Figure 8.
ASNS substrate and product abundance in JRS cells expressing ASNS variants. Stable cell lines were generated from ASNS-null JRS cells transduced to express WT, G373V, or R519H variant ASNS protein. Each cell line was incubated in DMEM ± Asn for 24 h followed by collection of cell extracts and amino acid analysis by GC-MS. The results for Asn, Asp, Gln, and Glu are presented as “arbitrary units,” calculated as the averages of triplicate determinations ± SDs of the relative amount of each amino acid per 106 cells. To illustrate the relative changes for Asn more clearly, the ratios of the values for DMEM-Asn/DMEM+Asn were calculated for each cell line and are shown as an insert. Where not shown, the SD marks are within the bar and an asterisk indicates that the p value was ≤ 0.05 compared to the value obtained for the cells expressing WT ASNS. ASNS, asparagine synthetase; JRS, Jensen rat sarcoma.