Cloning of mouse mitochondrial thymidine kinase 2 cDNA

Phosphorylation of anti-viral nucleoside analogs by mitochondrial thymidine kinase 2 (TK2) has been implicated as a mechanism for the mitochondrial to xicity caused hy several of these compounds. We have cloned the cDNA of mou se TK2 and shown that the enzyme is targeted to the mitochondria when expre ssed in fusion with the green fluorescent protein. This is the first report on the cloning of a mitochondrial TK2 and will contribute to elucidate the role of TK2 in the pharmacological activation of nucleoside analogs, (C) 1 999 Federation of European Biochemical Societies.