Involved in protein synthesis (PubMed:23076791). Catalyzes the specific attachment of an amino acid to its cognate tRNA in a 2 step reaction: the amino acid (AA) is first activated by ATP to form AA-AMP and then transferred to the acceptor end of the tRNA. ATP + L-leucine + tRNA(Leu) = AMP + diphosphate + L-leucyl-tRNA(Leu) RNAi-mediated knockdown results in an increase in the expression of gpdh-1 independent of hypertonic stress. Belongs to the class-I aminoacyl-tRNA synthetase family.