Fig. 6
From: APC/CCDH1 synchronizes ribose-5-phosphate levels and DNA synthesis to cell cycle progression
APC/CCDH1 regulates R5P and nucleotide levels by controlling TKTL1 levels. a, b Relative levels of total, M1, and M2 R5P-containing metabolites were compared between (a) HEK293T and TKTL1-overexpressing HEK293T cells and between (b) HEK293T and CDH1-knockdown (siRNA) HEK293T cells. Total levels of R5P-containing metabolites in untreated cells were set as 100%. The significance between level changes in M1 and M2 species was analyzed. Data are presented as mean ± SEM, Student’s t test, ns not significant vs the corresponding control group. c, d R5P levels in HeLa cells were compared with that of (c) CDH1-knockout HeLa cells and (d) CDH1-overexpressing HeLa cells. Cell cycle phases were achieved by double thymidine blocking followed by release; R5P levels in the initial G1 phase were arbitrarily set as 100%. Data are shown by means ± SEM of three independent experiments. e, f The effects of CDH1 overexpression and CDH1 knockdown on levels of R5P-containing metabolites were determined in (e) HEK293T and TKTL1-knockdown HEK293T cells as well as in (f) HeLa and TKTL1-knockdown HeLa cells. Data are presented by means ± SEM of three independent experiments, Student’s t test, ***p < 0.001, **p < 0.01, *p < 0.05, ns not significant vs the corresponding control group. g, h The effects of (g) CDH1 overexpression and (h) CDH1 knockdown on the levels of R5P-containing metabolites were compared in HEK293T and HeLa cells (empty bars) as well as in TKTL1-knockdown HEK293T and HeLa cells (blue bars), respectively. Nucleotide levels in untreated HEK293T and HeLa cells were arbitrarily set as 100%. Data are presented by means ± SEM of three independent experiments, Student’s t test, ***p < 0.001, **p < 0.01, *p < 0.05, ns not significant. i PRPS1 mRNA levels were measured in HEK293T cells, TKTL1-overexpressing HEK293T cells, and TKTL1-overexpressing HEK293T cells cultured in 10 mM R5P-supplemented medium. Data are presented as mean ± SEM, Student’s t test, ***p < 0.001, ns not significant vs the corresponding control group. Full-length blots are presented in Supplementary Fig. 10
