POLB

POLB is a DNA polymerase involved in base excision and repair, also called gap-filling DNA synthesis. The encoded protein, acting as a monomer, is normally found in the cytoplasm, but it translocates to the nucleus upon DNA damage.

Full Name

DNA Polymerase Beta

Function

Repair polymerase that plays a key role in base-excision repair. Has 5'-deoxyribose-5-phosphate lyase (dRP lyase) activity that removes the 5' sugar phosphate and also acts as a DNA polymerase that adds one nucleotide to the 3' end of the arising single-nucleotide gap. Conducts 'gap-filling' DNA synthesis in a stepwise distributive fashion rather than in a processive fashion as for other DNA polymerases.

Biological Process

AgingIEA:Ensembl
Base-excision repairManual Assertion Based On ExperimentIDA:UniProtKB
Base-excision repair, gap-fillingTAS:Reactome
Cellular response to DNA damage stimulusManual Assertion Based On ExperimentIMP:UniProtKB
DNA repairManual Assertion Based On ExperimentTAS:ProtInc
DNA-templated DNA replicationManual Assertion Based On ExperimentTAS:ProtInc
Double-strand break repair via nonhomologous end joiningManual Assertion Based On ExperimentIBA:GO_Central
Homeostasis of number of cellsIEA:Ensembl
Immunoglobulin heavy chain V-D-J recombinationIEA:Ensembl
In utero embryonic developmentIEA:Ensembl
Inflammatory responseIEA:Ensembl
Intrinsic apoptotic signaling pathway in response to DNA damageIEA:Ensembl
Lymph node developmentIEA:Ensembl
Neuron apoptotic processIEA:Ensembl
Pyrimidine dimer repairIEA:Ensembl
Response to ethanolIEA:Ensembl
Response to gamma radiationIEA:Ensembl
Response to hyperoxiaIEA:Ensembl
Salivary gland morphogenesisIEA:Ensembl
Somatic hypermutation of immunoglobulin genesIEA:Ensembl
Spleen developmentIEA:Ensembl

Cellular Location

Nucleus
Cytoplasm
Cytoplasmic in normal conditions. Translocates to the nucleus following DNA damage.

PTM

Methylation by PRMT6 stimulates the polymerase activity by enhancing DNA binding and processivity.
Ubiquitinated at Lys-41, Lys-61 and Lys-81: monoubiquitinated by HUWE1/ARF-BP1. Monoubiquitinated protein is then the target of STUB1/CHIP, which catalyzes polyubiquitination from monoubiquitin, leading to degradation by the proteasome. USP47 mediates the deubiquitination of monoubiquitinated protein, preventing polyubiquitination by STUB1/CHIP and its subsequent degradation.