SMOC1 Gene: SPARC-Related Modular Calcium Binding 1
A matricellular protein involved in development, eye and limb formation, and tumor biology
Gene Information Card
| Symbol | SMOC1 |
|---|---|
| Full Name | SPARC-related modular calcium binding 1 |
| Gene Type | protein coding |
| Chromosomal Location | 14q24.2 |
| NCBI Gene ID | 64093 ncbi.nlm.nih.gov/gene/64093 |
| Ensembl ID | ENSG00000198732 |
| UniProt ID | Q9H4F8 |
| OMIM ID | 608488 |
| HGNC ID | 20318 |
| Aliases | SMAP-2, FLJ14008 |
Description
SMOC1 (SPARC-related modular calcium binding 1) encodes a secreted matricellular protein that belongs to the SPARC family. It contains an EF-hand calcium-binding domain, a thyroglobulin type-1 domain, and two follistatin-like domains. SMOC1 is involved in cell adhesion, migration, and proliferation, and plays critical roles in embryonic development, particularly in eye and limb formation. Mutations in SMOC1 are associated with microphthalmia with limb anomalies (MLA) and other developmental disorders. The gene is also implicated in cancer progression and fibrosis.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Microphthalmia with limb anomalies (MLA) | Biallelic loss-of-function mutations in SMOC1 disrupt normal eye and limb development, leading to microphthalmia and limb malformations. | OMIM #608488; ClinVar |
| Ocular coloboma | Heterozygous mutations in SMOC1 may contribute to coloboma, a congenital eye defect, through haploinsufficiency or dominant-negative effects. | ClinVar; literature |
| Cancer (various types) | SMOC1 expression is altered in several cancers (e.g., breast, ovarian, colorectal), affecting tumor growth and metastasis via modulation of extracellular matrix and signaling pathways. | COSMIC; PubMed |
| Fibrosis (e.g., renal, pulmonary) | SMOC1 is upregulated in fibrotic tissues and promotes fibroblast activation and extracellular matrix deposition. | PubMed |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Kidney | 12.4 | Medium |
| Liver | 8.2 | Low |
| Lung | 6.5 | Low |
| Brain | 4.1 | Low |
| Heart | 3.8 | Low |
| Testis | 2.9 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HepG2 (liver cancer) | 15.3 | High expression |
| A549 (lung cancer) | 9.8 | Moderate |
| MCF7 (breast cancer) | 7.2 | Moderate |
| HeLa (cervical cancer) | 5.1 | Low |
| K562 (leukemia) | 2.0 | Very low |
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.112C>T (p.Arg38*) | Nonsense | Rare | Premature truncation, loss of function |
| c.245delA (p.Asn82Ilefs*5) | Frameshift | Rare | Frameshift leading to premature stop, loss of function |
| c.400G>A (p.Gly134Arg) | Missense | Rare | Potential dominant-negative effect in coloboma |
| c.789+1G>T | Splice site | Rare | Splicing defect, likely loss of function |
Mutation functional classification
Loss of Function (LOF)
Most pathogenic mutations in SMOC1 are loss-of-function (nonsense, frameshift, splice site) leading to haploinsufficiency or null alleles, causing developmental defects like MLA.
Gain of Function (GOF)
No clear gain-of-function mutations reported; overexpression in cancer may act as oncogenic but not due to mutations.
Dominant Negative (DN)
Some missense mutations (e.g., p.Gly134Arg) may exert dominant-negative effects by interfering with protein-protein interactions, particularly in ocular coloboma.
View complete mutation data：
Gene Ontology (GO)
| • calcium ion binding | • extracellular matrix organization |
| • cell adhesion | • cell migration |
| • regulation of cell proliferation | • embryonic eye morphogenesis |
| • limb morphogenesis | • SMAD protein signal transduction |
| • BMP signaling pathway | • negative regulation of cell cycle |
Pathways
• BMP signaling pathway
• TGF-beta signaling pathway
• Integrin signaling pathway
• Extracellular matrix organization
Protein Summary
SMOC1 is a 436-amino acid secreted glycoprotein with a molecular weight of ~48 kDa. It contains a signal peptide, an EF-hand calcium-binding domain, a thyroglobulin type-1 domain, and two follistatin-like domains. The protein is involved in cell-matrix interactions and modulates growth factor signaling, particularly BMP and TGF-beta pathways. It is expressed in various tissues, with highest levels in kidney and liver. SMOC1 is essential for normal eye and limb development, and its dysregulation contributes to cancer and fibrosis.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| SMOC1 Knockout HEK293 Cell Line | EDJ-KQ12215 | Human | 64093 | Details Get a Quote |
| SMOC1 Knockout A-549 Cell Line | EDJ-KQ40957 | Human | 64093 | Details Get a Quote |
| SMOC1 Knockout HeLa Cell Line | EDJ-KQ40958 | Human | 64093 | Details Get a Quote |
| SMOC1 Knockout HCT 116 Cell Line | EDJ-KQ73962 | Human | 64093 | Details Get a Quote |
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