Mitogen-activated protein kinase-mediated Fas apoptotic signaling pathway

Mitogen-activated protein kinase-mediated Fas apoptotic signaling pathway

^*Massachusetts General Hospital Cancer Center, Charlestown, MA 02129; ^‡Howard Hughes Medical Institute, University of Massachusetts Medical Center, Worcester, MA 01605; ^§Department of Neurology, Harvard Medical School, Boston, MA 02115; ^¶Millenium Pharmaceuticals, Inc., Cambridge, MA 02139; and ^**Department of Molecular and Cellular Biology/Biological Laboratories, Harvard University, Cambridge, MA 02138

Abstract

Ligation of the cell surface receptor Fas/APO-1 (CD95) by its specific ligand or by anti-Fas antibodies rapidly induces apoptosis in susceptible cells. To characterize the molecular events involved in Fas-induced apoptosis, we examined the contribution of two subgroups of the mitogen-activated protein (MAP) kinase family, the Jun kinases or stress-activated protein kinases (JNKs/SAPKs) and the extracellular signal-regulated kinases (ERKs), in a Fas-sensitive neuroblastoma cell line. Here we show that both JNK and ERK protein kinases were activated upon Fas crosslinking through a Ras-dependent mechanism. Interference with either the JNK or ERK pathway by ectopic expression of dominant-interfering mutant proteins blocked Fas-mediated apoptosis. ERK activation was transient and associated with induced expression of the Fas receptor. In contrast, JNK activation was sustained and correlated with the onset of apoptosis. These data indicate that the ERK and the JNK groups of MAP kinases cooperate in the induction of cell death by Fas. Inhibition of Fas killing by an interleukin 1β-converting enzyme (ICE)-like protease inhibitor peptide did not modify Fas-induced JNK activation upon Fas ligation. In contrast, changes in Bcl-2 level due to expression of sense and antisense vectors influenced the sensitivity to Fas killing and Fas-induced JNK activation.

Footnotes

↵ † Present address: Laboratoire de Biologie Moleculaire et Cellulaire, Unité Mixte de Recherche 49, Institut National de la Recherche Agronomique LA 913, Ecole Normale Supérieure Lyon, 46, Allee d’Italie, 69364 Lyon Cedex 07, France.
↵ ‖ To whom reprint requests should be addressed at: Massachusetts General Hospital Cancer Center, Mailcode 149-7330, Building 149, 13th Street, Charlestown, MA 02129. e-mail: harlow{at}helix.mgh.harvard.edu.
Ed Harlow
ABBREVIATIONS:

MAP,

mitogen-activated protein;

JNK,

Jun kinase;

ERK,

extracellular signal-regulated kinase;

ICE,

interleukin 1β-converting enzyme;

TNF,

tumor necrosis factor;

NGF,

nerve growth factor;

CMV,

cytomegalovirus;

Z-VAD-fmk,

N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone