Enables glutamate-cysteine ligase activity. Acts upstream of or within several processes, including glutathione biosynthetic process; negative regulation of apoptotic signaling pathway; and regulation of cellular protein metabolic process. Located in cytosol. Part of glutamate-cysteine ligase complex. Is expressed in several structures, including alimentary system; central nervous system; integumental system; sensory organ; and urinary system. Used to study cataract. Human ortholog(s) of this gene implicated in cystic fibrosis; glutamate-cysteine ligase deficiency; hemolytic anemia; and myocardial infarction. Orthologous to human GCLC (glutamate-cysteine ligase catalytic subunit). [provided by Alliance of Genome Resources, Apr 2022]