Calpain small subunit 2 (CAPNS2)

Calpain small subunit 2 (CAPNS2) is a calcium-binding regulatory subunit within the calpain complex, a family of intracellular, non-lysosomal, calcium-dependent cysteine proteases. Unlike the ubiquitous calpain small subunit 1 (CAPNS1), CAPNS2 is tissue-specific, developmentally regulated, and possesses unique sequence and binding features. It acts primarily as a modulatory partner that supports the proper folding and calcium-dependent activation of the calpain large catalytic subunit, influencing substrate specificity in a manner distinct from the canonical subunit. CAPNS2 does not undergo the typical autolytic conversion seen with other calpain small subunits and is thought to have specialized roles in modulating calpain activity under different physiological conditions. Genetic association studies suggest a role in thyroid hormone metabolism and possibly other tissue-specific functions. Key context and caveats: - There is potential confusion between CAPNS2 (the uncommon, less-studied calpain small subunit 2) and CAPNS1 (the major, conventional small regulatory subunit found in the main calpain-1 and calpain-2 complexes). - CAPNS2 is not the catalytic subunit; it is a regulatory component and is not itself considered a canonical drug target. - Therapeutic targeting in the calpain field centers on the large catalytic subunits (CAPN1, CAPN2), which are directly involved in pathologies such as cancer, neurodegeneration, and cardiovascular disease. - There are no known drugs, biomarkers, or direct safety issues related to CAPNS2 as a drug target. If you seek information on the therapeutic targeting of calpains, the relevant targets are calpain-1 (CAPN1) and calpain-2 (CAPN2), not CAPNS2. Conclusion: - CAPNS2 is a regulatory protein important for modulating calpain activity, but is not a direct therapeutic target. - If your interest is in calpain enzyme inhibition or disease relevance, review the properties of the catalytic subunits (CAPN1/CAPN2), not CAPNS2. - The target as listed is not suitable for therapeutic targeting in the usual sense (hence, is_incorrect: true).

Other names

Calpain small subunit 2CAPNS2CSS2MGC12536MGC14804calcium-dependent protease small subunit 2calpain regulatory subunit 2