Holliday Junction Recognition Protein (HJURP)

The deduced 748-amino acid protein has an N-terminal coiled-coil domain and 3 putative ATM-binding S/TQ motifs. Northern blot analysis detected a 2.7-kb transcript that was expressed highly in testis and more weakly in thymus and bone marrow. Western blot analysis detected HJURP at an apparent molecular mass of 83 kD, which was reduced following phosphatase treatment. In synchronized human osteosarcoma cells, HJURP localized to the nucleus and was associated with different subnuclear structures at various phases of the cell cycle.HJURP coimmunoprecipitated with the Holliday junction protein MSH5 and with NBS1, a component of a protein complex involved in DNA double-strand break repair. HJURP expression was increased by genotoxic stress, but not in ATM-deficient cells.