Caspase-2 is an initiator caspase responsible for pore-forming toxin-mediated apoptosis

Autor: F. Gisou van der Goot, Gergely Imre, Volker Dötsch, Matthias Husmann, Krishnaraj Rajalingam, Douglas R. Green, Bernd Thiede, Armelle-Natsuo Takeda, Dagmar Meyer zu Heringdorf, Bhanu Sinha, Jan Heering
Rok vydání: 2012
Předmět:
Zdroj: The EMBO Journal. 31:2615-2628
ISSN: 0261-4189
DOI: 10.1038/emboj.2012.93
Popis: Bacterial pathogens modulate host cell apoptosis to establish a successful infection. Pore-forming toxins (PFTs) secreted by pathogenic bacteria are major virulence factors and have been shown to induce various forms of cell death in infected cells. Here we demonstrate that the highly conserved caspase-2 is required for PFT-mediated apoptosis. Despite being the second mammalian caspase to be identified, the role of caspase-2 during apoptosis remains enigmatic. We show that caspase-2 functions as an initiator caspase during Staphylococcus aureus alpha-toxin- and Aeromonas aerolysin-mediated apoptosis in epithelial cells. Downregulation of caspase-2 leads to a strong inhibition of PFT-mediated apoptosis. Activation of caspase-2 is PIDDosome-independent, and endogenous caspase-2 is recruited to a high-molecular-weight complex in alpha-toxin-treated cells. Interestingly, prevention of PFT-induced potassium efflux inhibits the formation of caspase-2 complex, leading to its inactivation, thus resisting apoptosis. These results revealed a thus far unknown, obligatory role for caspase-2 as an initiator caspase during PFT-mediated apoptosis. The EMBO Journal (2012) 31, 2615-2628. doi: 10.1038/emboj.2012.93; Published online 24 April 2012
Databáze: OpenAIRE
Externí odkaz: