Duration of on-switch of apoptosis in HeLa cells

Value 19 min Range: ±10 min
Organism Human Homo sapiens
Reference Albeck JG, Burke JM, Spencer SL, Lauffenburger DA, Sorger PK. Modeling a snap-action, variable-delay switch controlling extrinsic cell death. PLoS Biol. 2008 Dec 26(12):2831-52 Table - link PubMed ID19053173
Method HeLa cells were exposed to TRAIL over a 500-fold range of concentrations spanning roughly physiological to saturating. Cell death was monitored by live-cell microscopy using either of two Forster resonance energy transfer (FRET)-based reporter proteins whose fluorescence changes upon cleavage (effector or initiator caspase reporter proteins, EC-RP and IC-RP) and a reporter for mitochondrial outer membrane permeabilization (mitochondrial intermembrane space reporter protein [IMS-RP]) whose cytosolic translocation mimics that of Smac and CyC [15]. In FRET, complex formation between two molecules such as DNA-Protein or protein-protein is tracked by attaching a fluorescing molecules, a photon donor and a photon acceptor to each biomolecule of interest. When the donor and acceptor are dissociated the donor's fluorescence is mainly observed and when they are brought to close proximity (1-10 nm) the acceptor's fluorescence is observed. Similarly conformational changes of a protein can be observed when donor and acceptor molecules are attached to two sites on it through genetic engineering. Green Fluorescent Protein variants, CFP and YFP are commonly used as the donor and acceptor.
Comments At physiological level of TRAIL, 2 ng/ml. In table Ts refers to time until switch-on of apoptosis and Td refers to time until cell death
Entered by Uri M
ID 104872