SIGLEC1 (Sialic Acid Binding Ig Like Lectin 1)
A macrophage-restricted adhesion molecule and biomarker for interferon activity in autoimmune diseases
Gene Information Card
| Symbol | SIGLEC1 |
|---|---|
| Full Name | Sialic Acid Binding Ig Like Lectin 1 |
| Gene Type | protein-coding |
| Chromosomal Location | 20p13 |
| NCBI Gene ID | 6614 ncbi.nlm.nih.gov/gene/6614 |
| Ensembl ID | ENSG00000101442 |
| UniProt ID | Q9BZZ2 |
| OMIM ID | 600751 |
| HGNC ID | 10875 |
| Aliases | CD169, SIGLEC-1, sialoadhesin, SN |
Description
SIGLEC1 encodes sialoadhesin (CD169), a type I transmembrane protein belonging to the sialic acid-binding immunoglobulin-like lectin (Siglec) family. It is predominantly expressed on subsets of macrophages, particularly in lymphoid tissues and inflammatory sites. SIGLEC1 mediates cell-cell interactions by recognizing sialic acid residues on glycoproteins and glycolipids, playing a key role in innate immunity, antigen capture, and regulation of interferon responses. Elevated expression is a hallmark of type I interferon activation and is used as a biomarker in systemic lupus erythematosus and other interferonopathies.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Systemic Lupus Erythematosus (SLE) | Overexpression of SIGLEC1 on monocytes/macrophages reflects type I interferon pathway activation; used as a biomarker for disease activity and response to therapy. | ClinVar, NCBI Gene, PubMed |
| Sjögren's Syndrome | Increased SIGLEC1 expression correlates with interferon signature and disease severity. | NCBI Gene, PubMed |
| Dermatomyositis | SIGLEC1 upregulation in peripheral blood monocytes associated with interferon-driven pathology. | PubMed |
| Viral Infections (e.g., HIV, SARS-CoV-2) | SIGLEC1 mediates viral entry and immune modulation; elevated expression during acute infection. | NCBI Gene, PubMed |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Spleen | 12.5 | Medium |
| Lymph Node | 10.8 | Medium |
| Lung | 8.2 | Medium |
| Bone Marrow | 6.1 | Low |
| Blood | 5.4 | Low |
| Liver | 4.7 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| Monocytes (CD14+) | 15.3 | High expression; interferon-inducible |
| Macrophages (M1 polarized) | 18.1 | High expression |
| Macrophages (M2 polarized) | 9.2 | Moderate expression |
| THP-1 (monocytic leukemia) | 12.0 | Inducible by interferon-alpha |
| U937 (histiocytic lymphoma) | 10.5 | Inducible by interferon-gamma |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1234C>T (p.Arg412Cys) | Missense | <0.01% | Unknown functional impact; rare population variant |
| c.567G>A (p.Trp189*) | Nonsense | <0.01% | Predicted loss of function; not associated with disease |
Mutation functional classification
Loss of Function (LOF)
Rare nonsense mutations (e.g., p.Trp189*) are predicted to cause loss of function, but no disease association has been established.
Gain of Function (GOF)
No gain-of-function mutations reported.
Dominant Negative (DN)
No dominant-negative mutations reported.
View complete mutation data：
Gene Ontology (GO)
| • cell adhesion | • receptor-mediated endocytosis |
| • innate immune response | • carbohydrate binding |
| • protein homodimerization activity | • macrophage activation |
Pathways
• Type I interferon signaling pathway
• Cell adhesion molecules (CAMs)
• Lysosome and phagosome pathway
Protein Summary
Sialoadhesin (CD169) is a 185 kDa transmembrane protein with 17 extracellular immunoglobulin-like domains and a short cytoplasmic tail containing a signaling motif. It binds sialic acid ligands on host and pathogen surfaces, facilitating cell-cell adhesion, antigen capture, and pathogen recognition. SIGLEC1 is a well-established marker of interferon-activated macrophages and is used clinically to monitor type I interferon activity in autoimmune diseases.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| SIGLEC15 Knockout HEK293 Cell Line | EDJ-KQ3254 | Human | 284266 | Details Get a Quote |
| SIGLEC1 Knockout HEK293 Cell Line | EDJ-KQ3899 | Human | 6614 | Details Get a Quote |
| SIGLEC11 Knockout HEK293 Cell Line | EDJ-KQ7439 | Human | 114132 | Details Get a Quote |
| SIGLEC12 Knockout HEK293 Cell Line | EDJ-KQ10525 | Human | 89858 | Details Get a Quote |
| SIGLEC16 Knockout HEK293 Cell Line | EDJ-KQ11580 | Human | 400709 | Details Get a Quote |
| SIGLEC14 Knockout HEK293 Cell Line | EDJ-KQ12154 | Human | 100049587 | Details Get a Quote |
| SIGLEC10 Knockout HEK293 Cell Line | EDJ-KQ17766 | Human | 89790 | Details Get a Quote |
| SIGLEC16 Knockout HCT 116 Cell Line | EDJ-KQ39917 | Human | 400709 | Details Get a Quote |
| SIGLEC16 Knockout HeLa Cell Line | EDJ-KQ38594 | Human | 400709 | Details Get a Quote |
| SIGLEC16 Knockout A-549 Cell Line | EDJ-KQ39916 | Human | 400709 | Details Get a Quote |
| Siglec15 Knockout MC-38 Cell Line | EDJ-KZ457 | Mouse | 284266 | Details Get a Quote |
| Siglec15 Knockout RAW 264.7 Cell Line | EDJ-KZ458 | Mouse | 620235 | Details Get a Quote |
| SIGLEC1 Knockout HeLa Cell Line | EDJ-KQ54531 | Human | 6614 | Details Get a Quote |
| SIGLEC10 Knockout HeLa Cell Line | EDJ-KQ57738 | Human | 89790 | Details Get a Quote |
| SIGLEC12 Knockout HeLa Cell Line | EDJ-KQ57743 | Human | 89858 | Details Get a Quote |
