POLI

POLI is an error-prone DNA polymerase involved in DNA repair. The encoded protein promotes DNA synthesis across lesions in the template DNA, which other polymerases cannot do. The encoded polymerase inserts deoxynucleotides across lesions and then relies on DNA polymerase zeta to extend the nascent DNA strand to bypass the lesion.

Full Name

DNA Polymerase Iota

Function

Error-prone DNA polymerase specifically involved in DNA repair (PubMed:11013228, PubMed:11387224).
Plays an important role in translesion synthesis, where the normal high-fidelity DNA polymerases cannot proceed and DNA synthesis stalls (PubMed:11013228, PubMed:11387224, PubMed:14630940, PubMed:15199127).
Favors Hoogsteen base-pairing in the active site (PubMed:15254543).
Inserts the correct base with high-fidelity opposite an adenosine template (PubMed:15254543).
Exhibits low fidelity and efficiency opposite a thymidine template, where it will preferentially insert guanosine (PubMed:11013228).
May play a role in hypermutation of immunoglobulin genes (PubMed:12410315).
Forms a Schiff base with 5'-deoxyribose phosphate at abasic sites, but may not have lyase activity (PubMed:11251121, PubMed:14630940).

Biological Process

DNA repairManual Assertion Based On ExperimentTAS:ProtInc
DNA replicationIEA:UniProtKB-KW
Error-prone translesion synthesisTAS:Reactome
Translesion synthesisManual Assertion Based On ExperimentIBA:GO_Central

Cellular Location

Nucleus
Binding to ubiquitin mediates localization to replication forks after UV-induced DNA damage.

PTM

Monoubiquitinated. Protein monoubiquitination prevents POLI binding to ubiquitin via the ubiquitin-binding motif 1 and ubiquitin-binding motif 2.