RIPK2 Protein

RIPK2 Protein — Receptor-Interacting Serine/Threonine-Protein Kinase 2

<div class="infobox infobox-protein">
<table>
<tr><th colspan="2" style="background:#e8f4f8; text-align:center; font-size:1.1em;">RIPK2 Protein</th></tr>
<tr><td><strong>Protein Name</strong></td><td>Receptor-Interacting Serine/Threonine-Protein Kinase 2</td></tr>
<tr><td><strong>Gene</strong></td><td>[RIPK2](/genes/ripk2)</td></tr>
<tr><td><strong>UniProt ID</strong></td><td>[O43353](https://www.uniprot.org/uniprot/O43353)</td></tr>
<tr><td><strong>PDB ID</strong></td><td>1k3m, 4a2c, 5w5z</td></tr>
<tr><td><strong>Molecular Weight</strong></td><td>61 kDa</td></tr>
<tr><td><strong>Subcellular Localization</strong></td><td>Cytoplasm, Cytoskeleton</td></tr>
<tr><td><strong>Protein Family</strong></td><td>RIP kinase family</td></tr>
<tr><td><strong>Tissue Expression</strong></td><td>High in immune cells, brain, spinal cord</td></tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/als" style="color:#ef9a9a">Als</a>, <a href="/wiki/alzheimer" style="color:#ef9a9a">Alzheimer</a>, <a href="/wiki/amyotrophic-lateral-sclerosis" style="color:#ef9a9a">Amyotrophic Lateral Sclerosis</a>, <a href="/wiki/cancer" style="color:#ef9a9a">Cancer</a>, <a href="/wiki/carcinoma" style="color:#ef9a9a">Carcinoma</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">170 edges</a></td>
</tr>
</table>
</div>

Overview

RIPK2 Protein — Receptor-Interacting Serine/Threonine-Protein Kinase 2

<div class="infobox infobox-protein">
<table>
<tr><th colspan="2" style="background:#e8f4f8; text-align:center; font-size:1.1em;">RIPK2 Protein</th></tr>
<tr><td><strong>Protein Name</strong></td><td>Receptor-Interacting Serine/Threonine-Protein Kinase 2</td></tr>
<tr><td><strong>Gene</strong></td><td>[RIPK2](/genes/ripk2)</td></tr>
<tr><td><strong>UniProt ID</strong></td><td>[O43353](https://www.uniprot.org/uniprot/O43353)</td></tr>
<tr><td><strong>PDB ID</strong></td><td>1k3m, 4a2c, 5w5z</td></tr>
<tr><td><strong>Molecular Weight</strong></td><td>61 kDa</td></tr>
<tr><td><strong>Subcellular Localization</strong></td><td>Cytoplasm, Cytoskeleton</td></tr>
<tr><td><strong>Protein Family</strong></td><td>RIP kinase family</td></tr>
<tr><td><strong>Tissue Expression</strong></td><td>High in immune cells, brain, spinal cord</td></tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/als" style="color:#ef9a9a">Als</a>, <a href="/wiki/alzheimer" style="color:#ef9a9a">Alzheimer</a>, <a href="/wiki/amyotrophic-lateral-sclerosis" style="color:#ef9a9a">Amyotrophic Lateral Sclerosis</a>, <a href="/wiki/cancer" style="color:#ef9a9a">Cancer</a>, <a href="/wiki/carcinoma" style="color:#ef9a9a">Carcinoma</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">170 edges</a></td>
</tr>
</table>
</div>

Overview

RIPK2 Protein — Receptor-Interacting Serine/Threonine-Protein Kinase 2 is a key mediator of innate immune signaling that plays a critical role in neuroinflammation, a hallmark of neurodegenerative diseases including Alzheimer's disease (AD) and Parkinson's disease (PD)[@ripk2019]. RIPK2 transduces signals from NOD1 and NOD2 pattern recognition receptors, leading to [NF-κB](/entities/nf-kb) activation, MAPK signaling, and inflammatory gene expression. This page describes its structure, normal nervous system function, role in neurodegenerative disease, and potential as a therapeutic target.

Structure

RIPK2 is a 540-amino acid serine/threonine kinase with distinct structural domains:

• N-terminal kinase domain (1-300 aa): Contains activation loop and ATP-binding site, responsible for catalytic activity
• Intermediate region (300-400 aa): Contains regulatory motifs
• C-terminal CARD domain (400-540 aa): Caspase Recruitment Domain for protein-protein interactions

• Lacks death domain (unlike RIPK1)
• Contains unique CARD domain for signaling specificity
• Undergoes autophosphorylation upon activation at Ser176
• Kinase domain shows selectivity for RIPK2 over RIPK1 inhibitors

Normal Function

RIPK2 is a master regulator of innate immune signaling with multiple roles in the nervous system:

Immune Signaling

• NOD receptor signaling: Mediates NOD1/NOD2 inflammatory responses to intracellular bacterial peptides [@nod2018]
• NF-κB activation: Triggers pro-inflammatory gene expression (TNF-α, IL-1β, IL-6)[@targeting2021]
• MAPK signaling: Activates JNK and p38 pathways [@targeting2021]
• [Autophagy](/entities/autophagy) regulation: Regulates xenophagy and antibacterial defenses [@ripk2021]
• T-cell activation: Costimulatory signaling in T-cells

Neuroprotective Functions

• Microglial surveillance: Maintains baseline microglial activity
• CNS immune homeostasis: Regulates neuroinflammation magnitude
• Injury response: Mediates responses to CNS injury

Role in Neurodegenerative Disease

RIPK2 sits at the intersection of innate immunity and neurodegeneration, with growing evidence for its role in multiple conditions:

Alzheimer's Disease

In Alzheimer's disease, RIPK2 mediates neuroinflammation through multiple pathways [@targeting2021]:

The kinase activity of RIPK2 is elevated in AD brain tissue, particularly in microglia surrounding amyloid plaques [@ripk2020].

Parkinson's Disease

RIPK2 contributes to Parkinson's disease pathogenesis through [@nodripk2022]:

Other Neurodegenerative Conditions

• Multiple sclerosis: RIPK2 is implicated in demyelination and disease progression
• Amyotrophic lateral sclerosis (ALS): Elevated RIPK2 in microglia and [astrocytes](/entities/astrocytes)
• Frontotemporal dementia: RIPK2-mediated inflammation in microglial pathology
• Huntington's disease: RIPK2 contributes to inflammatory responses

Mechanism of Action

Therapeutic Targeting

RIPK2 is an emerging therapeutic target for neurodegenerative diseases:

Kinase Inhibitors

• Selectivity challenge: Developing RIPK2-selective inhibitors over RIPK1
• WEHI-345: Preclinical inhibitor showing anti-inflammatory effects
• Glibenclamide: FDA-approved drug with off-target RIPK2 activity

Anti-inflammatory Strategies

• NOD2-RIPK2 axis modulation: Targeting the upstream activator
• Combination therapy: RIPK2 + [NLRP3](/entities/nlrp3-inflammasome) or RIPK1 inhibition
• Microglial targeting: Cell-specific delivery

Clinical Considerations

• Peripheral vs CNS: [Blood-brain barrier](/entities/blood-brain-barrier) penetration challenges
• Immune suppression risk: Balancing anti-inflammatory effects with infection risk
• Biomarkers: RIPK2 activity markers in CSF

Dosing and Formulation

No approved RIPK2-targeted therapies exist for neurodegeneration. Research compounds:

| Compound | Stage | Notes |
|----------|-------|-------|
| WEHI-345 | Preclinical | RIPK2 kinase inhibitor |
| 4E1R | Preclinical | NOD2-RIPK2 inhibitor |
| Gliclazide | Approved (diabetes) | Off-target RIPK2 inhibition |

Safety and Contraindications

Potential concerns for RIPK2-targeted approaches:

• Immunodeficiency: NOD2-RIPK2 pathway is important for immune defense
• Infection risk: Increased susceptibility to intracellular bacteria
• GI inflammation: NOD2-RIPK2 in gut immune function

See Also

• [RIPK1 Protein](/proteins/ripk1-protein)
• [RIPK3 Protein](/proteins/ripk3-protein)
• NOD2 Protein
• [NLRP3 Inflammasome](/mechanisms/nlrp3-inflammasome) [Neuroinflammation](/mechanisms/neuroinflammation-pathway)
• [Microglia](/cell-types/microglia)
• [Alzheimer's Disease](/diseases/alzheimers-disease)
• [Parkinson's Disease](/diseases/parkinsons-disease)

References