Phosphorylation of FADD at serine 194 by CKIalpha regulates its nonapoptotic activities.
FADD is essential for death receptor (DR)-induced apoptosis. However, it is also critical for cell cycle progression and proliferation, activities that are regulated by phosphorylation of its C-terminal Ser194, which has also been implicated in sensitizing cancer cells to chemotherapeutic drugs and in regulating FADD's intracellular localization. We now demonstrate that casein kinase Ialpha (CKIalpha) phosphorylates FADD at Ser194 both in vitro and in vivo. FADD-CKIalpha association regulates the subcellular localization of FADD, and phosphorylated FADD was found to colocalize with CKIalpha on the spindle poles in metaphase. Inhibition of CKIalpha diminished FADD phosphorylation, prevented the ability of Taxol to arrest cells in mitosis, and blocked mitogen-induced proliferation of mouse splenocytes. In contrast, a low level of cycling splenocytes from mice expressing FADD with a mutated phosphorylation site was insensitive to CKI inhibition. These data suggest that phosphorylation of FADD by CKI is a crucial event during mitosis.
Alappat
Elizabeth C
EC
The Ben May Institute for Cancer Research, The University of Chicago, Chicago, Illinois 60637, USA.
Feig
Christine
C
Boyerinas
Benjamin
B
Volkland
Jörg
J
Samuels
Martin
M
Murmann
Andrea E
AE
Thorburn
Andrew
A
Kidd
Vincent J
VJ
Slaughter
Clive A
CA
Osborn
Stephanie L
SL
Winoto
Astar
A
Tang
Wei-Jen
WJ
Peter
Marcus E
ME
D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis; D001665:Binding Sites / Q000235:genetics; D048128:Casein Kinase Ialpha / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D002453:Cell Cycle / Q000187:drug effects / Q000502:physiology; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D003208:Concanavalin A / Q000494:pharmacology; D003600:Cytosol / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D053200:Fas-Associated Death Domain Protein; D006367:HeLa Cells; D006801:Humans; D007546:Isoquinolines / Q000494:pharmacology; D019169:Jurkat Cells; D008213:Lymphocyte Activation; D051379:Mice; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D008938:Mitosis / Q000187:drug effects / Q000502:physiology; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D017239:Paclitaxel / Q000494:pharmacology; D010766:Phosphorylation; D011485:Protein Binding; D021381:Protein Transport / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D012694:Serine / Q000378:metabolism*; D008941:Spindle Apparatus / Q000378:metabolism; D013601:T-Lymphocytes / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014162:Transfection
D048868:Adaptor Proteins, Signal Transducing; D004791:Enzyme Inhibitors; C505533:FADD protein, human; C505534:Fadd protein, mouse; D053200:Fas-Associated Death Domain Protein; D007546:Isoquinolines; D034741:RNA, Small Interfering; D003208:Concanavalin A; C058815:N-(2-aminoethyl)-5-chloroisoquinoline-8-sulfonamide; D012694:Serine; D048128:Casein Kinase Ialpha; D013755:Tetradecanoylphorbol Acetate; D017239:Paclitaxel