Protein, RNA, and Gene Expression Analysis

Extraction of total protein and RNA were performed according to standard protocols (19 (link), 23 (link)). The primary antibodies used in this study included CPS1 (Proteintech, #18703-1-AP), AOX1 (Proteintech, # 19495-1-AP), OXCT1 (Proteintech, #12175-1-AP), NME4 (Bioworld, #BS71176) and β-Actin (CST, #4967). Oligonucleotide primers used for detection of human-TRDMT1, SMS, UAP1, WARS2, PLOR3G, NNT, GAPDH (21 (link)) were described in Supplementary Figure S3. Cycle threshold (Ct) values of target gene cDNA were normalized to GAPDH using the −2ΔΔCt method. All the reactions were performed in triplicate for each sample.