Roles of Dom34:Hbs1 in Nonstop Protein Clearance from Translocators for Normal Organelle Protein Influx

Toshiaki Izawa, Tatsuhisa Tsuboi, Kazushige Kuroha, Toshifumi Inada, Shuh ichi Nishikawa, Toshiya Endo

Research output: Contribution to journalArticlepeer-review

34 Citations (Scopus)

Abstract

Because messenger RNAs without a stop codon (nonstop mRNAs) generate stalled ribosomes, cells have developed a mechanism allowing degradation of nonstop mRNAs and their translation products (nonstop proteins) in the cytosol. Here, we observe the fate of nonstop proteins destined for organelles such as the endoplasmic reticulum (ER) and mitochondria. Nonstop mRNAs for secretory-pathway proteins in yeast generate nonstop proteins that become stuck in the translocator, the Sec61 complex, in the ER membrane. These stuck nonstop secretory proteins avoid proteasomal degradation in the cytosol, but are instead released into the ER lumen through stalled ribosome and translocator channels by Dom34:Hbs1. We also found that nonstop mitochondrial proteins are cleared from the mitochondrial translocator, the TOM40 complex, by Dom34:Hbs1. Clearance of stuck nonstop proteins from organellar translocator channels is crucial for normal protein influx into organelles and for normal cell growth, especially when nonstop mRNA decay does not function efficiently

Original languageEnglish
Pages (from-to)447-453
Number of pages7
JournalCell Reports
Volume2
Issue number3
DOIs
Publication statusPublished - 2012 Sep 27
Externally publishedYes

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)

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