Curing of the [URE3] prion by Btn2p, a Batten disease-related protein

EMBO J. 2008 Oct 22;27(20):2725-35. doi: 10.1038/emboj.2008.198. Epub 2008 Oct 2.

Abstract

[URE3] is a prion (infectious protein), a self-propagating amyloid form of Ure2p, a regulator of yeast nitrogen catabolism. We find that overproduction of Btn2p, or its homologue Ypr158 (Cur1p), cures [URE3]. Btn2p is reported to be associated with late endosomes and to affect sorting of several proteins. We find that double deletion of BTN2 and CUR1 stabilizes [URE3] against curing by several agents, produces a remarkable increase in the proportion of strong [URE3] variants arising de novo and an increase in the number of [URE3] prion seeds. Thus, normal levels of Btn2p and Cur1p affect prion generation and propagation. Btn2p-green fluorescent protein (GFP) fusion proteins appear as a single dot located close to the nucleus and the vacuole. During the curing process, those cells having both Ure2p-GFP aggregates and Btn2p-RFP dots display striking colocalization. Btn2p curing requires cell division, and our results suggest that Btn2p is part of a system, reminiscent of the mammalian aggresome, that collects aggregates preventing their efficient distribution to progeny cells.

Publication types

  • Research Support, N.I.H., Intramural

MeSH terms

  • Amino Acid Transport Systems / genetics*
  • Amino Acid Transport Systems / metabolism
  • Amino Acid Transport Systems / physiology*
  • Fungal Proteins / metabolism
  • Gene Deletion
  • Gene Expression Regulation, Fungal*
  • Glutathione Peroxidase
  • Green Fluorescent Proteins / metabolism
  • Models, Biological
  • Models, Genetic
  • Molecular Chaperones / genetics
  • Molecular Chaperones / physiology
  • Plasmids / metabolism
  • Prions / chemistry*
  • Promoter Regions, Genetic
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins / chemistry*
  • Saccharomyces cerevisiae Proteins / genetics*
  • Saccharomyces cerevisiae Proteins / metabolism
  • Saccharomyces cerevisiae Proteins / physiology*

Substances

  • Amino Acid Transport Systems
  • BTN2 protein, S cerevisiae
  • CUR1 protein, S cerevisiae
  • Fungal Proteins
  • Molecular Chaperones
  • Prions
  • Saccharomyces cerevisiae Proteins
  • Green Fluorescent Proteins
  • Glutathione Peroxidase
  • URE2 protein, S cerevisiae