Lysyl-tRNA synthetase（KARS) is a member of the class-II aminoacyl-tRNA synthetase family. KARS exists as both mitochondrial and cytoplasmic isoforms produced by alternative splicing， and believed to have a role in autoimmune diseases， such as polymyositis or dermatomyositis. The KARS protein functions to catalyze the aminoacylation of tRNAs by their corresponding amino acids， so linking amino acids with tRNA-contained nucleotide triplets.
