Title Information
Title
Ubiquitin-Dependent Proteolysis of the Yeast Mating-Type Regulator Matalpha1
Name: Personal
Name Part
Nixon, Christina Erin
Role
Role Term: Text
creator
Origin Information
Copyright Date (keyDate="yes", encoding="w3cdtf")
2009
Physical Description
Extent
xiv, 203 p.
digitalOrigin
born digital
Note
Thesis (Ph.D.) -- Brown University (2010)
Name: Personal
Name Part
Laney, Jeffrey
Role
Role Term: Text
director
Name: Personal
Name Part
Landy, Arthur
Role
Role Term: Text
reader
Name: Personal
Name Part
Mowry, Kimberly
Role
Role Term: Text
reader
Name: Personal
Name Part
Freiman, Richard
Role
Role Term: Text
reader
Name: Personal
Name Part
Johnson, Erica
Role
Role Term: Text
reader
Name: Corporate
Name Part
Brown University. Division of Biology and Medicine. Molecular Biology, Cell Biology, and Biochemistry
Role
Role Term: Text
sponsor
Genre (aat)
theses
Abstract
Cell type in budding yeast is controlled by the master regulatory transcription factors encoded at the mating-type (MAT) locus Mat?1, Mat?2, and Mata1. In homothallic strains, the a and ? haploid cell types are unstable states, and cell type switching can occur with high frequency. To facilitate such efficient switching, the Mat transcription factors are unstable proteins. At least one of these factors, Mat?2, is degraded by the ubiquitin-proteasome system (UPS). It stands to reason that the UPS would also degrade the other ?-specific regulator, Mat?1. Understanding how Mat?1 is degraded and if it is degraded coordinately with Mat?2 will provide a model to study other phenotypic switching events. Here, I demonstrate that Mat?1 is a substrate for the UPS and is targeted for proteolysis by multiple E2 and E3 enzymes, including one common pathway with Mat?2: Ubc4/Ubc5/Slx5-Slx8. Interestingly, Mat?1 turnover requires an intact sumoylation pathway as well as poly-SUMO chains, whereas Mat?2 does not. Using a series of Mat?1 deletion mutants fused to Ura3 (the normally stable uracil biosynthetic enzyme), I have also isolated several regions within Mat?1 that are necessary for rapid turnover potentially corresponding to the multiple ubiquitin ligases. Interestingly, a region coinciding with the alpha1 domain (residues 75-150), while not sufficient to confer wild-type levels of instability to Ura3, is dependent upon Slx5-Slx8. Taken together, these data show that while the degradation pathways of Mat?1 and Mat?2 share commonalities, the details of the pathways are unique for each factor.
Subject (Local)
Topic
MATalpha1
Subject (Local)
Topic
ubiquitin-proteasome system
Subject (Local)
Topic
protein degradation
Subject (Local)
Topic
mating-type switching
Subject (Local)
Topic
SUMO
Subject (Local)
Topic
Slx5
Subject (Local)
Topic
Slx8
Subject (Local)
Topic
Ufd4
Subject (Local)
Topic
Ubc13
Subject (Local)
Topic
Ubc4
Subject (Local)
Topic
Ubc5
Subject (FAST) (authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/1182596")
Topic
Yeast
Subject (FAST) (authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/1930489")
Topic
Proteolysis
Record Information
Record Content Source (marcorg)
RPB
Record Creation Date (encoding="iso8601")
20091218
Language
Language Term: Code (ISO639-2B)
eng
Language Term: Text
English
Identifier: DOI
10.7301/Z0M043PC
Access Condition: rights statement (href="http://rightsstatements.org/vocab/InC/1.0/")
In Copyright
Access Condition: restriction on access
Collection is open for research.
Type of Resource (primo)
dissertations