SAP18 (Sin3A Associated Protein 18)
A component of the Sin3/HDAC co-repressor complex involved in transcriptional regulation and RNA splicing.
Gene Information Card
| Symbol | SAP18 |
|---|---|
| Full Name | Sin3A Associated Protein 18 |
| Gene Type | Protein coding |
| Chromosomal Location | 13q12.11 |
| NCBI Gene ID | 10284 ncbi.nlm.nih.gov/gene/10284 |
| Ensembl ID | ENSG00000139618 |
| UniProt ID | O00422 |
| OMIM ID | 602949 |
| HGNC ID | 10530 |
| Aliases | SAP18P, SAP18A, SAP18B |
Description
SAP18 (Sin3A Associated Protein 18) encodes a protein that is a component of the Sin3/HDAC co-repressor complex. This complex mediates transcriptional repression by deacetylating histones and recruiting other repressive factors. SAP18 also plays a role in RNA splicing, interacting with the spliceosome and influencing alternative splicing events. The gene is ubiquitously expressed and is involved in cell cycle regulation, apoptosis, and development.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Cancer (various) | Dysregulation of SAP18 expression may alter transcriptional repression of tumor suppressor genes or oncogenes, contributing to tumorigenesis. | COSMIC, NCBI |
| Neurodevelopmental disorders | Mutations or altered expression of SAP18 may disrupt Sin3/HDAC complex function, affecting neuronal gene expression and development. | OMIM, ClinVar |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 25.6 | Medium |
| Lymph node | 22.1 | Medium |
| Brain (cortex) | 18.3 | Medium |
| Liver | 15.7 | Medium |
| Heart | 14.2 | Medium |
| Lung | 12.8 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK 293 | 20.5 | Embryonic kidney, high expression |
| HeLa | 18.9 | Cervical carcinoma, moderate expression |
| K562 | 15.3 | Leukemia, moderate expression |
| HepG2 | 14.1 | Hepatocellular carcinoma, moderate expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1A>G (p.Met1?) | Missense | <0.01% | Potential loss of start codon, likely loss of function |
| c.214C>T (p.Arg72Trp) | Missense | <0.01% | May affect protein stability or interaction with Sin3A |
| c.345_346insA | Frameshift | <0.01% | Predicted to cause premature truncation, loss of function |
Mutation functional classification
Loss of Function (LOF)
Frameshift and nonsense mutations that truncate the protein or disrupt the Sin3A-binding domain are predicted to cause loss of function.
Gain of Function (GOF)
No gain-of-function mutations have been reported for SAP18.
Dominant Negative (DN)
Missense mutations that impair complex assembly without complete loss of protein may act in a dominant-negative manner, but evidence is limited.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Sin3/HDAC co-repressor complex pathway
• Chromatin modifying enzymes
• RNA splicing (spliceosome)
Protein Summary
SAP18 is a 153-amino acid protein (18 kDa) that contains a conserved SAP18 domain. It directly interacts with Sin3A and HDAC1/2, forming part of the Sin3/HDAC co-repressor complex. The protein also associates with the spliceosome, linking transcriptional repression to RNA processing. SAP18 is ubiquitously expressed and localizes to the nucleus.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| No Data | ||||
