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| Fc fragment of IgG, high affinity Ia, receptor (CD64) | |
|---|---|
| Identifiers | |
| Symbol | FCGR1A |
| Entrez | 2209 |
| HUGO | 3613 |
| OMIM | 146760 |
| RefSeq | NM_000566 |
| UniProt | P12314 |
| Other data | |
| Locus | Chr. 1 q21.2-21.3 |
| Fc fragment of IgG, high affinity Ib, receptor (CD64) | |
|---|---|
| Identifiers | |
| Symbol | FCGR1B |
| Entrez | 2210 |
| HUGO | 3614 |
| OMIM | 601502 |
| RefSeq | NM_001004340 |
| UniProt | Q92637 |
| Other data | |
| Locus | Chr. 1 p11.2 |
| Fc fragment of IgG, high affinity Ic, receptor (CD64) | |
|---|---|
| Identifiers | |
| Symbol | FCGR1C |
| Entrez | 2211 |
| HUGO | 3615 |
| OMIM | 601503 |
| RefSeq | XM_001133198 |
| Other data | |
| Locus | Chr. 1 q21.1 |
CD64 (Cluster of Differentiation 64) is a type of integral membrane glycoprotein known as an Fc receptor that binds monomeric IgG-type antibodies with high affinity.[1] It is more commonly known as Fc-gamma receptor 1 (FcγRI). After binding IgG, CD64 interacts with an accessory chain known as the common γ chain (γ chain), which possesses an ITAM motif that is necessary for triggering cellular activation.[2]
Structurally CD64 is composed of a signal peptide that allows its transport to the surface of a cell, three extracellular immunoglobulin domains of the C2-type that it uses to bind antibody, a hydrophobic transmembrane domain, and a short cytoplasmic tail.[3]
CD64 is constitutively found on only macrophages and monocytes, but treatment of polymorphonuclear leukocytes with cytokines like IFNγ and G-CSF can induce CD64 expression on these cells.[4][5]
There are three distinct (but highly similar) genes in humans for CD64 called FcγRIA (CD64A), FcγRIB (CD64B), and FcγRIC (CD64C) that are located on chromosome 1.[6] These three genes produce six different mRNA transcripts; two from CD64A, three from CD64B, and one from CD64C; by alternate splicing of the genes.[3]