Among the transcripts with the most consistent trans-QTLs are glycyl-tRNA synthetase (Gars), cysteinyl-tRNA synthetase (Cars), asparaginyl-tRNA synthetase (Nars), isoleucyl tRNA synthetase (Iars), asparagine synthetase (Asns), and activating transcription factor 4 (Atf4). These transcripts map to Qrr1 in almost all datasets in which the strong trans-effect is detected. Gars, Cars, and Nars are aminoacyl-tRNA synthetases (ARS) that charge tRNAs with amino acids during translation. Asns and Atf4 are also involved in amino acid metabolism—Asns is required for asparagine synthesis and is under the regulation of Atf4, which in turn is sensitive to cellular amino acid levels [53]. Other transcripts that consistently map as trans-QTLs to Qrr1 include brain expressed X-linked 2 (Bex2), splicing factor Sfrs3, ribonucleoproteins Snrpc and Snrpd1, ring finger protein 6 (Rnf6), and RAS oncogene family member Rab2.
