Anti-DNA Ligase III/LIG3 antibody

Supplementary info

Activity summary

DNA Ligase III also known as LIG3 or Lig 3 is an enzyme that plays a central role in DNA repair by catalyzing the joining of DNA strands. Mechanically it facilitates the ligation step in the DNA repair process sealing nicks in the DNA backbone. This ligase has a sizing mass of approximately 103 kDa. It is expressed widely in human cells with a high concentration in tissues with active DNA repair needs such as testes and ovaries. Ligase acts in various subcellular locations including the nucleus and mitochondria with distinct isoforms functioning in these compartments.

Biological function summary

DNA Ligase III is significant in maintaining genomic stability. It often operates as part of multi-protein complexes interacting especially with XRCC1 during base excision repair (BER). It ensures the continuity of DNA strands after damage-induced breaks are processed. LIG3 also has a pivotal function in the mitochondria where it is involved in repair and replication of mitochondrial DNA therefore preserving mitochondrial genome integrity.

Pathways

DNA Ligase III is an integral part of the DNA repair pathways particularly the base excision repair (BER) and single-strand break repair (SSBR) pathways. In the BER pathway LIG3 collaborates closely with other proteins like XRCC1 to mend damaged DNA by filling in missing nucleotides and sealing nicks. It also plays a role in non-homologous end joining (NHEJ) though this is more dominantly accomplished by DNA Ligase IV. These pathways are important for correcting oxidative damage and abasic sites that can disrupt the DNA structure.

Associated diseases and disorders

DNA Ligase III has associations with certain syndromes and cancers. Mutations or malfunctions in this enzyme can lead to ataxia-telangiectasia-like disorder owing to impaired DNA repair processes. Additionally LIG3 expression is often evaluated in the context of cancerous cells where aberrant repair processes could promote tumor progression. A connection with XRCC1 another key player in the repair machinery is critical as XRCC1 mutations may magnify the impact of LIG3 deficiencies contributing to disease pathology.