| Fc fragment of IgG, high affinity Ia, receptor (CD64) | |
| Hgncid: | 3613 |
| Symbol: | FCGR1A |
| Entrezgene: | 2209 |
| Omim: | 146760 |
| Refseq: | NM_000566 |
| Uniprot: | P12314 |
| Chromosome: | 1 |
| Arm: | q |
| Band: | 21.2 |
| Locussupplementarydata: | -21.3 |
| Fc fragment of IgG, high affinity Ib, receptor (CD64) | |
| Hgncid: | 3614 |
| Symbol: | FCGR1B |
| Entrezgene: | 2210 |
| Omim: | 601502 |
| Refseq: | NM_001004340 |
| Uniprot: | Q92637 |
| Chromosome: | 1 |
| Arm: | p |
| Band: | 11.2 |
| Fc fragment of IgG, high affinity Ic, receptor (CD64) | |
| Hgncid: | 3615 |
| Symbol: | FCGR1C |
| Entrezgene: | 2211 |
| Omim: | 601503 |
| Refseq: | XM_001133198 |
| Chromosome: | 1 |
| Arm: | q |
| Band: | 21.1 |
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.