Isoform 3 functions as a heterodimer with DNA-repair protein XRCC1 in the nucleus and can correct defective DNA strand-break repair and sister chromatid exchange following treatment with ionizing radiation and alkylating agents. Isoform 1 is targeted to mitochondria, where it functions as a DNA ligase in mitochondrial base-excision DNA repair (, ).
Subcellular locations: Mitochondrion
Contains an N-terminal mitochondrial transit peptide.
Subcellular locations: Mitochondrion
Contains an N-terminal mitochondrial transit peptide.
Subcellular locations: Nucleus
Lacks the N-terminal mitochondrial transit peptide.
Subcellular locations: Nucleus
Lacks the N-terminal mitochondrial transit peptide.
Testis, thymus, prostate and heart.