This gene encodes a nuclear serine/threonine kinase that was first identified in Arabidopsis. The encoded protein is thought to function in the regulation of chromatin assembly in the S phase of the cell cycle by regulating the levels of a histone H3/H4 chaperone. This protein is associated with double-strand break repair of DNA damage caused by radiation. Pseudogenes of this gene are present on chromosomes 10 and 17. Alternate splicing results in multiple transcript variants. [From RefSeq]