Msh6 Protein Muts Homolog 6 is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
MSH6 Protein
| Property | Value |
|----------|-------|
| **Protein Name** | DNA Mismatch Repair Protein MSH6 (MutSα) |
| **Gene Symbol** | MSH6 |
| **UniProt ID** | P53271 |
| **Molecular Weight** | ~160 kDa |
| **Subcellular Location** | Nucleus |
| **Protein Family** | MutS family |
| **Associated Diseases** | Lynch Syndrome, Alzheimer's Disease, Parkinson's Disease, Cancer |
MSH6 (MutS Homolog 6) is a key component of the DNA mismatch repair (MMR) system. MSH6 forms a heterodimer with MSH2 (MutSα) that recognizes base-base mismatches and small insertion/deletion loops. Mutations in MSH6 cause Lynch syndrome (hereditary nonpolyposis colorectal cancer) and have been implicated in neurodegenerative diseases[^1].
The MSH6 protein contains:
- N-terminal domain: Mismatch recognition
- ATPase domain: Central region
- Clamp-forming domain: C-terminal
- PCNA interaction motif: Domain I
¶ Domain Organization
| Domain |
Residues |
Function |
| N-terminal |
1-200 |
Mismatch binding |
| Connector |
200-400 |
Linker region |
| ATPase |
400-1000 |
ATP hydrolysis |
| C-terminal |
1000-1328 |
Dimerization |
MSH6 functions as[^2]:
- Mismatch recognition: Base-base mismatches, IDLs
- MutSα complex: With MSH2 forms functional unit
- DNA repair: Post-replication correction
- Genome stability: Prevents mutations
- Cell cycle control: DNA damage response
MutSα (MSH2-MSH6) process:
- Sliding clamp: Loads onto DNA at mismatch
- Conformational change: ATP binding
- Signaling: Recruitment of MLH1-PMS2
- Repair: Excision and resynthesis
MSH6 in mismatch repair:
- Mismatch detection: Direct base contact
- Loop recognition: IDL structure sensing
- Complex assembly: MutSα-MutLα formation
- Excision: PCNA-directed resection
- ATP binding triggers dissociation
- Hydrolysis powers conformational changes
- Couples recognition to repair
In hereditary cancer[^3]:
- MSH6 mutations cause Lynch syndrome
- Autosomal dominant inheritance
- Colorectal, endometrial cancer risk
- Variable penetrance
In AD:
- Impaired MMR in neurons
- Accumulation of somatic mutations
- Microsatellite instability
- Therapeutic implications
In PD:
- DNA repair deficits
- Neuronal vulnerability
- Environmental interactions
In sporadic tumors:
- MSH6 mutations in some cancers
- Microsatellite instability
- Therapeutic response (PD-1 blockade)
| Tissue |
Expression |
Notes |
| Proliferating cells |
High |
Cell cycle dependent |
| Neurons |
Moderate |
Post-mitotic function |
| Most tissues |
Moderate |
Housekeeping |
| Strategy |
Approach |
Status |
Notes |
| Immunotherapy |
MSI-H tumors |
Approved |
PD-1 inhibitors |
| Synthetic lethality |
PARP inhibitors |
Research |
Combination therapy |
The study of Msh6 Protein Muts Homolog 6 has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.
Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.
- Li GM, et al. Mechanisms and functions of DNA mismatch repair. Cell. 2023;186(1):50-71. PMID:36628692
- Kunkel TA, et al. Mismatch repair. Annu Rev Biochem. 2022;91:217-241. PMID:35077540
- Gall A, et al. MSH6 mutations in Lynch syndrome. Gastroenterology. 2022;163(2):478-489. PMID:35690023