NBS1 Protein

NBS1 Protein

Overview

<table class="infobox infobox-protein">
<tr>
<th class="infobox-header" colspan="2">NBS1 Protein</th>
</tr>
<tr>
<td class="label">Symbol</td>
<td><strong>NBS1</strong></td>
</tr>
<tr>
<td class="label">Full Name</td>
<td>NBS1</td>
</tr>
<tr>
<td class="label">Type</td>
<td>Protein</td>
</tr>
<tr>
<td class="label">UniProt</td>
<td><a href="https://www.uniprot.org/uniprot/?query=NBS1" target="_blank">Search UniProt</a></td>
</tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/als" style="color:#ef9a9a">Als</a>, <a href="/wiki/ataxia" style="color:#ef9a9a">Ataxia</a>, <a href="/wiki/cancer" style="color:#ef9a9a">Cancer</a>, <a href="/wiki/ms" style="color:#ef9a9a">Ms</a>, <a href="/wiki/senescence" style="color:#ef9a9a">Senescence</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">25 edges</a></td>
</tr>
</table>

NBS1 (Nijmegen Breakage Syndrome 1), also known as nibrin, is a key protein in the DNA damage response (DDR) machinery. As part of the MRN complex (MRE11-RAD50-NBS1), NBS1 senses DNA double-strand breaks (DSBs), activates ATM kinase signaling, and facilitates DNA repair. Given the high metabolic activity and post-mitotic nature of [neurons](/entities/neurons), proper DNA repair is critical for neuronal survival, making NBS1 relevant to neurodegenerative disease research[1][2].

Protein Structure and Function

NBS1 Protein

Overview

<table class="infobox infobox-protein">
<tr>
<th class="infobox-header" colspan="2">NBS1 Protein</th>
</tr>
<tr>
<td class="label">Symbol</td>
<td><strong>NBS1</strong></td>
</tr>
<tr>
<td class="label">Full Name</td>
<td>NBS1</td>
</tr>
<tr>
<td class="label">Type</td>
<td>Protein</td>
</tr>
<tr>
<td class="label">UniProt</td>
<td><a href="https://www.uniprot.org/uniprot/?query=NBS1" target="_blank">Search UniProt</a></td>
</tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/als" style="color:#ef9a9a">Als</a>, <a href="/wiki/ataxia" style="color:#ef9a9a">Ataxia</a>, <a href="/wiki/cancer" style="color:#ef9a9a">Cancer</a>, <a href="/wiki/ms" style="color:#ef9a9a">Ms</a>, <a href="/wiki/senescence" style="color:#ef9a9a">Senescence</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">25 edges</a></td>
</tr>
</table>

NBS1 (Nijmegen Breakage Syndrome 1), also known as nibrin, is a key protein in the DNA damage response (DDR) machinery. As part of the MRN complex (MRE11-RAD50-NBS1), NBS1 senses DNA double-strand breaks (DSBs), activates ATM kinase signaling, and facilitates DNA repair. Given the high metabolic activity and post-mitotic nature of [neurons](/entities/neurons), proper DNA repair is critical for neuronal survival, making NBS1 relevant to neurodegenerative disease research[1][2].

Protein Structure and Function

NBS1 is a 754-amino acid protein encoded by the NBN gene (formerly NBS1). It contains multiple functional domains: [@chrzanowska2012]

• Forkhead-associated (FHA) domain: Protein-protein interactions
• BRCT domains: DNA binding and checkpoint signaling
• N-terminal region: Interaction with MRE11

Role in the Nervous System

Neuronal DNA Repair

Neurons are highly metabolic cells with long life spans, requiring robust DNA repair mechanisms to maintain genomic integrity. The MRN complex is essential for repairing DNA damage from oxidative stress, a constant challenge in the brain. NBS1 deficiency leads to accumulation of DNA damage in neurons and progressive neurodegeneration.

ATM Activation

Following DNA damage, NBS1 recruits and activates ATM kinase, which phosphorylates downstream targets including p53, H2AX, and checkpoint kinases. This cascade leads to cell cycle arrest, DNA repair, or [apoptosis](/entities/apoptosis). Defective ATM-NBS1 signaling contributes to neuronal death in various conditions.

Synaptic Function

Emerging evidence suggests NBS1 has functions at synapses, where it may participate in DNA repair within neuronal processes and contribute to synaptic plasticity.

Disease Associations

Nijmegen Breakage Syndrome

This autosomal recessive disorder caused by NBS1 mutations features:

• Microcephaly
• Dysmorphic facial features
• Immunodeficiency
• Predisposition to lymphoid malignancies
• Progressive neurological deterioration

Alzheimer's Disease

NBS1 and the MRN complex are dysregulated in Alzheimer's disease brains. DNA damage accumulates in AD neurons, and impaired NBS1 function may contribute to this process. The protein interacts with [amyloid-beta](/proteins/amyloid-beta) and [tau](/proteins/tau) pathology in complex ways.

Parkinson's Disease

DNA damage accumulates in dopaminergic neurons in PD. NBS1-mediated DNA repair pathways may be compromised, contributing to neuronal vulnerability. Studies show altered NBS1 expression in PD models.

Ataxia-Telangiectasia-Like Disease

Some NBS1 mutations cause ATLD (ataxia-telangiectasia-like disease), a condition with overlapping features including cerebellar ataxia and increased cancer risk.

Therapeutic Implications

Modulating NBS1 function and the broader DNA damage response represents a therapeutic strategy for neurodegenerative diseases. Approaches include:

• Enhancing DNA repair capacity
• Reducing DNA damage burden
• Targeting downstream apoptotic pathways

See Also

• [DNA Damage Response](/mechanisms/dna-damage-response)
• [Ataxia-Telangiectasia](/diseases/ataxia-telangiectasia)
• [MRN Complex](/mechanisms/mrn-complex)
• [ATM Kinase](/proteins/atm-protein)
• [Alzheimer's Disease](/diseases/alzheimers-disease)

References