tRNA Histidine Guanylyltransferase 1 Like Protein (THG1L)

THG1L, Belongs to the tRNA(His) guanylyltransferase family.Expressed in many tissues. The essential Saccharomyces cerevisiae tRNA(His) guanylyltransferase (Thg1p) is responsible for the unusual G(-1) addition to the 5' end of cytoplasmic tRNA(His). tRNA(His) from Thg1p-depleted cells is uncharged, although histidyl tRNA synthetase is active and the 3' end of the tRNA is intact, suggesting that G(-1) is a critical determinant for aminoacylation of tRNA(His) in vivo. Thg1p depletion leads to activation of the GCN4 pathway, most, but not all, of which is Gcn2p dependent, and to the accumulation of tRNA(His) in the nucleus. Surprisingly, tRNA(His) in Thg1p-depleted cells accumulates additional m(5)C modifications, which are delayed relative to the loss of G(-1) and aminoacylation.