ASF1B: Anti-Silencing Function 1B Histone Chaperone
A histone chaperone involved in chromatin assembly, DNA replication, and repair, with implications in cancer and cell proliferation.
Gene Information Card
| Symbol | ASF1B |
|---|---|
| Full Name | Anti-Silencing Function 1B Histone Chaperone |
| Gene Type | Protein coding |
| Chromosomal Location | 19p13.12 |
| NCBI Gene ID | 55723 ncbi.nlm.nih.gov/gene/55723 |
| Ensembl ID | ENSG00000105647 |
| UniProt ID | Q9NVP2 |
| OMIM ID | 609190 |
| HGNC ID | 20996 |
| Aliases | ASF1B, CIA-II, hAsf1b, FLJ10604 |
Description
ASF1B (Anti-Silencing Function 1B Histone Chaperone) is a protein-coding gene that encodes a member of the ASF1 family of histone chaperones. It plays a critical role in chromatin assembly, DNA replication, and DNA repair by facilitating the deposition of histones H3/H4 onto newly synthesized DNA. ASF1B is highly expressed in proliferating cells and is implicated in cell cycle progression and cancer development.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Breast cancer | Overexpression of ASF1B promotes cell proliferation and tumor growth; associated with poor prognosis. | PMID: 25944712; COSMIC |
| Lung cancer | Upregulation of ASF1B correlates with increased proliferation and metastasis. | PMID: 29367642; COSMIC |
| Hepatocellular carcinoma | ASF1B overexpression linked to enhanced cell cycle progression and poor survival. | PMID: 30606238; COSMIC |
| Colorectal cancer | ASF1B amplification and overexpression drive tumorigenesis via chromatin remodeling. | PMID: 27562874; COSMIC |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 15.2 | High |
| Bone marrow | 12.8 | High |
| Lymph node | 10.5 | Medium |
| Spleen | 9.3 | Medium |
| Thymus | 8.7 | Medium |
| Brain | 1.2 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HeLa | 18.5 | Cervical cancer cell line; high expression |
| A549 | 14.2 | Lung cancer cell line; high expression |
| MCF7 | 12.1 | Breast cancer cell line; high expression |
| HEK293 | 8.3 | Embryonic kidney; moderate expression |
| K562 | 6.7 | Leukemia cell line; moderate expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1A>G (p.Met1?) | Missense | <0.1% | Loss of start codon; likely loss of function |
| c.214C>T (p.Arg72Trp) | Missense | <0.1% | Unknown significance; reported in COSMIC |
| c.487G>A (p.Glu163Lys) | Missense | <0.1% | Unknown significance; reported in COSMIC |
| c.632_633insA | Frameshift | <0.1% | Predicted loss of function |
Mutation functional classification
Loss of Function (LOF)
Frameshift and nonsense mutations predicted to truncate the protein, impairing histone chaperone activity.
Gain of Function (GOF)
Not well characterized; overexpression in tumors suggests potential gain-of-function via increased proliferation.
Dominant Negative (DN)
Not reported for ASF1B.
View complete mutation data：
Gene Ontology (GO)
Pathways
• REACT: R-HSA-73762 - RNA Polymerase I Transcription
• REACT: R-HSA-73886 - Chromosome Maintenance
• REACT: R-HSA-2559585 - DNA Replication
• REACT: R-HSA-5696398 - DNA Repair
Protein Summary
ASF1B is a 204-amino acid histone chaperone that binds histones H3 and H4, facilitating their deposition onto DNA during replication and repair. It interacts with the CAF-1 complex and is essential for S-phase progression. The protein is highly conserved and expressed in proliferative tissues. Its overexpression in multiple cancers suggests a role in oncogenesis.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| ASF1B Knockout HEK293 Cell Line | EDJ-KQ12456 | Human | 55723 | Details Get a Quote |
| ASF1B Knockout A-549 Cell Line | EDJ-KQ41392 | Human | 55723 | Details Get a Quote |
| ASF1B Knockout HCT 116 Cell Line | EDJ-KQ41393 | Human | 55723 | Details Get a Quote |
| ASF1B Knockout HeLa Cell Line | EDJ-KQ41394 | Human | 55723 | Details Get a Quote |
