De novo biosynthesis of sterols and fatty acids in the Trypanosoma brucei procyclic form: Carbon source preferences and metabolic flux redistributions
Fig 6
Metabolic flux redistribution between the sterol and fatty acid biosynthetic pathways.
(A) Western blot analyses of the parental (WT), knock-out and tetracycline-induced (.i) or non-induced (.ni) mutant cell lines with the immune sera indicated in the right margin. (B) The top and lower parts represent the relative incorporation of radio-labelled carbon sources (D-[U-14C]-glucose, L-[U-14C]-threonine, [1-14C]-acetate and L-[U-14C]-leucine) into fatty acids and sterols, respectively, of tetracycline-induced (.i) and non-induced (.ni) RNAiTDH, RNAiTDH/RNAiPDH, and Δpdh cell lines, compared to the parental cell line (PCL). [14C]-labelled fatty acid methyl esters and sterols were separated by HPTLC and analyzed as described in the Materials and mehods section. Data are normalized with the parental cell (PCL) values with an arbitrary value of 100 for the PCL samples, which is represented by a horizontal dashed lane. The arrows highlight reduction of radio-label incorporation into lipids expected from the metabolic map in Fig 1. Error bars indicate mean ± SD of 3 biological replicates. nd: not detectable.