title: Adenylate kinase 1 knockout mice have normal thiamine triphosphate levels.
abstract: Thiamine triphosphate (ThTP) is found at low concentrations in most animal tissues and it may act as a phosphate donor for the phosphorylation of proteins, suggesting a potential role in cell signaling. Two mechanisms have been proposed for the enzymatic synthesis of ThTP. A thiamine diphosphate (ThDP) kinase (ThDP+ATP if ThTP+ADP) has been purified from brewer's yeast and shown to exist in rat liver. However, other data suggest that, at least in skeletal muscle, adenylate kinase 1 (AK1) is responsible for ThTP synthesis. In this study, we show that AK1 knockout mice have normal ThTP levels in skeletal muscle, heart, brain, liver and kidney, demonstrating that AK1 is not responsible for ThTP synthesis in those tissues. We predict that the high ThTP content of particular tissues like the Electrophorus electricus electric organ, or pig and chicken skeletal muscle is more tightly correlated with high ThDP kinase activity or low soluble ThTPase activity than with non-stringent substrate specificity and high activity of adenylate kinase.
authors.affiliation: Center for Cellular and Molecular Neurobiology, University of Liège, 17 place Delcour, Belgium.
authors.forename: Alexander F
authors.initials: AF
authors.lastname: Makarchikov
authors.forename: Pierre
authors.initials: P
authors.lastname: Wins
authors.forename: Edwin
authors.initials: E
authors.lastname: Janssen
authors.forename: Bé
authors.initials: B
authors.lastname: Wieringa
authors.forename: Thierry
authors.initials: T
authors.lastname: Grisar
authors.forename: Lucien
authors.initials: L
authors.lastname: Bettendorff
mesh_terms: D000263:Adenylate Kinase / Q000172:deficiency*; D000818:Animals; D001921:Brain / Q000378:metabolism; D007527:Isoenzymes / Q000172:deficiency*; D007668:Kidney / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D018482:Muscle, Skeletal / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism; D013838:Thiamine Triphosphate / Q000032:analysis / Q000096:biosynthesis / Q000378:metabolism*
chemical_list: D007527:Isoenzymes; D013838:Thiamine Triphosphate; D000263:Adenylate Kinase; C110939:adenylate kinase 1