Fig. 1: Metabolite screening by TRACE assay reveals purine nucleoside supplementation inhibits telomerase reverse transcriptase activity in human cells.

a Diagram of TRACE assay. b Terminal restriction fragment Southern blot (TRF) from TRACE assay performed as follows: TERC−/− 293 T cells were transfected with the indicated expression vectors, cultured for 18 h, then split and harvested at the indicated timepoints after splitting. The results represent a single experiment. c–g TRFs from TRACE assay where cells were transfected as in b. 18 h after transfection, cells were split and supplemented as indicated for 30 h prior to harvesting. h Quantification of TRACE assays from c–g, and Supplementary Fig. 1i-k, displayed as the relative telomere synthesis compared to untreated cells. i Quantification of TRACE assay. Cells were treated with the indicated compounds at the following doses: dG, 100 μM; all other compounds, 500 μM. Experiment performed in biological triplicate. P values compared with untreated cells were calculated using RM one-way ANOVA with Geisser-Greenhouse correction and Dunnett’s multiple comparison test. Includes data from c–h and Supplementary Fig. 1i–k.j Quantification of data from f, performed in biological triplicate. In i-j, data are presented as means; error bars indicate s.d. rC, cytidine; rU, uridine; dC, deoxycytidine; dA, deoxyadenosine; rA, adenosine; rG, guanosine. Source data are provided as a Source Data file.