation by binding to the empty A site of the stalled ribosome. This enables access of the Ski:Exosome exonuclease complex at 3' end of nonstop mRNAs for subsequent NSD. The E3 ubiquitin ligase Ltn1 is responsible for proteasome-dependent aberrant nonstop polypeptides degradation (NSPD) following the dissociation of ribosome. This study showed that Pelota (Dom34 paralog) and Hbs1 are involved in the degradation of nonstop mRNAs and Ltn1 is essential for NSPD via proteasome pathway in Drosophila Melanogaster cells.

Free Research Field

RNA Biology