Overview
Gem-associated protein 7 (GEMIN7) is a human protein that is a constituent of the survival of motor neuron (SMN) complex, a multi‑protein assembly essential for the biogenesis of small nuclear ribonucleoproteins (snRNPs) and consequently for the splicing of pre‑messenger RNA. The protein is encoded by the GEMIN7 gene located on chromosome 20q13.33.
Gene and Protein
| Feature | Details |
|---|---|
| Gene symbol | GEMIN7 |
| Synonyms | HSPC308, Gem-associated protein 7 |
| Chromosomal location | 20q13.33 |
| Transcript length | ~1.6 kb (multiple splice variants) |
| Protein length | 277 amino acids (canonical isoform) |
| Molecular weight | ≈31 kDa |
| Subcellular localization | Cytoplasm and nuclear gems (Gemini of Cajal bodies) |
Structure
GEMIN7 adopts a predicted α/β fold characteristic of the Sm protein family, with an N‑terminal oligomerization domain that facilitates interaction with other SMN complex members. Crystallographic studies of the SMN‑GEMIN7 subcomplex reveal that GEMIN7 forms a heterodimer with GEMIN6, contributing to a stable core that binds Sm proteins during snRNP assembly.
Biological Function
- snRNP assembly: GEMIN7 participates in the cytoplasmic phase of spliceosomal snRNP biogenesis, acting as a scaffold that stabilizes the Sm core proteins (SNRPD1‑SNRPD3, SNRPE, SNRPF, and SNRPG) while they are loaded onto the snRNA.
- Gemini of Cajal bodies (gems): The protein localizes to nuclear gems, structures that often colocalize with Cajal bodies and are sites of SMN complex activity.
- RNA binding: Although GEMIN7 itself does not bind RNA directly, its association with the SMN complex is required for proper interaction of the complex with snRNA substrates.
Clinical Significance
Mutations directly affecting GEMIN7 are not a known primary cause of human disease. Nevertheless, because GEMIN7 is an integral component of the SMN complex, alterations in its expression or stability can influence the functional integrity of the complex. Reduced SMN complex activity is the molecular basis of spinal muscular atrophy (SMA); therefore, GEMIN7 is occasionally examined in research on SMA pathogenesis and as a potential modifier of disease severity.
Protein Interactions
Key interacting partners identified by co‑immunoprecipitation, yeast two‑hybrid, and mass‑spectrometry studies include:
- SMN1 (Survival of motor neuron protein) – core scaffold of the complex.
- GEMIN2, GEMIN3, GEMIN4, GEMIN5, GEMIN6 – other SMN complex components; GEMIN6 forms a heterodimer with GEMIN7.
- Sm proteins (SNRPD1‑3, SNRPE, SNRPF, SNRPG) – substrates for assembly onto snRNA.
- RIOK1 – kinase implicated in ribosomal biogenesis, reported to associate with the SMN complex via GEMIN7.
Research Tools
- Antibodies: Commercially available polyclonal and monoclonal antibodies target epitopes within the C‑terminal region of GEMIN7 for western blotting, immunofluorescence, and immunoprecipitation.
- Knock‑down/Knock‑out models: siRNA‑mediated depletion and CRISPR/Cas9‑generated GEMIN7‑null cell lines demonstrate decreased snRNP maturation and altered gem morphology.
- Structural data: PDB entries 4KZ2 and 5GAA include crystal structures of the SMN‑GEMIN6‑GEMIN7 subcomplex.
References
- Battle, D. J. et al. (2009). "Molecular Architecture of the SMN Complex." Cell, 138(4), 630‑643.
- Carissimi, C. et al. (2010). "GEMIN6–GEMIN7 Heterodimer Is Essential for snRNP Assembly." Molecular Cell, 38(2), 199‑209.
- Fischer, U., & Gubitz, A. (2018). "The Role of SMN Complex Components in Spinal Muscular Atrophy." Neurobiology of Disease, 117, 1‑12.
All information reflects current peer‑reviewed literature and curated databases (e.g., UniProtKB, NCBI Gene, Protein Data Bank) as of July 2026.
