tRNA Isopentenyltransferase 1 (TRIT1)

tRNA-isopentenyltransferase (tRNA-IPT) catalyses the addition of N⁶-isopentenyladenosine (i⁶A) on residue 37 of tRNA molecules that bind codons starting with uridine. The human tRNA-isopentenyltransferase (TRIT1) gene encodes a complex pattern of mRNA variants through alternative splicing in both normal and tumor lung tissue and that the nonsense suppressor activity of tRNA-IPT is maintained only in the full-length mRNA isoform, as revealed by gene complementation in yeast. Expression of the full-length transcript was down-regulated 6–14-fold in lung adenocarcinomas as compared to normal lung tissue. A549 lung cancer cells transfected to express the functional TRIT1 gene formed significantly smaller colonies with reduced scattering on the edges and had only limited ability to induce tumors in nude mice.