Caspase-2 is activated at the CD95 death-inducing signaling complex in the course of CD95-induced apoptosis

• Published in: Blood 2006-07, Vol.108 (2), p.559-565
• Main Authors: Lavrik, Inna N., Golks, Alexander, Baumann, Simone, Krammer, Peter H.
• Format: Article
• Language: English
• Subjects: Apoptosis; B-Lymphocytes; Biological and medical sciences; Caspase 2; Caspases - metabolism; Caspases - physiology; Cell Line, Tumor; Death Domain Receptor Signaling Adaptor Proteins; Enzyme Activation; Enzyme Precursors - metabolism; fas Receptor - metabolism; fas Receptor - physiology; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Humans; Immunobiology; Lymphoid cells: ontogeny, maturation, markers, receptors, circulation and recirculation; Signal Transduction; T-Lymphocytes; Tumor Necrosis Factor Receptor-Associated Peptides and Proteins - metabolism
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood-2005-07-007096

Caspase-2 was reported to be involved in a number of apoptotic pathways triggered by various stimuli. However, the molecular mechanism of procaspase-2 activation in the course of apoptosis remains poorly defined. In this report, we demonstrate that procaspase-2 is recruited to the CD95 (Fas/APO-1) death-inducing signaling complex (DISC) in human T- and B-cell lines. We show that procaspase-2 is activated at the DISC on CD95 stimulation. Despite its presence at the DISC, caspase-2 does not initiate apoptosis on CD95 stimulation in caspase-8–deficient cell lines. Taken together, our data reveal that caspase-2 is activated at the DISC but does not play an initiating role in the CD95-induced apoptosis.