of plasmid DNA was transfected into each well using Lipofecta- mine 2000 as described. Found at: doi:10.1371/journal.pone.0013823.s008 (1.33 MB TIF) Acknowledgments We thank Dr. Graeme Bell (University of Chicago) for the HKIII plasmid and Dr. Mircea Ivan (Indiana University) for the HIF plasmids. We would References 1. Bell GI, Burant CF, Takeda J, Gould GW (1993) Structure and function of mammalian facilitative sugar transporters. J Biol Chem 268: 19161–19164. 2. Gould GW, Holman GD (1993) The glucose transporter family: structure, function and tissue-specific expression. Biochem J 295(Pt 2): 329–341. 3. Mueckler M (1994) Facilitative glucose transporters. Eur J Biochem 219: 713–725. 4. Printz RL, Osawa H, Ardehali H, Koch S, Granner DK (1997) Hexokinase II gene: structure, regulation and promoter organization. Biochem Soc Trans 25: 107–112. 5. Middleton RJ (1990) Hexokinases and glucokinases. Biochem Soc Trans 18: 180–183. 6. 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