Construction of Tight Conditional Mutants Using the Improved Auxin-Inducible Degron (iAID) Method in the Budding Yeast Saccharomyces cerevisiae

Methods Mol Biol. 2021:2196:15-26. doi: 10.1007/978-1-0716-0868-5_2.


Conditional mutants, such as temperature-sensitive (ts) mutants, are effective tools for the analysis of essential genes. However, such mutants are frequently leaky. To overcome this problem, it is helpful to isolate a "tight" conditional mutant of a gene of interest, e.g., by using ubiquitin-mediated protein degradation to eliminate the gene product. One such strategy is the auxin-inducible degron (AID) system, which is easy to use because the simple addition of auxin can induce the degradation of a target protein. Sometimes, however, elimination of the target protein is not sufficient, and an AID mutant exhibits a "leaky" phenotype. To address this issue, the improved AID (iAID) system was developed. In this approach, transcriptional repression by the "Tet-OFF" promoter is combined with proteolytic elimination of the target protein by the AID system, yielding a much tighter mutant. Because simple addition of tetracycline is sufficient to repress the Tet-OFF promoter, the combination of Tet-OFF and AID maintains the ease of use of the original AID system. In this manuscript, we describe how to construct and use iAID mutants in the budding yeast Saccharomyces cerevisiae.

Keywords: Auxin-inducible degron (AID); Budding yeast; Conditional mutant; Tet-OFF promoter.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Fungal Proteins / genetics*
  • Gene Expression Regulation, Fungal / drug effects*
  • Gene Order
  • Genetic Vectors / genetics
  • Indoleacetic Acids / pharmacology*
  • Mutation*
  • Plasmids / genetics
  • Polymerase Chain Reaction
  • Promoter Regions, Genetic
  • Saccharomycetales / drug effects*
  • Saccharomycetales / genetics*
  • Transformation, Genetic


  • Fungal Proteins
  • Indoleacetic Acids