ASF1A: Anti-Silencing Function 1A Histone Chaperone
A key histone chaperone regulating chromatin assembly, DNA repair, and transcriptional memory.
Gene Information Card
| Symbol | ASF1A |
|---|---|
| Full Name | Anti-silencing function 1A histone chaperone |
| Gene Type | Protein coding |
| Chromosomal Location | 6q22.31 |
| NCBI Gene ID | 25842 ncbi.nlm.nih.gov/gene/25842 |
| Ensembl ID | ENSG00000111875 |
| UniProt ID | Q9Y294 |
| OMIM ID | 609189 |
| HGNC ID | 20995 |
| Aliases | CIA, CGI-98, hASF1A, HSPC146 |
Description
ASF1A encodes a conserved histone chaperone that facilitates the deposition of histones H3/H4 onto DNA during replication, transcription, and repair. It interacts with the HAT1 complex and the CAF-1 complex to regulate chromatin assembly and disassembly. ASF1A also plays a role in transcriptional silencing, DNA damage checkpoint activation, and cellular senescence.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Cancer (multiple types) | ASF1A overexpression or mutation disrupts chromatin assembly, promoting genomic instability and tumor progression. | COSMIC; PMID: 21502514 |
| Aging-related disorders | ASF1A depletion accelerates cellular senescence via p53 pathway activation. | PMID: 21502514 |
| DNA repair deficiencies | Loss of ASF1A impairs homologous recombination repair by reducing histone deposition at double-strand breaks. | PMID: 20551164 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 12.5 | Medium |
| Bone marrow | 10.2 | Medium |
| Lymph node | 9.8 | Medium |
| Brain | 7.1 | Low |
| Liver | 5.3 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK293 | 14.0 | High expression |
| HeLa | 11.5 | Medium expression |
| K562 | 9.2 | Medium expression |
| HepG2 | 6.8 | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.287A>G (p.Asn96Ser) | Missense | <0.1% | Alters histone-binding affinity; potential loss of function |
| c.412C>T (p.Arg138Trp) | Missense | <0.1% | Reduced interaction with H3-H4; impaired chaperone activity |
| c.1A>G (p.Met1Val) | Start loss | Rare | Likely loss of protein expression |
Mutation functional classification
Loss of Function (LOF)
Mutations that disrupt histone-binding or reduce protein stability lead to impaired chromatin assembly and DNA repair.
Gain of Function (GOF)
Not well documented; overexpression in cancers may confer proliferative advantage.
Dominant Negative (DN)
Mutant ASF1A that binds histones but fails to release them could block normal chaperone function.
View complete mutation data：
Gene Ontology (GO)
| • chromatin assembly | • nucleosome assembly |
| • DNA repair | • regulation of transcription |
| • histone exchange | • protein heterodimerization activity |
| • histone binding |
Pathways
• Chromatin organization
• DNA double-strand break repair
• Telomere maintenance
• Senescence and autophagy
Protein Summary
ASF1A is a 204-amino-acid histone chaperone that binds histones H3 and H4, shuttling them to chromatin assembly factors. It is essential for replication-coupled nucleosome assembly and participates in transcription elongation, DNA repair, and epigenetic silencing. The protein contains a conserved B-domain that mediates interaction with H3-H4 dimers. ASF1A is ubiquitously expressed with highest levels in testis and lymphoid tissues.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| ASF1A Knockout HEK293 Cell Line | EDJ-KQ8258 | Human | 25842 | Details Get a Quote |
| ASF1A Knockout A-549 Cell Line | EDJ-KQ34193 | Human | 25842 | Details Get a Quote |
| ASF1A Knockout HCT 116 Cell Line | EDJ-KQ34194 | Human | 25842 | Details Get a Quote |
| ASF1A Knockout HeLa Cell Line | EDJ-KQ34195 | Human | 25842 | Details Get a Quote |
