Extended Data Figure 7. Nuclear FBP1 co-localizes with HIF at HREs and inhibits HIF activity.

a, ChIP assays evaluating FBP1 chromatin binding to HREs in the PDK1, LDHA, and VEGF promoters. b, ChIP-reChIP analysis examining the co-localization of HIF1α and FBP1 at HREs in the GLUT1, PDK1, LDHA, and VEGF promoters. c, FBP1 protein levels detected in cytosolic and nuclear fractions of human kidney tissue. HDAC1, a nuclear protein, and HSP90, a cytosolic protein, reflect the purity of respective subcellular fractionations. d, Immunofluorescent staining of human kidney tissue (interstitial region) with FBP1 antibody. Rabbit IgG was used as a negative control, and DAPI is a fluorescent nuclear dye. e, Western blot analysis of V5-tagged FBP1 or FBP1 NES (FBP1 linked to a C-terminal nuclear export sequence) in the cytosolic and nuclear fractions of transfected RCC10 cells. f, qRT-PCR analysis of HIF target genes in RCC10 cells expressing vector, FBP1, or FBP1 NES. Glucose uptake (g) and lactate secretion (h) in RCC10 cells expressing vector, FBP1, or FBP1 NES. i, Models depicting the metabolic status of normal kidney proximal tubular epithelial cells (left), and VHL-deficient ccRCC tumour cells where FBP1 expression is inhibited (right). Error bars represent s.d. except in (a) and (b), which indicate s.e.m. Error bars were calculated based on three technical replicates from a representative experiment, and experiments were repeated twice to confirm the results. *p<0.05.