FCGR1A
Fc Gamma Receptor Ia (CD64)
Gene Information Card
| Symbol | FCGR1A |
|---|---|
| Full Name | Fc Gamma Receptor Ia |
| Gene Type | protein-coding |
| Chromosomal Location | 1q21.2 |
| NCBI Gene ID | 2209 ncbi.nlm.nih.gov/gene/2209 |
| Ensembl ID | ENSG00000150337 |
| UniProt ID | P12314 |
| OMIM ID | 146760 |
| HGNC ID | 3613 |
| Aliases | CD64, FcgammaRI, FcRI, IGFR1 |
Description
FCGR1A encodes the high-affinity Fc gamma receptor Ia (CD64), a transmembrane glycoprotein expressed on macrophages, monocytes, and activated neutrophils. It binds the Fc region of IgG with high affinity and mediates phagocytosis, antibody-dependent cellular cytotoxicity (ADCC), and cytokine release. FCGR1A plays a critical role in immune defense against pathogens and is implicated in autoimmune diseases and inflammatory disorders.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Rheumatoid Arthritis | FCGR1A overexpression on synovial macrophages enhances IgG immune complex uptake, driving pro-inflammatory cytokine release. | ClinVar, OMIM |
| Systemic Lupus Erythematosus | Increased FCGR1A expression on monocytes promotes clearance of IgG-containing immune complexes, contributing to tissue inflammation. | ClinVar, OMIM |
| Infectious Diseases (e.g., tuberculosis) | FCGR1A mediates phagocytosis of IgG-opsonized pathogens; polymorphisms may affect susceptibility. | NCBI Gene, OMIM |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Whole blood | 12.5 | High |
| Spleen | 8.3 | Medium |
| Lung | 6.1 | Medium |
| Bone marrow | 5.4 | Medium |
| Liver | 2.1 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| Monocytes (THP-1) | 15.2 | High expression; used in ADCC assays |
| Macrophages (differentiated) | 18.7 | High expression; key for phagocytosis |
| Neutrophils (activated) | 9.8 | Induced upon activation |
| B lymphocytes (Raji) | 0.5 | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.497A>G (p.Asn166Ser) | missense | <0.1% | May alter IgG binding affinity; reported in autoimmune cohorts |
| c.1123G>A (p.Gly375Arg) | missense | <0.1% | Potential impact on receptor dimerization |
| c.1-9C>T | intronic | 0.2% | Associated with altered expression levels in monocytes |
Mutation functional classification
Loss of Function (LOF)
Loss-of-function mutations in FCGR1A are rare; they impair IgG binding and phagocytosis, increasing susceptibility to bacterial infections.
Gain of Function (GOF)
Gain-of-function variants (e.g., promoter polymorphisms) increase receptor expression, linked to enhanced inflammatory responses in autoimmune diseases.
Dominant Negative (DN)
No dominant-negative mutations have been reported for FCGR1A.
View complete mutation data：
Gene Ontology (GO)
| • Fc-gamma receptor I complex | • IgG binding |
| • phagocytosis | • antibody-dependent cellular cytotoxicity |
| • signal transduction | • cell surface receptor signaling pathway |
| • innate immune response | • positive regulation of cytokine production |
Pathways
• Fc gamma receptor-mediated phagocytosis (KEGG: hsa04666)
• Fc epsilon RI signaling pathway (KEGG: hsa04664)
• Natural killer cell mediated cytotoxicity (KEGG: hsa04650)
• Immune System (Reactome: R-HSA-168256)
Protein Summary
FCGR1A encodes the high-affinity Fc gamma receptor Ia (CD64), a 72 kDa transmembrane protein with three extracellular immunoglobulin-like domains. It binds monomeric IgG with high affinity (Ka ~10^8 M^-1) and is constitutively expressed on macrophages, monocytes, and activated neutrophils. Upon IgG binding, FCGR1A triggers ITAM-mediated signaling via the associated FcR gamma chain, leading to phagocytosis, ADCC, and pro-inflammatory cytokine release. CD64 is a key marker for monocyte/macrophage lineage and is upregulated in inflammatory conditions.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| FCGR1A Knockout HEK293 Cell Line | EDJ-KQ50267 | Human | 2209 | Details Get a Quote |
| FCGR1A Knockout HeLa Cell Line | EDJ-KQ53207 | Human | 2209 | Details Get a Quote |
| FCGR1A Knockout A-549 Cell Line | EDJ-KQ61688 | Human | 2209 | Details Get a Quote |
| FCGR1A Knockout HCT 116 Cell Line | EDJ-KQ70174 | Human | 2209 | Details Get a Quote |
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