Caspase 3

Caspase 3 is a central executioner caspase in apoptosis, where initiator caspase 9 activates executioner caspases 3 and 7 by proteolysis^[1]. Mechanistically, caspase 3 cleaves caspase 9 at Asp330 and enhances apoptosis by relieving XIAP-mediated inhibition, rather than directly activating caspase 9^[1]. This places caspase 3 within apoptosome-linked feedback control and inhibitor-of-apoptosis regulation, while preserving a distinct functional profile from caspase 7^[1][2]. Compared with caspase 7, caspase 3 can cleave caspase 9 under physiologically relevant conditions, and engineered activation studies show that caspase 3 or caspase 7, but not caspase 6 alone, is sufficient to induce apoptosis^[1][2]. In disease models, caspase 3 and caspase 7 deletion did not reduce infarct size or ventricular remodeling after transient myocardial ischemia-reperfusion, limiting assumptions about canonical caspase-dependent apoptosis in adult cardiomyocytes^[3]. In prostate cancer samples, procaspase 3 and cleaved caspase 3 predicted biochemical progression after radical prostatectomy, supporting their use as apoptosis-related tumor markers^[4]. For experimental applications, caspase 3 research benefits from isoform-aware probes because common DEVD-based peptide inhibitors and substrates cannot reliably distinguish caspase 3 from caspase 7^[5].