Artemis (protein)

Artemis is a protein, also known as DNA cross-link repair 1C protein or DCLRE1C, encoded by the DCLRE1C gene in humans. It is a component of the DNA double-strand break repair pathway, specifically involved in the non-homologous end joining (NHEJ) pathway.

Artemis functions as a DNA repair endonuclease. Its activity is dependent on phosphorylation by DNA-dependent protein kinase catalytic subunit (DNA-PKcs). Upon phosphorylation, Artemis acquires the ability to open hairpin structures formed during V(D)J recombination, a process crucial for generating the diversity of immunoglobulin and T cell receptor genes in developing lymphocytes.

Mutations in the DCLRE1C gene lead to a form of severe combined immunodeficiency (SCID) characterized by sensitivity to ionizing radiation. This condition, sometimes referred to as radiosensitive SCID or ART-SCID, results from the impaired ability to repair DNA double-strand breaks, particularly those induced by radiation exposure. Patients with ART-SCID exhibit a significant deficiency in T and B lymphocytes, rendering them highly susceptible to infections. Diagnosis typically involves assessing T and B cell counts and evaluating cellular radiosensitivity. Treatment options often include hematopoietic stem cell transplantation (HSCT).