Type

Journal Article

Authors

Markus Rehm
Jochen H M Prehn
Michael J Courtney
Heiko Düssmann
Anna-Kaisa Lehtivarjo
Barbara F Kohler
Christian T Hellwig

Subjects

Biochemistry

Topics
tnf related apoptosis inducing ligand pharmacology hela cells kinetics bh3 interacting domain death agonist protein apoptosis cloning molecular fluorescence resonance energy transfer metabolism protein synthesis inhibitors cycloheximide tumor necrosis factor alpha models biological caspases humans mitochondria caspase 8

Real time analysis of tumor necrosis factor-related apoptosis-inducing ligand/cycloheximide-induced caspase activities during apoptosis initiation. (2008)

Abstract Employing fluorescence resonance energy transfer (FRET) imaging, we previously demonstrated that effector caspase activation is often an all-or-none response independent of drug choice or dose administered. We here investigated the signaling dynamics during apoptosis initiation via the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) receptor pathway to investigate how variability in drug exposure can be translated into largely kinetically invariant cell death execution pathways. FRET-based microscopy demonstrated dose-dependent responses of caspase-8 activation and activity within individual living HeLa cells. Caspase-8 on average was activated 45-600 min after TRAIL/cycloheximide addition. Caspase-8-like activities persisted for 15-60 min before eventually inducing mitochondrial outer membrane permeabilization. Independent of the TRAIL concentrations used or the resulting caspase-8-like activities, mitochondrial outer membrane permeabilization was induced when 10% of the FRET substrate was cleaved. In contrast, in Bid-depleted cells, caspase-8-like activity persisted for hours without causing immediate cell death. Our findings provide detailed insight into the intracellular signaling kinetics during apoptosis initiation and describe a threshold mechanism controlling the induction of apoptosis execution.
Collections Ireland -> Royal College of Surgeons in Ireland -> PubMed

Full list of authors on original publication

Markus Rehm, Jochen H M Prehn, Michael J Courtney, Heiko Düssmann, Anna-Kaisa Lehtivarjo, Barbara F Kohler, Christian T Hellwig

Experts in our system

1
Markus Rehm
Royal College of Surgeons in Ireland
Total Publications: 55
 
2
Jochen H M Prehn
Royal College of Surgeons in Ireland
Total Publications: 206
 
3
Heiko Düssmann
Royal College of Surgeons in Ireland
Total Publications: 45
 
4
Christian T Hellwig
Royal College of Surgeons in Ireland
Total Publications: 11