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Cycloheximide Chase Analysis of Protein Degradation in Saccharomyces cerevisiae
09:05

Cycloheximide Chase Analysis of Protein Degradation in Saccharomyces cerevisiae

Published on: April 18, 2016

Mutant membrane protein of the budding yeast spindle pole body is targeted to the endoplasmic reticulum degradation

Susan McBratney1, Mark Winey

  • 1Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder 80309-0347, USA.

Genetics
|October 26, 2002
PubMed

Insights

Mutations in yeast MPS2 or NDC1 genes cause spindle pole body (SPB) duplication defects. CUE1 gene deletion suppresses these defects, suggesting Mps2p is degraded via the ER quality control pathway.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Genetics

Background:

  • Yeast MPS2 and NDC1 gene mutations cause spindle pole body (SPB) duplication defects, leading to improper nuclear envelope insertion and preventing bipolar mitotic spindle formation.
  • MPS2 and NDC1 encode integral membrane proteins localized at the SPB.

Purpose of the Study:

  • Investigate the role of CUE1 in suppressing mutations in MPS2 and NDC1.
  • Determine the mechanism by which CUE1 suppresses these mutations.

Main Methods:

  • Genetic analysis of yeast mutants.
  • Protein level analysis using Western blotting.
  • Investigating the interaction between CUE1, UBC7, and UBC6.

Main Results:

  • CUE1 acts as a dosage suppressor of mps2 and ndc1 mutations.
  • Deletion of CUE1 restores Mps2-1p protein levels.
  • Disruption of UBC7 or UBC6 also suppresses mps2-1 and ndc1-1 mutations.
  • Mps2p protein levels are reduced in mps2-1 mutants.

Conclusions:

  • CUE1, involved in ER degradation, unexpectedly suppresses SPB duplication defects caused by MPS2 and NDC1 mutations.
  • Mps2p is likely targeted for degradation by the ER quality control pathway.
  • The ubiquitin-conjugating enzymes UBC7 and UBC6 are involved in the degradation of Mps2p.

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