title: Functional dissociation of DeltaPsim and cytochrome c release defines the contribution of mitochondria upstream of caspase activation during granzyme B-induced apoptosis.
abstract: Loss of Bid confers clonogenic survival to granzyme B-treated cells, however the exact role of Bid-induced mitochondrial damage--upstream or downstream of caspases--remains controversial. Here we show that direct cleavage of Bid by granzyme B, but not caspases, was required for granzyme B-induced apoptosis. Release of cytochrome c and SMAC, but not AIF or endonuclease G, occurred in the absence of caspase activity and correlated with the onset of apoptosis and loss of clonogenic potential. Loss of mitochondrial trans-membrane potential (DeltaPsim) was also caspase independent, however if caspase activity was blocked the mitochondria regenerated their DeltaPsim. Loss of DeltaPsim was not required for rapid granzyme B-induced apoptosis and regeneration of DeltaPsim following cytochrome c release did not confer clonogenic survival. This functional dissociation of cytochrome c and SMAC release from loss of DeltaPsim demonstrates the essential contribution of Bid upstream of caspase activation during granzyme B-induced apoptosis.
authors.affiliation: Cancer Cell Death, Peter MacCallum Cancer Centre, Locked Bag 1, A'Beckett Street, Melbourne, Victoria 8006, Australia. nigel.waterhouse@petermac.org
authors.forename: N J
authors.initials: NJ
authors.lastname: Waterhouse
authors.forename: K A
authors.initials: KA
authors.lastname: Sedelies
authors.forename: V R
authors.initials: VR
authors.lastname: Sutton
authors.forename: M J
authors.initials: MJ
authors.lastname: Pinkoski
authors.forename: K Y
authors.initials: KY
authors.lastname: Thia
authors.forename: R
authors.initials: R
authors.lastname: Johnstone
authors.forename: P I
authors.initials: PI
authors.lastname: Bird
authors.forename: D R
authors.initials: DR
authors.lastname: Green
authors.forename: J A
authors.initials: JA
authors.lastname: Trapani
mesh_terms: D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D017209:Apoptosis; D051033:Apoptosis Inducing Factor / Q000378:metabolism; D051023:BH3 Interacting Domain Death Agonist Protein / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone / Q000494:pharmacology; D053148:Caspase 3; D061945:Caspase Inhibitors; D020169:Caspases / Q000378:metabolism*; D002470:Cell Survival / Q000187:drug effects; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D045304:Cytochromes c / Q000378:metabolism*; D053804:Granzymes; D006367:HeLa Cells; D006801:Humans; D019169:Jurkat Cells; D008562:Membrane Glycoproteins; D008564:Membrane Potentials; D008928:Mitochondria / Q000187:drug effects / Q000201:enzymology / Q000502:physiology*; D010446:Peptide Fragments / Q000235:genetics / Q000378:metabolism; D054353:Perforin; D052899:Pore Forming Cytotoxic Proteins; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism; D012697:Serine Endopeptidases; D014162:Transfection; D014410:Tumor Stem Cell Assay; D014475:Uncoupling Agents / Q000494:pharmacology
chemical_list: D000590:Amino Acid Chloromethyl Ketones; D051033:Apoptosis Inducing Factor; D051023:BH3 Interacting Domain Death Agonist Protein; C494814:BID protein, human; D061945:Caspase Inhibitors; D015853:Cysteine Proteinase Inhibitors; D008562:Membrane Glycoproteins; D010446:Peptide Fragments; D052899:Pore Forming Cytotoxic Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D014475:Uncoupling Agents; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; D054353:Perforin; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone; D045304:Cytochromes c; C509213:GZMB protein, human; D053804:Granzymes; D012697:Serine Endopeptidases; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases