Altered Expression of Conventional Calpains Influences Apoptosis

摘要: Calpains are non-lysosomal, cysteine proteases ubiquitously expressed in animal cells. Most cells also express an inhibitor protein, calpastatin, that is highly specific for calpains. Among many proposed functions, calpains thought to participate apoptosis signaling through various pathways. studies of calpain function have relied on methodologies cannot separate the influence conventional (μ- and m-calpains) from other family members, or non-calpain some cases. The present investigation addresses this issue by unambiguously altering abundance cultured cells, determining effect models apoptosis. Overexpression μ-calpain enhanced Chinese hamster ovary (CHO) response calcium ionophore A23187, sarcolemma Ca2+-pump inhibitor, thapsigargin, serum deprivation. calpastatin had opposite effect. Altered expression no detectable caused expo-sure H2O2, ultraviolet light, protein kinase staurosporine. Increased protected against TNF-alpha triggered These results demonstrate calpain/calpastatin balance important forms CHO but not others. Moreover, pathway a protective effect, as previously (Han, Y., et al., 1999).