POLR1A
RNA Polymerase I Subunit A
Gene Information Card
| Symbol | POLR1A |
|---|---|
| Full Name | RNA Polymerase I Subunit A |
| Gene Type | Protein coding |
| Chromosomal Location | 2p11.2 |
| NCBI Gene ID | 25885 ncbi.nlm.nih.gov/gene/25885 |
| Ensembl ID | ENSG00000115904 |
| UniProt ID | O95602 |
| OMIM ID | 616404 |
| HGNC ID | 17264 |
| Aliases | RPA1, RPA190, A190, POLR1E |
Description
POLR1A encodes the largest catalytic subunit of RNA polymerase I, which synthesizes ribosomal RNA (rRNA) precursors. This subunit contains the active site for RNA synthesis and is essential for ribosome biogenesis. Mutations in POLR1A are associated with Treacher Collins syndrome and have been implicated in various cancers.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Treacher Collins syndrome 4 | Loss-of-function mutations impair rRNA transcription, leading to craniofacial development defects | OMIM #618939 |
| Colorectal cancer | Somatic mutations and copy number alterations may drive tumorigenesis | COSMIC |
| Breast cancer | Overexpression and mutations observed in tumor samples | COSMIC |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 12.5 | Medium |
| Thyroid | 10.2 | Medium |
| Brain | 8.9 | Medium |
| Liver | 7.3 | Low |
| Skeletal muscle | 5.1 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HeLa | 15.3 | High expression |
| HEK293 | 13.8 | High expression |
| A549 | 11.2 | Medium expression |
| MCF7 | 9.6 | Medium expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.3407G>A (p.Arg1136His) | Missense | <0.01% | Unknown; reported in Treacher Collins syndrome |
| c.3701C>T (p.Thr1234Ile) | Missense | <0.01% | Associated with craniofacial defects |
| c.4216C>T (p.Arg1406Cys) | Missense | <0.01% | Likely pathogenic in Treacher Collins syndrome |
Mutation functional classification
Loss of Function (LOF)
Heterozygous loss-of-function mutations reduce rRNA transcription, causing Treacher Collins syndrome.
Gain of Function (GOF)
Not well documented; some somatic mutations in cancer may confer growth advantage.
Dominant Negative (DN)
Possible for missense mutations that disrupt polymerase assembly.
View complete mutation data：
Gene Ontology (GO)
| • DNA-directed 5'-3' RNA polymerase activity | • nucleolus |
| • ribosome biogenesis | • transcription of rDNA |
| • RNA polymerase I complex |
Pathways
• RNA polymerase I transcription
• rRNA processing
• Ribosome biogenesis in eukaryotes
Protein Summary
POLR1A (RPA1) is the 190 kDa catalytic subunit of RNA polymerase I. It contains the active site for RNA synthesis and is localized to the nucleolus. The protein interacts with other Pol I subunits and transcription factors to initiate and elongate rRNA transcripts. Mutations cause Treacher Collins syndrome and are implicated in cancer.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID |
|---|
