Modifications and intracellular trafficking of FADD/MORT1 and caspase-8 after stimulation of T lymphocytes

Cell Death Differ. 2004 Jul;11(7):724-36. doi: 10.1038/sj.cdd.4401408.


The adaptor protein FADD/MORT1 is essential for apoptosis induced by 'death receptors', such as Fas (APO-1/CD95), mediating aggregation and autocatalytic activation of caspase-8. Perhaps surprisingly, FADD and caspase-8 are also critical for mitogen-induced proliferation of T lymphocytes. We generated novel monoclonal antibodies specific for mouse FADD and caspase-8 to investigate whether cellular responses, apoptosis or proliferation, might be explained by differences in post-translational modification and subcellular localisation of these proteins. During both apoptosis signalling and mitogenic activation, FADD and caspase-8 aggregated in multiprotein complexes and formed caps at the plasma membrane but they did not colocalise with lipid rafts. Interestingly, mitogenic stimulation, but not Fas ligation, induced a unique post-translational modification of FADD. These different modifications may determine whether FADD and caspase-8 induce cell death or proliferation.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adaptor Proteins, Signal Transducing / chemistry
  • Adaptor Proteins, Signal Transducing / genetics
  • Adaptor Proteins, Signal Transducing / metabolism*
  • Amino Acid Sequence
  • Animals
  • Antibodies, Monoclonal / metabolism
  • Apoptosis
  • Blotting, Western
  • Caspase 8
  • Caspases / genetics
  • Caspases / metabolism*
  • Cell Division
  • Cell Line
  • Cells, Cultured
  • Epitopes
  • Fas-Associated Death Domain Protein
  • Glutathione Transferase / metabolism
  • Humans
  • Hybridomas / metabolism
  • Lymphocyte Activation*
  • Mice
  • Microscopy, Fluorescence
  • Protein Processing, Post-Translational
  • Protein Structure, Tertiary
  • Protein Transport
  • Rats
  • Rats, Wistar
  • Recombinant Fusion Proteins / metabolism
  • Stem Cells / cytology
  • T-Lymphocytes / metabolism*
  • fas Receptor / metabolism


  • Adaptor Proteins, Signal Transducing
  • Antibodies, Monoclonal
  • Epitopes
  • FADD protein, human
  • Fadd protein, mouse
  • Fadd protein, rat
  • Fas-Associated Death Domain Protein
  • Recombinant Fusion Proteins
  • fas Receptor
  • Glutathione Transferase
  • CASP8 protein, human
  • Casp8 protein, mouse
  • Casp8 protein, rat
  • Caspase 8
  • Caspases