Crucial role of ATP-bound Sse1 in Upf1-dependent degradation of the truncated product

Biochem Biophys Res Commun. 2017 Jun 17;488(1):122-128. doi: 10.1016/j.bbrc.2017.05.020. Epub 2017 May 5.

Abstract

Up-frameshift (Upf) complex facilitates the degradation of aberrant mRNAs containing a premature termination codon (PTC) and its products in yeast. Here we report that Sse1, a member of the Hsp110 family, and Hsp70 play a crucial role in Upf-dependent degradation of the truncated FLAG-Pgk1-300 protein derived from PGK1 mRNA harboring a PTC at codon position 300. Sse1 was required for Upf-dependent rapid degradation of the FLAG-Pgk1-300. FLAG-Pgk1-300 was significantly destabilized in ATP hydrolysis defective sse1-1 mutant cells than in wild type cells. Consistently, Sse1 and Hsp70 reduced the level of an insoluble form of FLAG-Pgk1-300. We propose that the Sse1/Hsp70 complex maintains the solubility of FLAG-Pgk1-300, thereby stimulating its Upf-dependent degradation by the proteasomes.

Keywords: Hsp70/Sse1 complex; Nonsense-mediated decay; Proteasome; Ubiquitination.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphate / metabolism*
  • HSP70 Heat-Shock Proteins / metabolism*
  • RNA Helicases / metabolism*
  • Saccharomyces cerevisiae Proteins / metabolism*

Substances

  • HSP70 Heat-Shock Proteins
  • SSE1 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins
  • Adenosine Triphosphate
  • NAM7 protein, S cerevisiae
  • RNA Helicases