Ku70 Single-stranded DNA-dependent ATP-dependent helicase. Has a role in chromosome translocation. The DNA helicase II complex binds preferentially to fork-like ends of double-stranded DNA in a cell cycle-dependent manner. It works in the 3'-5' direction. Binding to DNA may be mediated by XRCC6. Involved in DNA non-homologous end joining (NHEJ) required for double-strand break repair and V(D)J recombination. The XRCC5/6 dimer acts as regulatory subunit of the DNA-dependent protein kinase complex DNA-PK by increasing the affinity of the catalytic subunit PRKDC to DNA by 100-fold. The XRCC5/6 dimer is probably involved in stabilizing broken DNA ends and bringing them together. The assembly of the DNA-PK complex to DNA ends is required for the NHEJ ligation step. Required for osteocalcin gene expression. Probably also acts as a 5'-deoxyribose-5-phosphate lyase (5'-dRP lyase), by catalyzing the beta-elimination of the 5' deoxyribose-5-phosphate at an abasic site near double-strand breaks. 5'-dRP lyase activity allows to 'clean' the termini of abasic sites, a class of nucleotide damage commonly associated with strand breaks, before such broken ends can be joined. The XRCC5/6 dimer together with APEX1 acts as a negative regulator of transcription. Plays a role in the regulation of DNA virus-mediated innate immune response by assembling into the HDP-RNP complex, a complex that serves as a platform for IRF3 phosphorylation and subsequent innate immune response activation through the cGAS-STING pathway. Belongs to the ku70 family. 2 alternatively spliced human isoforms have been reported. Note: This description may include information from UniProtKB.

Protein type: DNA repair, damage; DNA-binding; EC 3.6.4.-; EC 4.2.99.-; Helicase; Nuclear receptor co-regulator; RNA-binding

Chromosomal Location of human Ortholog: 22q13.2

Cellular Component: cytosol; DNA-dependent protein kinase complex; extracellular region; ficolin-1-rich granule lumen; Ku70:Ku80 complex; nonhomologous end joining complex; nuclear telomere cap complex; nucleolus; nucleoplasm; nucleus; protein-containing complex; protein-DNA complex; secretory granule lumen; transcription regulator complex

Molecular Function: 5'-deoxyribose-5-phosphate lyase activity; ATP binding; ATP hydrolysis activity; ATP-dependent activity, acting on DNA; cyclin binding; damaged DNA binding; DNA binding; DNA end binding; DNA helicase activity; double-stranded DNA binding; double-stranded telomeric DNA binding; protein binding; protein-containing complex binding; scaffold protein binding; telomeric DNA binding; transcription cis-regulatory region binding

Biological Process: activation of innate immune response; cellular hyperosmotic salinity response; cellular response to gamma radiation; cellular response to X-ray; DNA duplex unwinding; DNA ligation; double-strand break repair via classical nonhomologous end joining; double-strand break repair via nonhomologous end joining; innate immune response; negative regulation of DNA-templated transcription; positive regulation of DNA-templated transcription; positive regulation of lymphocyte differentiation; positive regulation of protein kinase activity; positive regulation of transcription by RNA polymerase II; recombinational repair; regulation of smooth muscle cell proliferation; telomere maintenance

Reference #: P12956 (UniProtKB)

Alt. Names/Synonyms: 5'-deoxyribose-5-phosphate lyase Ku70; 5'-dRP lyase Ku70; 70 kDa subunit of Ku antigen; ATP-dependent DNA helicase 2 subunit 1; ATP-dependent DNA helicase II 70 kDa subunit; ATP-dependent DNA helicase II, 70 kDa subunit; CTC box binding factor 75 kDa subunit; CTC box-binding factor 75 kDa subunit; CTC75; CTCBF; DNA repair protein XRCC6; G22P1; Ku autoantigen p70 subunit; Ku autoantigen, 70kDa; Ku70; Lupus Ku autoantigen protein p70; ML8; thyroid autoantigen 70kD (Ku antigen); thyroid autoantigen 70kDa (Ku antigen); Thyroid-lupus autoantigen; thyroid-lupus autoantigen p70; TLAA; X-ray repair complementing defective repair in Chinese hamster cells 6; X-ray repair cross complementing 6; X-ray repair cross-complementing protein 6; XRCC6

Gene Symbols: XRCC6

Molecular weight: 69,843 Da

Basal Isoelectric point: 6.23 Predict pI for various phosphorylation states

Protein-Specific Antibodies, siRNAs or Recombinant Proteins from Cell Signaling Technology^®

Select Structure to View Below
Ku70

Get PyMOL Script Get Chimera Script