SUSD4: Sushi Domain Containing 4 – A Complement Regulator and Immune Modulator
Comprehensive genomic and functional analysis of SUSD4, a gene encoding a sushi domain-containing protein involved in complement regulation and potential tumor suppression.
Gene Information Card
| Symbol | SUSD4 |
|---|---|
| Full Name | Sushi Domain Containing 4 |
| Gene Type | Protein coding |
| Chromosomal Location | 1q41 |
| NCBI Gene ID | 55061 ncbi.nlm.nih.gov/gene/55061 |
| Ensembl ID | ENSG00000143515 |
| UniProt ID | Q5VX71 |
| OMIM ID | 617527 |
| HGNC ID | 25407 |
| Aliases | FLJ11029, MGC131851, dJ1181N3.1 |
Description
SUSD4 (Sushi Domain Containing 4) encodes a protein with sushi domains (also known as complement control protein modules) that is involved in the regulation of the complement system. The protein is anchored to the cell membrane via a glycosylphosphatidylinositol (GPI) linkage and acts as a negative regulator of complement activation by binding C1q and inhibiting the classical pathway. SUSD4 is expressed in various tissues, with notable levels in the brain, and has been implicated in immune modulation and tumor suppression. Loss of SUSD4 expression is observed in several cancers, suggesting a potential role as a tumor suppressor.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Colorectal cancer | Downregulation of SUSD4 leads to increased complement activation and tumor-promoting inflammation | PMID: 25944712 |
| Breast cancer | Reduced SUSD4 expression correlates with poor prognosis and immune evasion | PMID: 31073040 |
| Glioma | SUSD4 methylation and silencing associated with tumor progression | PMID: 29348694 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain | 12.5 | Medium |
| Lung | 8.3 | Low |
| Liver | 6.1 | Low |
| Kidney | 9.7 | Low |
| Testis | 15.2 | Medium |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK 293 | 18.4 | Embryonic kidney cells |
| SH-SY5Y | 22.1 | Neuroblastoma cell line |
| HCT 116 | 5.3 | Colorectal carcinoma |
| MCF7 | 7.8 | Breast cancer cell line |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1015C>T (p.Arg339*) | Nonsense | 0.02% (gnomAD) | Premature truncation, loss of function |
| c.724G>A (p.Gly242Ser) | Missense | 0.01% (gnomAD) | Unknown significance |
| c.1234_1235insA (p.Thr412Asnfs*5) | Frameshift | Reported in COSMIC | Loss of function in colorectal cancer |
Mutation functional classification
Loss of Function (LOF)
Nonsense and frameshift mutations (e.g., p.Arg339*, p.Thr412Asnfs*5) result in truncated or degraded protein, leading to loss of complement regulatory activity.
Gain of Function (GOF)
No gain-of-function mutations have been reported for SUSD4.
Dominant Negative (DN)
No dominant-negative mutations have been characterized for SUSD4.
View complete mutation data：
Gene Ontology (GO)
| • complement binding (GO:0001848) | • plasma membrane (GO:0005886) |
| • complement activation (GO:0006956) | • regulation of complement activation (GO:0030449) |
| • innate immune response (GO:0045087) |
Pathways
• Complement cascade (Reactome: R-HSA-166658)
• Regulation of complement activation (Reactome: R-HSA-977606)
Protein Summary
SUSD4 is a GPI-anchored membrane protein containing sushi domains that bind C1q and inhibit the classical complement pathway. It is expressed in multiple tissues, especially the brain and testis, and plays a role in immune homeostasis. Reduced expression in cancers suggests a tumor-suppressive function through modulation of complement-mediated inflammation.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| SUSD4 Knockout HEK293 Cell Line | EDJ-KQ15571 | Human | 55061 | Details Get a Quote |
| SUSD4 Knockout HCT 116 Cell Line | EDJ-KQ46435 | Human | 55061 | Details Get a Quote |
| SUSD4 Knockout HeLa Cell Line | EDJ-KQ56528 | Human | 55061 | Details Get a Quote |
| SUSD4 Knockout A-549 Cell Line | EDJ-KQ65022 | Human | 55061 | Details Get a Quote |
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