MSH6 Protein - MutS Homolog 6

MSH6 Protein

Introduction

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.

<div class="infobox infobox-protein">
<span class="infobox-title">MSH6 Protein</span>
| 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 |
</div>

Overview

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[@li2023].

Structure

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 |

Normal Function

...

MSH6 Protein

Introduction

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.

<div class="infobox infobox-protein">
<span class="infobox-title">MSH6 Protein</span>
| 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 |
</div>

Overview

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[@li2023].

Structure

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 |

Normal Function

MSH6 functions as[@kunkel2022]:

• 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

Mismatch Recognition

MutSα (MSH2-MSH6) process:

Sliding clamp: Loads onto DNA at mismatch

Conformational change: ATP binding

Signaling: Recruitment of MLH1-PMS2

Repair: Excision and resynthesis

Molecular Mechanisms

DNA Repair

MSH6 in mismatch repair:

Mismatch detection: Direct base contact

Loop recognition: IDL structure sensing

Complex assembly: MutSα-MutLα formation

Excision: PCNA-directed resection

ATP Hydrolysis

• ATP binding triggers dissociation
• Hydrolysis powers conformational changes
• Couples recognition to repair

Disease Associations

Lynch Syndrome

In hereditary cancer[@gall2022]:

• MSH6 mutations cause Lynch syndrome
• Autosomal dominant inheritance
• Colorectal, endometrial cancer risk
• Variable penetrance

Alzheimer's Disease

In AD:

• Impaired MMR in neurons
• Accumulation of somatic mutations
• Microsatellite instability
• Therapeutic implications

Parkinson's Disease

In PD:

• DNA repair deficits
• Neuronal vulnerability
• Environmental interactions

Cancer

In sporadic tumors:

• MSH6 mutations in some cancers
• Microsatellite instability
• Therapeutic response (PD-1 blockade)

Expression Pattern

| Tissue | Expression | Notes |
|--------|------------|-------|
| Proliferating cells | High | Cell cycle dependent |
| [Neurons](/entities/neurons) | Moderate | Post-mitotic function |
| Most tissues | Moderate | Housekeeping |

Therapeutic Targeting

| Strategy | Approach | Status | Notes |
|----------|----------|--------|-------|
| Immunotherapy | MSI-H tumors | Approved | PD-1 inhibitors |
| Synthetic lethality | PARP inhibitors | Research | Combination therapy |

Background

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.

See Also

• [MSH6 Gene — MSH6 gene](/genes/msh6)
• [MSH2 Protein — Partner protein](/genes/ar)
• [DNA Repair — Repair pathways](/genes/th)
• [Lynch Syndrome — Hereditary cancer](/diseases/cancer)

External Links

• [UniProt: MSH6](https://www.uniprot.org/uniprot/P53271)
• [NCBI Gene: MSH6](https://www.ncbi.nlm.nih.gov/gene/2953)

References

[Li GM, et al, Mechanisms and functions of DNA mismatch repair (2023)](https://pubmed.ncbi.nlm.nih.gov/36628692/)

[Kunkel TA, et al, Mismatch repair (2022)](https://pubmed.ncbi.nlm.nih.gov/35077540/)

[Gall A, et al, MSH6 mutations in Lynch syndrome (2022)](https://pubmed.ncbi.nlm.nih.gov/35690023/)