Growth of RCC10 (a) and 786-O (b) cells expressing vector, FBP1, or FBP1 G260R in medium containing 1 mM glucose. HIF reporter activity in RCC4 (c) and 786-O (d) cells ectopically expressing vector, FBP1, FBP1 G260R, FBP1 “R” domain, and FBP1 “C” domain. e, Western blot analysis of V5-tagged proteins and actin in 293T cells expressing vector, V5-FBP1, V5-FBP1 G260R, and indicated V5-FBP1 exon truncations. A schematic representation of FBP1 exons is shown above both blots. Note that the FBP1 “R” domain is encoded by exons 1 to 4, while the “C” domain by exons 5 to 7. f, FBP1 enzymatic activity in 293T cells expressing indicated constructs as shown in (e). g, HIF reporter activity in RCC10 cells expressing indicated constructs as shown in (e). h, Lysates of 293T cells expressing V5-FBP1 and HA-HIF1α (P402A/P564A double mutant) were immunoprecipitated with IgG or V5 antibody and blotted for HA. i, Lysates of RCC10 cells expressing V5-FBP1 were immunoprecipitated with IgG or V5 antibody and blotted for endogenous HIF1α. Experiments were repeated twice. Values represent mean±s.d. (technical triplicates from a representative experiment) *p<0.01.