SMC1B
Structural Maintenance of Chromosomes 1B
Gene Information Card
| Symbol | SMC1B |
|---|---|
| Full Name | Structural Maintenance of Chromosomes 1B |
| Gene Type | Protein coding |
| Chromosomal Location | 22q13.33 |
| NCBI Gene ID | 27127 ncbi.nlm.nih.gov/gene/27127 |
| Ensembl ID | ENSG00000100219 |
| UniProt ID | Q8NDV3 |
| OMIM ID | 608685 |
| HGNC ID | 11112 |
| Aliases | SMC1L2, SMC1beta, SMC1B_HUMAN |
Description
SMC1B encodes a member of the structural maintenance of chromosomes (SMC) protein family, specifically a component of the meiotic cohesin complex. This protein is essential for sister chromatid cohesion, homologous recombination, and proper chromosome segregation during meiosis I. It forms a heterodimer with SMC3 and interacts with other cohesin subunits to establish and maintain cohesion between sister chromatids. SMC1B is predominantly expressed in testis and plays a critical role in spermatogenesis.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Premature Ovarian Failure 12 (POF12) | Loss-of-function mutations in SMC1B disrupt meiotic cohesin, leading to defective chromosome segregation and oocyte depletion. | OMIM #618023; PMID: 28552159 |
| Non-obstructive Azoospermia | Mutations impair meiotic progression, causing spermatogenic arrest and male infertility. | PMID: 28552159; PMID: 31006510 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 12.5 | High |
| Ovary | 2.1 | Low |
| Fallopian Tube | 1.0 | Low |
| Prostate | 0.8 | Low |
| Skin | 0.5 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| Spermatocytes | N/A | High expression in meiotic cells |
| Oocytes | N/A | Expressed during meiosis |
| HEK293 | 0.2 | Low expression |
| HeLa | 0.1 | Very low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.280C>T (p.Arg94*) | Nonsense | Rare | Loss of function; truncation of SMC1B protein |
| c.1093G>A (p.Gly365Arg) | Missense | Rare | Likely disrupts ATPase domain and cohesin loading |
| c.1756_1757del (p.Leu586fs) | Frameshift | Rare | Loss of function; premature termination |
Mutation functional classification
Loss of Function (LOF)
Nonsense and frameshift mutations lead to truncated or absent SMC1B protein, impairing meiotic cohesin complex assembly and function.
Gain of Function (GOF)
No gain-of-function mutations reported for SMC1B.
Dominant Negative (DN)
Missense mutations may exert dominant-negative effects by interfering with wild-type SMC1B incorporation into cohesin complexes.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Meiotic cohesin complex
• Cell cycle – meiosis
• Homologous recombination
Protein Summary
SMC1B is a 1230-amino-acid protein (UniProt Q8NDV3) that belongs to the SMC family. It contains an N-terminal globular domain, two coiled-coil regions, and a C-terminal hinge domain. The protein forms a V-shaped heterodimer with SMC3, which is central to the cohesin ring structure. SMC1B is specifically expressed during meiosis and is essential for chromosome cohesion and recombination. Its ATPase activity is required for dynamic loading and unloading of cohesin on chromosomes.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| SMC1B Knockout HEK293 Cell Line | EDJ-KQ2088 | Human | 27127 | Details Get a Quote |
| SMC1B Knockout HeLa Cell Line | EDJ-KQ56007 | Human | 27127 | Details Get a Quote |
| SMC1B Knockout A-549 Cell Line | EDJ-KQ64495 | Human | 27127 | Details Get a Quote |
| SMC1B Knockout HCT 116 Cell Line | EDJ-KQ72953 | Human | 27127 | Details Get a Quote |
