Enables glutamate-cysteine ligase activity. Involved in several processes, including cellular response to growth factor stimulus; cellular response to hormone stimulus; and cellular response to mechanical stimulus. Part of glutamate-cysteine ligase complex. Used to study liver cirrhosis and pulmonary emphysema. 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]