Serine / threonine-protein kinase tousled-like 2; also known as PKU-alpha; Tousled-like kinase 2 and TLK2; is a nucleus protein which belongs to theprotein kinase superfamily and Ser/Thr protein kinase family. The tousled-like kinases are an evolutionarily conserved family of proteins implicated in DNA repair; DNA replication and mitosis in metazoans and plants. Their absence from the yeasts and other eukaryotic 'microbes' suggests a specific role for them in the development of multicellular organisms. Tousled-like kinase 2 / TLK2 is widely expressed. It is present in fetal placenta; liver; kidney; pancreas; heart and skeletal muscle. It is also found in adult cell lines. Tousled-like kinase 2 / TLK2 contains oneprotein kinase domain. Tousled-like kinase 2 / TLK2 is rapidly and transiently inhibited by phosphorylation following the generation of DNA double-stranded breaks during S-phase. This is cell cycle checkpoint and ATM-pathway dependent and appears to regulate processes involved in chromatin assembly.