C8G Gene - Complement C8 Gamma Chain
A key component of the membrane attack complex in the complement system
Gene Information Card
| Symbol | C8G |
|---|---|
| Full Name | Complement C8 Gamma Chain |
| Gene Type | Protein coding |
| Chromosomal Location | 9q34.3 |
| NCBI Gene ID | 733 ncbi.nlm.nih.gov/gene/733 |
| Ensembl ID | ENSG00000106927 |
| UniProt ID | P07360 |
| OMIM ID | 120930 |
| HGNC ID | 1354 |
| Aliases | C8G1, MGC149531, MGC149532 |
Description
The C8G gene encodes the gamma chain of complement component 8 (C8), a constituent of the membrane attack complex (MAC). C8 is a heterotrimer composed of alpha, beta, and gamma chains. The gamma chain is a member of the lipocalin family and is involved in the formation of the MAC, which mediates cell lysis by the complement system. C8G deficiency is associated with increased susceptibility to recurrent neisserial infections.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Complement component 8 deficiency | Loss-of-function mutations in C8G prevent formation of functional C8, impairing MAC assembly and lytic activity | OMIM #120930; ClinVar |
| Recurrent meningococcal infections | Deficiency of C8 leads to inability to lyse Neisseria meningitidis, increasing infection risk | OMIM #120930; PubMed studies |
| Systemic lupus erythematosus (SLE) | Complement deficiencies, including C8G, may contribute to immune complex clearance defects | Case reports in ClinVar |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Liver | 12.5 | Medium |
| Spleen | 8.3 | Medium |
| Blood | 6.1 | Low |
| Lung | 4.7 | Low |
| Kidney | 3.2 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HepG2 | 15.2 | Hepatocellular carcinoma cell line |
| K-562 | 2.1 | Chronic myelogenous leukemia |
| HeLa | 1.8 | Cervical adenocarcinoma |
| A549 | 1.5 | Lung carcinoma |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1A>G (p.Met1?) | Missense | Rare | Loss of start codon, likely loss of function |
| c.202C>T (p.Arg68*) | Nonsense | Rare | Premature stop, loss of function |
| c.485_486delAG (p.Glu162Valfs*5) | Frameshift | Rare | Frameshift, loss of function |
Mutation functional classification
Loss of Function (LOF)
Most reported C8G mutations are loss-of-function, leading to C8 deficiency and increased susceptibility to neisserial infections.
Gain of Function (GOF)
No gain-of-function mutations have been reported for C8G.
Dominant Negative (DN)
No dominant-negative effects have been described for C8G mutations.
View complete mutation data：
Gene Ontology (GO)
| • extracellular region (GO:0005576) | • membrane attack complex (GO:0005579) |
| • complement activation (GO:0006956) | • regulation of complement activation (GO:0030449) |
| • binding (GO:0005488) |
Pathways
• Complement cascade (KEGG: hsa04610)
• Staphylococcus aureus infection (KEGG: hsa05150)
• Tuberculosis (KEGG: hsa05152)
Protein Summary
The C8 gamma chain is a 22 kDa protein (182 amino acids) that belongs to the lipocalin family. It is synthesized in the liver and secreted into plasma, where it associates non-covalently with the C8 alpha and beta chains to form the C8 complex. The gamma chain is essential for the structural integrity of C8 and its incorporation into the membrane attack complex. Deficiency of C8G leads to impaired MAC formation and recurrent neisserial infections.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| C8G Knockout HEK293 Cell Line | EDJ-KQ4162 | Human | 733 | Details Get a Quote |
| C8G Knockout A-549 Cell Line | EDJ-KQ26603 | Human | 733 | Details Get a Quote |
| C8G Knockout HeLa Cell Line | EDJ-KQ26604 | Human | 733 | Details Get a Quote |
| C8G Knockout HCT 116 Cell Line | EDJ-KQ69719 | Human | 733 | Details Get a Quote |
