title: Mitochondrial thymidine kinase 2 but not deoxyguanosine kinase is up-regulated during the stationary growth phase of cultured cells.
abstract: Mitochondrial thymidine kinase 2 (TK2) and deoxyguanosine kinase (dGK) catalyze the initial phosphorylation of pyrimidine and purine deoxyribonucleosides, and are essential for maintaining mitochondrial dNTP pools for mitochondrial DNA replication. Here the expression of mitochondrial TK2 and dGK in relation to cell growth phases in cultured cells was investigated. TK2 and dGK protein levels in isolated mitochondria and TK2 activity in total cell extracts from U2OS and TK1 deficient L929 cells were determined. We found that TK2 levels were negatively correlated with cell growth rates and there was an exponential increase in TK2 levels in cells entering stationary phase. The expression of dGK did not change and appeared to be constitutive.
authors.affiliation: a Department of Anatomy, Physiology and Biochemistry , Swedish University of Agricultural Sciences , BMC , Uppsala , Sweden.
authors.forename: Ren
authors.initials: R
authors.lastname: Sun
authors.forename: Staffan
authors.initials: S
authors.lastname: Eriksson
authors.forename: Liya
authors.initials: L
authors.lastname: Wang
mesh_terms: D000818:Animals; D002460:Cell Line; D049109:Cell Proliferation; D006801:Humans; D051379:Mice; D008928:Mitochondria / Q000201:enzymology*; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000378:metabolism*; D013937:Thymidine Kinase / Q000378:metabolism*; D015854:Up-Regulation
chemical_list: D017853:Phosphotransferases (Alcohol Group Acceptor); C105339:thymidine kinase 2; C019165:deoxyguanosine kinase; D013937:Thymidine Kinase
keywords: Thymidine kinase 2; deoxyguanosine kinase; expression profile