title: Degradomics reveals that cleavage specificity profiles of caspase-2 and effector caspases are alike.
abstract: Caspase-2 is considered an initiator caspase because its long prodomain contains a CARD domain that allows its recruitment and activation in several complexes by homotypic death domain-fold interactions. Because little is known about the function and specificity of caspase-2 and its physiological substrates, we compared the cleavage specificity profile of recombinant human caspase-2 with those of caspase-3 and -7 by analyzing cell lysates using N-terminal COmbined FRActional DIagonal Chromatography (COFRADIC). Substrate analysis of the 68 cleavage sites identified in 61 proteins revealed that the protease specificities of human caspases-2, -3, and -7 largely overlap, revealing the DEVD↓G consensus cleavage sequence. We confirmed that Asp(563) in eukaryotic translation initiation factor 4B (eIF4B) is a cleavage site preferred by caspase-2 not only in COFRADIC setup but also upon co-expression in HEK 293T cells. These results demonstrate that activated human caspase-2 shares remarkably overlapping protease specificity with the prototype apoptotic executioner caspases-3 and -7, suggesting that caspase-2 could function as a proapoptotic caspase once released from the activating complex.
authors: Department for Molecular Biomedical Research, Flanders Institute for Biotechnology (VIB), Ghent University, B-9052 Ghent (Zwijnaarde), Belgium.
authors: Magdalena
authors: M
authors: Wejda
authors: Francis
authors: F
authors: Impens
authors: Nozomi
authors: N
authors: Takahashi
authors: Petra
authors: P
authors: Van Damme
authors: Kris
authors: K
authors: Gevaert
authors: Peter
authors: P
authors: Vandenabeele
mesh_terms: D017209:Apoptosis / Q000502:physiology*; D053143:Caspase 2 / Q000235:genetics / Q000378:metabolism*; D053148:Caspase 3 / Q000235:genetics / Q000378:metabolism*; D053179:Caspase 7 / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D003546:Cysteine Endopeptidases / Q000235:genetics / Q000378:metabolism*; D039642:Eukaryotic Initiation Factors / Q000235:genetics / Q000378:metabolism*; D057809:HEK293 Cells; D006801:Humans; D017434:Protein Structure, Tertiary; D059748:Proteolysis
chemical_list: D039642:Eukaryotic Initiation Factors; C031799:eIF-4B; C490360:CASP2 protein, human; C505407:CASP3 protein, human; C505520:CASP7 protein, human; D053143:Caspase 2; D053148:Caspase 3; D053179:Caspase 7; D003546:Cysteine Endopeptidases