Abstract
Autoantigen Ku is a DNA-binding protein complex composed of -80 kDa and -70kDa subunits. Although the role Ku complex plays in the cell nucleus remains unelucidated, an increasing number of studies have demonstrated that the Ku complex plays widespread functional roles in the cell, of which DNA repair and recombination, DNA replication, and transcription are proposed. Recent findings of proteins with sequence similarity to the human Ku complex and the association of Ku complex with DNAdependent protein kinase lead us to speculation on its role as a transcriptional regulator. Moreover, successful development of a monoclonal antibody cross-reactive to the Ku p70 subunit homologous to a wide variety of species has opened a novel functional role of the Ku complex in the establishment of nuclear structure.
