Figure 4: N-terminal arginylation differentially affects protein stability of PRPS1 and PRPS2. | Nature Communications

Figure 4: N-terminal arginylation differentially affects protein stability of PRPS1 and PRPS2.

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

Figure 4

(a) Linear maps of the recombinant constructs representing constitutively non-arginylated or arginylated forms of PRPS1/2. When expressed in vivo, the N-terminal ubiquitin moiety is removed during translation by de-ubiquitinating (De-Ub) enzymes, exposing the Met (M-) or Arg (R-) at the protein’s N-terminus (arrowheads). (b) Left: representative immunoblots of the steady-state levels of non-arginylated (M-) and constitutively arginylated (R-) recombinant PRPS expressed as GFP fusions in HEK293T cells. The concentration of specific mRNA in each sample was quantified by quantitative PCR using GFP-specific primers and actin primers as control and then normalized to the values of the R- samples separately for PRPS1 or PRPS2. Right: average steady-state levels of M- and R- PRPS1 and PRPS2 proteins per unit of specific mRNA in vivo. The value of R-PRPS1 was normalized to that of M-PRPS1. Similarly, R-PRPS2 was normalized to M-PRPS2. Error bars represent s.e.m. (PRPS1/2: n=4).

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