POLH
Gene Information
- Official Symbol: POLH
- Official Name: DNA polymerase eta
- Aliases and Previous Symbols: N/A
- Entrez ID: 5429
- UniProt: Q9Y253
- Interactions: BioGRID
- PubMed articles: Open PubMed
- OMIM: Open OMIM
Function Summary
- Entrez Summary: This gene encodes a member of the Y family of specialized DNA polymerases. It copies undamaged DNA with a lower fidelity than other DNA-directed polymerases. However, it accurately replicates UV-damaged DNA; when thymine dimers are present, this polymerase inserts the complementary nucleotides in the newly synthesized DNA, thereby bypassing the lesion and suppressing the mutagenic effect of UV-induced DNA damage. This polymerase is thought to be involved in hypermutation during immunoglobulin class switch recombination. Mutations in this gene result in XPV, a variant type of xeroderma pigmentosum. Several transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, May 2014].
- UniProt Summary: DNA polymerase specifically involved in the DNA repair by translesion synthesis (TLS) (PubMed:10385124, PubMed:11743006, PubMed:24449906). Due to low processivity on both damaged and normal DNA, cooperates with the heterotetrameric (REV3L, REV7, POLD2 and POLD3) POLZ complex for complete bypass of DNA lesions. Inserts one or 2 nucleotide(s) opposite the lesion, the primer is further extended by the tetrameric POLZ complex. In the case of 1,2-intrastrand d(GpG)-cisplatin cross-link, inserts dCTP opposite the 3' guanine (PubMed:24449906). Particularly important for the repair of UV-induced pyrimidine dimers (PubMed:10385124, PubMed:11743006). Although inserts the correct base, may cause base transitions and transversions depending upon the context. May play a role in hypermutation at immunoglobulin genes (PubMed:11376341, PubMed:14734526). Forms a Schiff base with 5'- deoxyribose phosphate at abasic sites, but does not have any lyase activity, preventing the release of the 5'-deoxyribose phosphate (5'-dRP) residue. This covalent trapping of the enzyme by the 5'- dRP residue inhibits its DNA synthetic activity during base excision repair, thereby avoiding high incidence of mutagenesis (PubMed:14630940). Targets POLI to replication foci (PubMed:12606586). {ECO:0000269|PubMed:10385124, ECO:0000269|PubMed:11376341, ECO:0000269|PubMed:11743006, ECO:0000269|PubMed:12606586, ECO:0000269|PubMed:14630940, ECO:0000269|PubMed:14734526, ECO:0000269|PubMed:24449906}.
CRISPR Data
Essentiality in NALM6
- Essentiality Rank: 4196
- Expression level (log2 read counts): 5.95
POLH Expression in NALM6 Cells: 5.95
