GTF2H2: General Transcription Factor IIH Subunit 2
A core component of the TFIIH complex involved in transcription initiation and nucleotide excision repair.
Gene Information Card
| Symbol | GTF2H2 |
|---|---|
| Full Name | General Transcription Factor IIH Subunit 2 |
| Gene Type | Protein coding |
| Chromosomal Location | 5q13.2 |
| NCBI Gene ID | 2966 ncbi.nlm.nih.gov/gene/2966 |
| Ensembl ID | ENSG00000145777 |
| UniProt ID | Q13888 |
| OMIM ID | 601748 |
| HGNC ID | 4656 |
| Aliases | BTF2p44, p44, TFIIH, TFB2 |
Description
GTF2H2 encodes the p44 subunit of the general transcription factor IIH (TFIIH) complex. TFIIH is essential for RNA polymerase II transcription initiation and nucleotide excision repair (NER). The p44 subunit interacts with the XPD helicase and is critical for complex stability and ATP-dependent helicase activity.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Xeroderma Pigmentosum (XP) | Defective NER due to impaired TFIIH function; mutations in GTF2H2 can disrupt XPD interaction, reducing DNA repair capacity. | ClinVar, OMIM |
| Trichothiodystrophy (TTD) | Mutations affecting TFIIH stability lead to transcription and repair defects, causing brittle hair and developmental abnormalities. | OMIM, PubMed |
| Cockayne Syndrome (CS) | Impaired transcription-coupled repair; GTF2H2 mutations may contribute to photosensitivity and neurological symptoms. | OMIM, PubMed |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 15.2 | Medium |
| Lymph node | 12.8 | Medium |
| Brain | 10.5 | Medium |
| Liver | 8.3 | Low |
| Heart | 7.1 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HeLa | 14.5 | Cervical cancer cell line |
| HEK293 | 13.2 | Embryonic kidney cells |
| K562 | 11.9 | Leukemia cell line |
| A549 | 10.8 | Lung carcinoma cells |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1A>G (p.Met1?) | Missense | <0.01% | Loss of start codon; likely loss of function |
| c.457C>T (p.Arg153Trp) | Missense | <0.01% | Impaired XPD binding; reduced NER activity |
| c.832G>A (p.Glu278Lys) | Missense | <0.01% | Altered TFIIH stability; associated with TTD |
Mutation functional classification
Loss of Function (LOF)
Mutations that disrupt p44-XPD interaction or destabilize TFIIH lead to reduced transcription and NER, causing XP or TTD.
Gain of Function (GOF)
Not reported for GTF2H2.
Dominant Negative (DN)
Some missense mutations may produce a defective p44 that poisons TFIIH complex function, though evidence is limited.
View complete mutation data：
Gene Ontology (GO)
| • DNA repair (GO:0006281) | • transcription initiation from RNA polymerase II promoter (GO:0006367) |
| • helicase activity (GO:0004386) | • protein binding (GO:0005515) |
| • nucleoplasm (GO:0005654) |
Pathways
• Nucleotide Excision Repair (hsa03420)
• RNA Polymerase II Transcription Initiation (hsa03022)
• TFIIH Complex (R-HSA-5696398)
Protein Summary
The p44 protein (UniProt Q13888) is a 44 kDa subunit of TFIIH. It contains a zinc finger domain and a C-terminal domain that binds XPD. p44 stimulates the ATPase and helicase activities of XPD, essential for promoter opening during transcription and DNA unwinding during NER. It also interacts with other TFIIH subunits (XPB, p62, p34) to maintain complex integrity.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| GTF2H2C_2 Knockout HEK293 Cell Line | EDJ-KQ13697 | Human | 730394 | Details Get a Quote |
| GTF2H2C_2 Knockout A-549 Cell Line | EDJ-KQ43405 | Human | 730394 | Details Get a Quote |
| GTF2H2C_2 Knockout HCT 116 Cell Line | EDJ-KQ43406 | Human | 730394 | Details Get a Quote |
| GTF2H2C_2 Knockout HeLa Cell Line | EDJ-KQ43407 | Human | 730394 | Details Get a Quote |
| GTF2H2 Knockout HEK293 Cell Line | EDJ-KQ50322 | Human | 2966 | Details Get a Quote |
| GTF2H2 Knockout HeLa Cell Line | EDJ-KQ53455 | Human | 2966 | Details Get a Quote |
| GTF2H2 Knockout A-549 Cell Line | EDJ-KQ61928 | Human | 2966 | Details Get a Quote |
| GTF2H2 Knockout HCT 116 Cell Line | EDJ-KQ70409 | Human | 2966 | Details Get a Quote |
