Figure 3: The enzymatic activity of PRPS2 is increased by N-terminal arginylation. | Nature Communications

Figure 3: The enzymatic activity of PRPS2 is increased by N-terminal arginylation.

From: Arginylation regulates purine nucleotide biosynthesis by enhancing the activity of phosphoribosyl pyrophosphate synthase

Figure 3

(a) Immunoblots of WT and Ate1 KO cell lysates probed with anti-PRPS and -β-actin as a loading control show that endogenous PRPS levels are higher in Ate1 KO cells compared with WT, opposite to the metabolic effects in these cells that suggest a reduction in PRPS function. (b) Total PRPS activity measured as AMP levels in WT and Ate1 KO cell extracts, normalized to PRPS levels shown in a. Ate1 KO cells have reduced total PRPS activity. (c) Normalized unit activity of non-arginylated (M-) and arginylated (R-) PRPS2 activity measured as AMP levels in soluble extracts from HEK293T cells transfected with non-arginylated or constitutively arginylated GFP-fused PRPS2 (M-PRPS2-GFP and R-PRPS2-GFP, respectively) (see also Supplementary Table 1). For each measurement, the levels of endogenous PRPS activity in untransfected cells was determined in the same experiment and subtracted from the total values, which were further normalized by the concentrations of the GFP-fused recombinant PRPS2 to reflect only the comparative unit activity of the expressed M- or R-PRPS2. Error bars represent s.e.m. (n=3). **P<0.01; *P<0.05.

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