Plays a role in resistance to arsenite (PubMed:23593298). May play a role in the oxidative stress response induced by reactive oxygen species produced during infection by pathogenic bacteria (PubMed:22216003). Together with trxr-1, required for the reduction of disulfide groups in the cuticle during molting (PubMed:21199936). ATP + L-cysteine + L-glutamate = ADP + gamma-L-glutamyl-L-cysteine + H(+) + phosphate Sulfur metabolism; glutathione biosynthesis; glutathione from L-cysteine and L-glutamate: step 1/2. Expressed in intestine upon arsenite treatment. By oxidative stress such as arsenite treatment. RNAi-mediated knockdown of gsr-1 in mutants lacking trxr-1 causes an arrest during larval molting characterized by a partial detachment of the old cuticle and an impaired ability to reduce cuticle components. Also results in growth arrest during the postdauer molt (PubMed:21199936). RNAi-mediated knockdown causes a severe loss of viability upon arsenite treatment (PubMed:23593298). Belongs to the glutamate--cysteine ligase type 3 family.