Portal de Periódicos da CAPES

Characterization of Cytoplasmic Caspase-2 Activation by Induced Proximity

2009; Elsevier BV; Volume: 35; Issue: 6 Linguagem: Inglês

10.1016/j.molcel.2009.07.023

1097-4164

Lisa Bouchier‐Hayes, Andrew Oberst, Gavin P. McStay, Samuel Connell, Stephen W. G. Tait, Christopher P. Dillon, Jonathan M. Flanagan, Helen M. Beere, Douglas R. Green,

Bacillus and Francisella bacterial research

Caspase-2 is an initiator caspase activated in response to heat shock and other stressors that induce apoptosis. Activation of caspase-2 requires induced proximity resulting after recruitment to caspase-2 activation complexes such as the PIDDosome. We have adapted bimolecular fluorescence complementation (BiFC) to measure caspase-2 induced proximity in real time in single cells. Nonfluorescent fragments of the fluorescent protein Venus that can associate to reform the fluorescent complex were fused to caspase-2, allowing visualization and kinetic measurements of caspase-2 induced proximity after heat shock and other stresses. This revealed that the caspase-2 activation platform occurred in the cytosol and not in the nucleus in response to heat shock, DNA damage, cytoskeletal disruption, and other treatments. Activation, as measured by this approach, in response to heat shock was RAIDD dependent and upstream of mitochondrial outer-membrane permeabilization. Furthermore, we identify Hsp90α as a key negative regulator of heat shock-induced caspase-2 activation.