POLI (DNA Polymerase Iota)
A specialized DNA polymerase involved in translesion synthesis and somatic hypermutation
Gene Information Card
| Symbol | POLI |
|---|---|
| Full Name | DNA Polymerase Iota |
| Gene Type | Protein coding |
| Chromosomal Location | 18q21.2 |
| NCBI Gene ID | 11201 ncbi.nlm.nih.gov/gene/11201 |
| Ensembl ID | ENSG00000101751 |
| UniProt ID | Q9UNA4 |
| OMIM ID | 604429 |
| HGNC ID | 9184 |
| Aliases | RAD30B, eta2, iota |
Description
POLI encodes DNA polymerase iota (Pol ι), a member of the Y-family of DNA polymerases. Pol ι is specialized in translesion synthesis (TLS), allowing replication past damaged DNA templates, and participates in somatic hypermutation of immunoglobulin genes. It exhibits low fidelity on undamaged DNA and has a unique preference for incorporating dGTP opposite template bases.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Cancer (various types) | Altered POLI expression and mutations may contribute to genomic instability and tumorigenesis via defective TLS. | NCBI Gene, COSMIC |
| Xeroderma Pigmentosum Variant (XPV) | POLI mutations are not causative; however, POLI is a paralog of POLH (XPV gene) and may modulate disease severity. | OMIM, NCBI Gene |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 12.8 | Medium |
| Lymph node | 8.2 | Low |
| Spleen | 7.5 | Low |
| Bone marrow | 6.9 | Low |
| Skin | 5.3 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HeLa | 10.5 | Cervical cancer cell line |
| K562 | 8.1 | Leukemia cell line |
| A549 | 6.7 | Lung cancer cell line |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1234C>T (p.Arg412Cys) | Missense | <0.1% | Unknown functional impact |
| c.1567G>A (p.Gly523Arg) | Missense | <0.1% | Reported in COSMIC; potential loss of function |
Mutation functional classification
Loss of Function (LOF)
Mutations that impair catalytic activity or TLS ability may increase genomic instability.
Gain of Function (GOF)
Not well documented; gain-of-function variants could increase mutagenesis.
Dominant Negative (DN)
Not reported for POLI.
View complete mutation data：
Gene Ontology (GO)
| • DNA-directed DNA polymerase activity | • damaged DNA binding |
| • nucleotide-excision repair | • translesion synthesis |
| • somatic hypermutation of immunoglobulin genes |
Pathways
• Translesion synthesis (Y-family polymerases)
• Somatic hypermutation of immunoglobulin genes
Protein Summary
DNA polymerase iota is a 715-amino acid protein with a catalytic polymerase domain and a C-terminal PCNA-binding motif. It is highly error-prone on undamaged templates but can bypass certain lesions, such as 8-oxoguanine and UV-induced photoproducts, in a relatively accurate manner. Pol ι interacts with PCNA and other TLS components to facilitate replication fork progression.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| POLI Knockout HEK293 Cell Line | EDJ-KQ7331 | Human | 11201 | Details Get a Quote |
| POLI Knockout HeLa Cell Line | EDJ-KQ31045 | Human | 11201 | Details Get a Quote |
| POLI Knockout A-549 Cell Line | EDJ-KQ32415 | Human | 11201 | Details Get a Quote |
| POLI Knockout HCT 116 Cell Line | EDJ-KQ32416 | Human | 11201 | Details Get a Quote |
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