POLB
GeneName
POLB
Summary
POLB, also known as DNA polymerase beta or Pol II, is a 38 kDa enzyme predominantly expressed in the nucleus and cytoplasm. It plays a critical role in DNA repair processes, particularly in base-excision repair, where it facilitates the removal and replacement of damaged DNA bases. POLB is involved in various biological pathways including DNA damage response, DNA replication, and apoptotic signaling in response to DNA damage. It also participates in lymphocyte development and somatic hypermutation of immunoglobulin genes, highlighting its importance in both cellular maintenance and immune function.
Importance
POLB is relevant to: - DNA repair mechanisms, which are essential for maintaining genomic stability and preventing mutations that can lead to cancer - The study of base-excision repair pathways, providing insights into therapeutic targets for enhancing DNA repair in diseases - Understanding the cellular response to DNA damage, which has implications for cancer therapy and radiobiology - Developmental biology, particularly in processes like in utero embryonic development and lymph node development - Research into neurodegenerative diseases, given its role in neuron apoptotic processes and responses to oxidative stress
Top Products
For researchers investigating POLB, we recommend two excellent primary antibodies. The first is the well-cited polyclonal antibody, Anti-DNA Polymerase beta antibody (ab26343), which has garnered 49 citations, reflecting its reliability in the field. This antibody is particularly effective for Western blotting (WB), immunocytochemistry (ICC), and immunohistochemistry (IHC). Additionally, we offer the recombinant antibody, Anti-DNA Polymerase beta antibody [EPR12722(B)] (ab175197). This monoclonal antibody has been validated for a broader range of applications, including WB, ICC, IHC, and flow cytometry (FC), making it a versatile choice for those requiring consistent performance across different experimental setups. With 9 citations, it is also gaining recognition among researchers. Together, these antibodies provide robust options for studying POLB effectively.
Abcam Product Citation Summary
The data indicates that POLB is being studied in various human contexts, particularly focusing on its interactions and effects in relation to other proteins and compounds. The use of western blotting and immunocytochemistry suggests a detailed investigation into the protein's function and recruitment mechanisms.
Abcam Product Citation Table
Domain
Residues 239-252 form a flexible loop which appears to affect the polymerase fidelity.
Function
Repair polymerase that plays a key role in base-excision repair (PubMed:10556592, PubMed:9207062, PubMed:9572863). During this process, the damaged base is excised by specific DNA glycosylases, the DNA backbone is nicked at the abasic site by an apurinic/apyrimidic (AP) endonuclease, and POLB removes 5'-deoxyribose-phosphate from the preincised AP site acting as a 5'-deoxyribose-phosphate lyase (5'-dRP lyase); through its DNA polymerase activity, it adds one nucleotide to the 3' end of the arising single-nucleotide gap (PubMed:10556592, PubMed:17526740, PubMed:9556598, PubMed:9572863, PubMed:9614142). Conducts 'gap-filling' DNA synthesis in a stepwise distributive fashion rather than in a processive fashion as for other DNA polymerases. It is also able to cleave sugar-phosphate bonds 3' to an intact AP site, acting as an AP lyase (PubMed:9614142).
Post-translational modifications
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.
Sequence Similarities
Belongs to the DNA polymerase type-X family.
Cellular localization
- Nucleus
- Cytoplasm
- Cytoplasmic in normal conditions. Translocates to the nucleus following DNA damage.
Alternative names
DNA polymerase beta, 5'-deoxyribose-phosphate lyase, AP lyase, 5'-dRP lyase, POLB