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Heritable activity: a prion that propagates by covalent autoactivation

B Tibor Roberts1, Reed B Wickner

  • 1Laboratory of Biochemistry and Genetics, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0830, USA.

Genes & Development
|August 19, 2003
PubMed

Insights

Yeast protease B can act as a prion, a self-propagating protein conformation, termed [beta]. This infectious [beta] prion is essential for yeast survival during starvation and sporulation.

Area of Science:

  • Biochemistry
  • Molecular Biology
  • Yeast Genetics

Background:

  • Prions are infectious proteins known to propagate via altered conformations.
  • The theoretical possibility exists for enzymes essential for their own activation to function as prions.

Purpose of the Study:

  • To investigate if yeast protease B can function as a prion.
  • To characterize the properties and biological role of this potential prion.

Main Methods:

  • Induction of de novo prion generation through pro-protease overexpression.
  • Assessing prion infectivity, curability, and biological function in yeast.

Main Results:

  • Yeast protease B was identified as a prion, designated [beta].
  • [beta] prions are infectious, can be reversibly cured, and their formation is triggered by pro-protease overexpression.
  • [beta] is advantageous under starvation and essential for yeast sporulation, despite being masked by protease A in normal conditions.

Conclusions:

  • Yeast protease B acts as a prion ([beta]), demonstrating a novel class of prion behavior.
  • This [beta] prion plays a crucial role in yeast adaptation to starvation and reproduction.
  • The study suggests other enzymes requiring self-modification for activation may also form prions.

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