lupus Ku autoimmune antigen, ATP-dependent DNA helicase-2, CTC box binding factor (CTCBF) or thyroid-lupus autoantigen (TLAA)

Function: - Ku is a regulatory component of the DNA-associated kinase that phosphorylates RNA polymerase 2 & transcription factor SP1 - targets DNA-dependent protein kinase to DNA termini or other discontinuities in DNA structure - Ku also activates transcription from U1 small nuclear RNA & the human transferrin receptor gene - by virtue of its homology with rat Enhancer 1 binding factor, Ku may also be essential for RNA polymerase 1-directed transcription Structurre: - heterodimer of XRCC5/XRCC6 Pathology: - autoantibodies to Ku protein are found in patients with a) systemic lupus erythematosus (SLE) b) scleroderma/polymyositis overlap syndrome c) other rheumatic diseases

Related

anti-Ku antibody Ku antibody in body fluid

General

DNA-binding protein helicase (DNA unwinding protein, DNA untwisting protein) molecular complex transcription factor (TF)

Properties

COMPARTMENT: cell nucleus MOTIF: DNA-binding motif active site MOTIF: P-loop FOR-BINDING-OF: adenosine triphosphate SUBUNITS: X-ray repair cross-complementing protein 6 MOTIF: serine-rich region {2-61} MOTIF: serine residue (SEVERAL) acetylation site SITE: N-TERMINUS EFFECTOR-BOUND: acetyl Ser phosphorylation site {S6} acidic region {11-29} MOTIF: acidic residue (SEVERAL) Ser phosphorylation site {S27} lysine residue {K31} Ser phosphorylation site {S51} Ser phosphorylation site {S222} Ku {261-468} MOTIF: acidic region {330-342} MOTIF: acidic residue (SEVERAL) Thr phosphorylation site {T455} Ser phosphorylation site {S520} SAP {573-607} X-ray repair cross-complementing protein 5 MOTIF: leucine zipper SITE: 138-165 FOR-BINDING-VIA: leucine zipper Ku {251-460} MOTIF: Ser phosphorylation site {S258} proline-rich region SITE: 478-519 MOTIF: proline residue (SEVERAL) Ser phosphorylation site {S577} Ser phosphorylation site {S579} Ser phosphorylation site {S580} Thr phosphorylation site {T715} EEXXXDL {720-728}

References

- Hoff CM, Ghosh AK, Prabhakar BS, Jacob ST. Enhancer 1 binding factor, a Ku-related protein, is a positive regulator of RNA polymerase I transcription initiation. Proc Natl Acad Sci U S A. 1994 Jan 18;91(2):762-6. PMID: 8290597

Components

X-ray repair cross-complementing protein 5; 86 kD subunit of Ku antigen; p86Ku; ATP-dependent DNA helicase 2 subunit 2; ATP-dependent DNA helicase II 80 kD subunit; CTC box-binding factor 85 kD subunit; CTC85; CTCBF; DNA repair protein XRCC5; Ku80; Ku86; Lupus Ku autoantigen protein p86; nuclear factor IV; thyroid-lupus autoantigen; TLAA; X-ray repair complementing defective repair in chinese hamster cells 5 (double-strand-break rejoining) (XRCC5, G22P2) X-ray repair cross-complementing protein 6; 5'-deoxyribose-5-phosphate lyase Ku70; 5'-dRP lyase Ku70; 70 kD subunit of Ku antigen; ATP-dependent DNA helicase 2 subunit 1; ATP-dependent DNA helicase II 70 kD subunit; CTC box-binding factor 75 kD subunit; CTC75; CTCBF; DNA repair protein XRCC6; Lupus Ku autoantigen protein p70; Ku70; thyroid-lupus autoantigen; TLAA; X-ray repair complementing defective repair in chinese hamster cells 6 (XRCC6, G22P1)