MutSα mismatch repair protein stability is governed by subunit interaction, acetylation, and ubiquitination

Autor: Tim Arlow, Junwon Kim, Emma Zorensky, Mark D. Rose, Cristina Balbás Martínez, Joanna E Haye-Bertolozzi, Caitlin Fay, Alison E. Gammie
Rok vydání: 2020
Předmět:
AcademicSubjects/SCI01140
congenital
hereditary
and neonatal diseases and abnormalities

Saccharomyces cerevisiae Proteins
DNA Repair
AcademicSubjects/SCI00010
Saccharomyces cerevisiae
MutS
QH426-470
AcademicSubjects/SCI01180
DNA Mismatch Repair
03 medical and health sciences
0302 clinical medicine
Genetics
Molecular Biology
neoplasms
Genetics (clinical)
030304 developmental biology
chemistry.chemical_classification
Investigation
0303 health sciences
DNA ligase
biology
Protein Stability
Mutagenesis
dimer stabilization
Ubiquitination
nutritional and metabolic diseases
Acetylation
Mismatch Repair Protein
biology.organism_classification
digestive system diseases
Cell biology
mismatch repair
MutS Homolog 2 Protein
MSH3
chemistry
MSH2
030220 oncology & carcinogenesis
AcademicSubjects/SCI00960
DNA mismatch repair
Zdroj: G3: Genes|Genomes|Genetics
G3: Genes, Genomes, Genetics, Vol 11, Iss 3 (2021)
ISSN: 2160-1836
Popis: In eukaryotes, DNA mismatch recognition is accomplished by the highly conserved MutSα (Msh2/Msh6) and MutSβ (Msh2/Msh3) complexes. Previously, in the yeast Saccharomyces cerevisiae, we determined that deleting MSH6 caused wild-type Msh2 levels to drop by ∼50%. In this work, we determined that Msh6 steady-state levels are coupled to increasing or decreasing levels of Msh2. Although Msh6 and Msh2 are reciprocally regulated, Msh3 and Msh2 are not. Msh2 missense variants that are able to interact with Msh6 were destabilized when Msh6 was deleted; in contrast, variants that fail to dimerize were not further destabilized in cells lacking Msh6. In the absence of Msh6, Msh2 is turned over at a faster rate and degradation is mediated by the ubiquitin-proteasome pathway. Mutagenesis of certain conserved lysines near the dimer interface restored the levels of Msh2 in the absence of Msh6, further supporting a dimer stabilization mechanism. We identified two alternative forms of regulation both with the potential to act via lysine residues, including acetylation by Gcn5 and ubiquitination by the Not4 ligase. In the absence of Gcn5, Msh2 levels were significantly decreased; in contrast, deleting Not4 stabilized Msh2 and Msh2 missense variants with partial function. The stabilizing effect on Msh2 by either the presence of Msh6 or the absence of Not4 are dependent on Gcn5. Taken together, the results suggest that the wild-type MutSα mismatch repair protein stability is governed by subunit interaction, acetylation, and ubiquitination.
Databáze: OpenAIRE