TAF9B RNA Polymerase II, TATA Box Binding Protein (TBP)-Associated Factor
A component of the TFIID and SAGA complexes involved in transcription initiation and chromatin remodeling.
Gene Information Card
| Symbol | TAF9B |
|---|---|
| Full Name | TATA-box binding protein associated factor 9b |
| Gene Type | protein-coding |
| Chromosomal Location | Xq21.1 |
| NCBI Gene ID | 51616 ncbi.nlm.nih.gov/gene/51616 |
| Ensembl ID | ENSG00000187325 |
| UniProt ID | Q9HBM1 |
| OMIM ID | 300791 |
| HGNC ID | 11547 |
| Aliases | TAF9L, TAFII31L, MGC:3196 |
Description
TAF9B encodes a subunit of the transcription factor IID (TFIID) and SAGA (Spt-Ada-Gcn5-acetyltransferase) complexes. These complexes are essential for RNA polymerase II-mediated transcription initiation and chromatin modification. TAF9B specifically interacts with TBP and other TAFs to facilitate promoter recognition and transcriptional activation. It is highly similar to TAF9 but is encoded on the X chromosome.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Intellectual disability, X-linked | Disruption of TFIID complex function affecting neuronal gene expression | OMIM #300791; rare variants reported in affected males |
| Cancer (various) | Altered expression or mutation may impact cell cycle and proliferation genes | COSMIC database; somatic mutations in multiple tumor types |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 12.3 | Medium |
| Brain (cerebellum) | 8.1 | Medium |
| Heart | 6.5 | Low |
| Liver | 4.2 | Low |
| Lung | 5.0 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK293 | 10.5 | Embryonic kidney; moderate expression |
| HeLa | 7.8 | Cervical carcinoma; moderate expression |
| K562 | 6.1 | Leukemia; low 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% | Likely loss of start codon; predicted loss of function |
| c.287C>T (p.Pro96Leu) | missense | <0.01% | Unknown significance; reported in ClinVar |
Mutation functional classification
Loss of Function (LOF)
Missense or nonsense variants that disrupt TAF9B interaction with TBP or other TAFs, impairing transcription initiation.
Gain of Function (GOF)
Not well characterized; no known gain-of-function mutations reported.
Dominant Negative (DN)
Theoretical; mutations in conserved domains may interfere with TFIID complex assembly.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Transcription initiation by RNA polymerase II (Reactome: R-HSA-75953)
• Chromatin modifying enzymes (Reactome: R-HSA-3247509)
Protein Summary
TAF9B is a 264-amino acid protein (UniProt Q9HBM1) that contains a conserved histone-fold domain (HFD) characteristic of TAF subunits. It forms heterodimers with TAF6 and TAF12 within the TFIID complex, contributing to DNA binding and promoter recognition. TAF9B also participates in the SAGA complex, linking transcription activation with histone acetylation. Its expression is ubiquitous but enriched in testis and brain.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| TAF9B Knockout HEK293 Cell Line | EDJ-KQ11158 | Human | 51616 | Details Get a Quote |
| TAF9B Knockout A-549 Cell Line | EDJ-KQ39169 | Human | 51616 | Details Get a Quote |
| TAF9B Knockout HeLa Cell Line | EDJ-KQ39170 | Human | 51616 | Details Get a Quote |
| TAF9B Knockout HCT 116 Cell Line | EDJ-KQ37854 | Human | 51616 | Details Get a Quote |
