NLRC3 — NLR Family CARD Domain Containing 3

NLRC3 — NLR Family CARD Domain Containing 3

<div class="infobox infobox-gene">

| Property | Value | [@conti2005] |
|----------|-------| [@kortmann2015] |
| Gene Symbol | NLRC3 |
| Full Name | NLR Family CARD Domain Containing 3 |
| Chromosomal Location | 16p13.3 |
| NCBI Gene ID | 81128 |
| OMIM ID | 611362 |
| Ensembl ID | ENSG00000167900 |
| UniProt ID | Q7RTV0 |
| Encoded Protein | NLR family CARD domain-containing protein 3 |
| Associated Diseases | Cancer, Inflammatory Conditions, Alzheimer's Disease, Parkinson's Disease |

</div>

Overview

NLRC3 (NLR Family CARD Domain Containing 3), also known as NLR family CARD domain-containing protein 3 or NOD3, is a member of the NOD-like receptor (NLR) family of proteins. Located on chromosome 16p13.3, NLRC3 encodes a 755-amino acid protein that possesses unique structural features distinguishing it from other NLR family members. Unlike classical NLR proteins such as [NLRP3](/genes/nlrp3) or [NLRC4](/genes/nlrc4), NLRC3 contains a TIR (Toll/Interleukin-1 Receptor) domain, placing it at the intersection of NLR and TLR signaling pathways.

NLRC3 — NLR Family CARD Domain Containing 3

<div class="infobox infobox-gene">

| Property | Value | [@conti2005] |
|----------|-------| [@kortmann2015] |
| Gene Symbol | NLRC3 |
| Full Name | NLR Family CARD Domain Containing 3 |
| Chromosomal Location | 16p13.3 |
| NCBI Gene ID | 81128 |
| OMIM ID | 611362 |
| Ensembl ID | ENSG00000167900 |
| UniProt ID | Q7RTV0 |
| Encoded Protein | NLR family CARD domain-containing protein 3 |
| Associated Diseases | Cancer, Inflammatory Conditions, Alzheimer's Disease, Parkinson's Disease |

</div>

Overview

NLRC3 (NLR Family CARD Domain Containing 3), also known as NLR family CARD domain-containing protein 3 or NOD3, is a member of the NOD-like receptor (NLR) family of proteins. Located on chromosome 16p13.3, NLRC3 encodes a 755-amino acid protein that possesses unique structural features distinguishing it from other NLR family members. Unlike classical NLR proteins such as [NLRP3](/genes/nlrp3) or [NLRC4](/genes/nlrc4), NLRC3 contains a TIR (Toll/Interleukin-1 Receptor) domain, placing it at the intersection of NLR and TLR signaling pathways.

NLRC3 is expressed in various tissues, with highest expression in [immune cells](/cell-types/microglia) and epithelial tissues. It plays important roles in regulating [innate immune responses](/mechanisms/innate-immune-signaling), [inflammatory signaling](/mechanisms/neuroinflammation), [cell cycle regulation](/mechanisms/cell-cycle-regulation), and [DNA damage responses](/mechanisms/dna-damage-repair). Emerging research has revealed NLRC3 expression in [microglia](/cell-types/microglia) and [neurons](/cell-types/neurons), where it may modulate [neuroinflammatory responses](/mechanisms/neuroinflammation) relevant to [Alzheimer's Disease](/diseases/alzheimers-disease) and [Parkinson's Disease](/diseases/parkinsons-disease) pathogenesis.

Gene Structure and Evolution

The NLRC3 gene is located on chromosome 16p13.3 (positions 3,800,000-3,850,000, GRCh38) on the minus strand. The gene spans approximately 22 kb and comprises 14 exons that encode a 755-amino acid protein with a molecular weight of approximately 85 kDa.

Domain Architecture

NLRC3 contains several distinct functional domains:

The presence of the TIR domain is unique among NLR proteins and suggests distinct signaling mechanisms compared to other NLR family members.

Evolutionary Conservation

NLRC3 shows conservation across vertebrates:

| Species | Gene Name | Amino Acids | Function |
|---------|-----------|-------------|----------|
| Human | NLRC3 | 755 | Reference |
| Mouse | Nlrc3 | 752 | 78% identity |
| Zebrafish | nlrc3 | 738 | 52% identity |
| Chicken | NLRC3 | 749 | 75% identity |

Protein Structure and Function

Structural Features

NLRC3 possesses several unique structural characteristics:

Molecular Functions

NLRC3 participates in multiple cellular processes [@kortmann2015]:

Innate Immune Regulation

• Modulates [NF-κB signaling](/mechanisms/nf-kappa-b-pathway)
• Regulates [type I interferon responses](/mechanisms/interferon-signaling)
• Controls [inflammasome assembly](/mechanisms/inflammasome)

Cell Cycle Control

• Impacts [cell proliferation](/mechanisms/cell-cycle-regulation)
• Regulates [G1/S checkpoint](/mechanisms/cell-cycle-checkpoints)
• Controls [apoptosis](/mechanisms/apoptosis-pathways) pathways

DNA Damage Response

• As shown in [@cullin2017], NLRC3 localizes to sites of DNA damage
• Interacts with [ATM](/genes/atm) and [ATR](/genes/atr) signaling
• Contributes to [genomic stability](/mechanisms/dna-damage-repair)

Normal Physiological Functions

Immune System Functions

NLRC3 plays critical roles in [immune cell](/cell-types/microglia) function [@javierre2010]:

T Cell Regulation

• Modulates T cell activation thresholds
• Controls cytokine production
• Regulates T cell differentiation

Myeloid Cell Function

• Affects [macrophage](/cell-types/microglia) polarization
• Modulates [dendritic cell](/cell-types/dendritic-cells) maturation
• Regulates neutrophil responses

Stress Response

NLRC3 responds to various cellular stresses:

• ER stress: Modulates [unfolded protein response](/mechanisms/er-stress)
• Oxidative stress: Regulates [Nrf2 pathway](/mechanisms/oxidative-stress)
• DNA damage: Participates in [DNA repair](/mechanisms/dna-damage-repair) mechanisms

Tissue Homeostasis

In non-immune tissues, NLRC3 maintains:

• Epithelial integrity: Barrier function in gut and lung
• Metabolic regulation: Energy homeostasis
• Tissue repair: Regeneration responses

Disease Associations

Cancer

As characterized in [@zhang2021], NLRC3 shows tumor suppressor activity:

Tumor Suppression

• Loss of NLRC3 promotes tumorigenesis
• Lower expression in multiple cancer types
• Mutations identified in various malignancies

Molecular Mechanisms

• Modulates [p53 pathway](/mechanisms/p53-signaling)
• Regulates [cell cycle](/mechanisms/cell-cycle-regulation) checkpoints
• Controls [immune surveillance](/mechanisms/immune-surveillance)

Neurodegenerative Diseases

NLRC3 has emerging roles in [neurodegeneration](/diseases/alzheimers-disease) [@schneider2023]:

Alzheimer's Disease

• NLRC3 expressed in [brain microglia](/cell-types/microglia)
• Modulates [microglial activation](/mechanisms/microglial-activation)
• Regulates [TNF-α](/genes/tnfa) and [IL-1β](/genes/il1b) production

• NLRC3 dampens [NF-κB signaling](/mechanisms/nf-kappa-b-pathway) in brain
• Loss may contribute to [chronic neuroinflammation](/mechanisms/neuroinflammation)
• Potential impact on [β-amyloid](/mechanisms/amyloid-cascade) responses

• Altered expression in AD [brain](/brain-regions/hippocampus)
• Potential biomarker for disease progression
• Therapeutic target potential

Parkinson's Disease

• NLRC3 modulates [dopaminergic neuron](/cell-types/dopaminergic-neurons) inflammation
• May affect [α-synuclein](/proteins/alpha-synuclein)-induced toxicity
• Altered in PD brain regions

• Controls [microglial](/cell-types/microglia) polarization states
• Regulates [neuroinflammation](/mechanisms/neuroinflammation) magnitude
• Potential for therapeutic modulation

Autoimmune Conditions

• NLRC3 variants associated with autoimmune diseases
• Altered T cell function in autoimmunity
• Potential for diagnostic biomarker development

Expression Patterns

Tissue Distribution

NLRC3 shows broad but specific expression:

| Tissue | Expression Level | Notable Cell Types |
|--------|-----------------|-------------------|
| Lung | High | Epithelial cells, alveolar macrophages |
| Spleen | High | T cells, B cells, macrophages |
| Brain | Moderate | [Microglia](/cell-types/microglia), [neurons](/cell-types/neurons) |
| Intestine | Moderate | Intestinal epithelial cells |
| Heart | Low-moderate | Cardiomyocytes |
| Liver | Low | Hepatocytes |

Brain Expression

Within the [central nervous system](/brain-regions/cortex), NLRC3 is expressed in:

• Microglia: Primary immune cells expressing NLRC3
• Neurons: Lower but detectable expression
• Astrocytes: Some expression reported

Subcellular Localization

• Cytoplasm: Primary location
• Nucleus: Detected in some cell types
• Mitochondria: Associated with stress responses

Signaling Pathways

NF-κB Pathway

NLRC3 modulates the [NF-κB signaling pathway](/mechanisms/nf-kappa-b-pathway):

• Inhibits IKK complex activation
• Reduces IκB degradation
• Decreases NF-κB nuclear translocation

Type I Interferon Signaling

As a TIR domain-containing protein, NLRC3 interacts with:

• STING pathway: DNA virus responses
• TBK1/IRF3 axis: Type I interferon production
• RIG-I signaling: RNA virus detection

Inflammasome Regulation

Unlike [NLRP3](/genes/nlrp3), NLRC3 generally inhibits inflammasome activation:

• Prevents [NLRP3](/genes/nlrp3) inflammasome assembly
• Blocks [caspase-1](/genes/casp1) activation
• Reduces [IL-1β](/genes/il1b) and [IL-18](/genes/il18) production

Clinical Significance

Diagnostic Markers

NLRC3 expression may serve as:

• Cancer biomarker: Lower expression indicates poor prognosis
• Autoimmune marker: Altered in autoimmune conditions
• Neurodegenerative biomarker: Potential in AD/PD progression

Therapeutic Targeting

Current therapeutic strategies include:

• Small molecule activators of NLRC3
• Gene therapy to increase NLRC3 expression

• Targeting NLRC3 loss in tumors
• Synthetic lethal approaches

Research Directions

Unresolved Questions

Key questions remain:

Emerging Areas

• Single-cell analysis: Defining NLRC3 roles in specific [cell types](/cell-types/microglia)
• Structural biology: NLRC3-inhibitor complexes for drug design
• Systems biology: Network mapping of NLRC3 signaling

Interactions and Pathways

Protein-Protein Interactions

| Interactor | Interaction Type | Function |
|------------|-----------------|----------|
| MyD88 | TIR-TIR | TLR signaling adapter |
| NF-κB pathway | Modulation | Inhibits activation |
| p53 | Regulation | Cell cycle control |
| ATM/ATR | DNA damage | Genomic stability |

Genetic Interactions

• [NLRP3](/genes/nlrp3): Opposing functions in inflammasome regulation
• [NLRX1](/genes/nlrx1): Related NLR with distinct functions
• [TLR signaling](/mechanisms/tlr-signaling): TIR domain similarities

See Also

Related Pathways

• [NLR Signaling Pathway](/mechanisms/nlr-signaling)
• [Inflammasome Pathways](/mechanisms/inflammasome)
• [Neuroinflammation Mechanisms](/mechanisms/neuroinflammation)
• [NF-κB Pathway](/mechanisms/nf-kappa-b-pathway)
• [TLR Signaling Pathway](/mechanisms/tlr-signaling)

Related Diseases

• [Alzheimer's Disease](/diseases/alzheimers-disease)
• [Parkinson's Disease](/diseases/parkinsons-disease)
• [Cancer](/diseases/cancer)

Related Genes

• [NLRP3](/genes/nlrp3)
• [NLRC4](/genes/nlrc4)
• [NLRX1](/genes/nlrx1)
• [NLRP1](/genes/nlrp1)

External Links

• [Ensembl: ENSG00000167900](https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000167900)
• [NCBI Gene: NLRC3](https://www.ncbi.nlm.nih.gov/gene/81128)
• [GeneCards: NLRC3](https://www.genecards.org/cgi-bin/carddisp.pl?gene=NLRC3)
• [UniProt: Q7RTV0](https://www.uniprot.org/uniprot/Q7RTV0)
• [OMIM: 611362](https://omim.org/search?search=NLRC3)
• [STRING: NLRC3 Interactions](https://string-db.org/network/9606/ENSG00000167900)

References

Pathway Diagram

The following diagram shows the key molecular relationships involving nlrc3 discovered through SciDEX knowledge graph analysis: