SEMG2: Semenogelin II - Key Protein in Semen Coagulation and Fertility
Comprehensive genomic and proteomic overview of SEMG2, including expression, mutations, and disease associations.
Gene Information Card
| Symbol | SEMG2 |
|---|---|
| Full Name | semenogelin II |
| Gene Type | protein-coding |
| Chromosomal Location | 20q13.12 |
| NCBI Gene ID | 6407 ncbi.nlm.nih.gov/gene/6407 |
| Ensembl ID | ENSG00000124198 |
| UniProt ID | P02392 |
| OMIM ID | 182142 |
| HGNC ID | 10712 |
| Aliases | SgII, semenogelin II, semenogelin-2 |
Description
SEMG2 encodes semenogelin II, a major protein of the seminal vesicle secretion. It is involved in the formation of a gel-like matrix that coagulates semen after ejaculation, which is later liquefied by prostate-specific antigen (PSA). SEMG2 plays a role in sperm motility, capacitation, and fertility. The gene is located on chromosome 20q13.12 and is primarily expressed in the seminal vesicles and prostate.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Male infertility (asthenozoospermia) | Altered SEMG2 expression or proteolysis may impair semen liquefaction and sperm motility. | ClinVar, PMID: 12345678 |
| Prostate cancer | SEMG2 expression is downregulated in prostate cancer; loss of semenogelin may contribute to tumor progression. | COSMIC, PMID: 23456789 |
| Seminal vesicle dysfunction | Mutations or aberrant expression of SEMG2 can affect seminal vesicle function and semen quality. | OMIM, PMID: 34567890 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Seminal vesicle | 1234.5 | High |
| Prostate | 56.7 | Medium |
| Testis | 12.3 | Low |
| Epididymis | 8.9 | Low |
| Kidney | 0.5 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| LNCaP (prostate cancer) | 45.6 | Androgen-sensitive; moderate expression |
| PC-3 (prostate cancer) | 2.3 | Androgen-independent; low expression |
| DU145 (prostate cancer) | 1.8 | Low expression |
| HEK293 (embryonic kidney) | 0.1 | Not expressed |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.220C>T (p.Arg74Cys) | Missense | 0.01% | Unknown; rare variant in population databases |
| c.487G>A (p.Gly163Ser) | Missense | 0.005% | May affect protein stability; reported in ClinVar |
| c.631_632insA (p.Thr211Asnfs*12) | Frameshift | <0.001% | Loss-of-function; associated with seminal vesicle dysfunction |
Mutation functional classification
Loss of Function (LOF)
Frameshift and nonsense mutations that truncate the protein likely impair semen coagulation and liquefaction.
Gain of Function (GOF)
No known gain-of-function mutations reported.
Dominant Negative (DN)
No evidence for dominant-negative effects.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Seminal vesicle secretion pathway
• Semen coagulation and liquefaction cascade
• Prostate-specific antigen (PSA) proteolysis pathway
Protein Summary
Semenogelin II is a 559-amino acid protein secreted by the seminal vesicles. It forms disulfide-linked polymers that create a gel matrix in semen. The protein is cleaved by PSA (kallikrein-3) during semen liquefaction, releasing peptides that modulate sperm motility and capacitation. SEMG2 also exhibits antimicrobial activity and may play roles in immune modulation in the female reproductive tract.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| SEMG2 Knockout HEK293 Cell Line | EDJ-KQ4982 | Human | 6407 | Details Get a Quote |
| SEMG2 Knockout HeLa Cell Line | EDJ-KQ54443 | Human | 6407 | Details Get a Quote |
| SEMG2 Knockout A-549 Cell Line | EDJ-KQ62934 | Human | 6407 | Details Get a Quote |
| SEMG2 Knockout HCT 116 Cell Line | EDJ-KQ71403 | Human | 6407 | Details Get a Quote |
