Essential roles of Atg5 and FADD in autophagic cell death: dissection of autophagic cell death into vacuole formation and cell death.
Autophagic cell death is characterized by the accumulation of vacuoles in physiological and pathological conditions. However, its molecular event is unknown. Here, we show that Atg5, which is known to function in autophagy, contributes to autophagic cell death by interacting with Fas-associated protein with death domain (FADD). Down-regulation of Atg5 expression in HeLa cells suppresses cell death and vacuole formation induced by IFN-gamma. Inversely, ectopic expression of Atg5 using adenoviral delivery induces autophagic cell death. Deletion mapping analysis indicates that procell death activity resides in the middle and C-terminal region of Atg5. Cells harboring the accumulated vacuoles triggered by IFN-gamma or Atg5 expression become dead, and vacuole formation precedes cell death. 3-Methyladenine or expression of Atg5(K130R) mutant blocks both cell death and vacuole formation triggered by IFN-gamma, whereas benzyloxycarbonyl-VAD-fluoromethyl ketone (Z-VAD-fmk) inhibits only cell death but not vacuole formation. Atg5 interacts with FADD via death domain in vitro and in vivo, and the Atg5-mediated cell death, but not vacuole formation, is blocked in FADD-deficient cells. These results suggest that Atg5 plays a crucial role in IFN-gamma-induced autophagic cell death by interacting with FADD.
Pyo
Jong-Ok
JO
Department of Life Science, Gwangju Institute of Science and Technology, Gwangju 500-712, Korea.
Jang
Mi-Hee
MH
Kwon
Yun-Kyung
YK
Lee
Ho-June
HJ
Jun
Joon-Il
JI
Woo
Ha-Na
HN
Cho
Dong-Hyung
DH
Choi
Boyoun
B
Lee
Heuiran
H
Kim
Joo-Hang
JH
Mizushima
Noboru
N
Oshumi
Yoshinori
Y
Jung
Yong-Keun
YK
D048868:Adaptor Proteins, Signal Transducing / Q000172:deficiency / Q000502:physiology*; D000225:Adenine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D001343:Autophagy / Q000502:physiology*; D000071187:Autophagy-Related Protein 5; D001665:Binding Sites; D016923:Cell Death / Q000187:drug effects / Q000502:physiology*; D002460:Cell Line; D053200:Fas-Associated Death Domain Protein; D017353:Gene Deletion; D015870:Gene Expression; D006367:HeLa Cells; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D008869:Microtubule-Associated Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D016296:Mutagenesis; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D012441:Saccharomyces cerevisiae; D014162:Transfection; D020798:Two-Hybrid System Techniques; D014617:Vacuoles / Q000187:drug effects / Q000502:physiology*
C502778:ATG5 protein, human; D048868:Adaptor Proteins, Signal Transducing; D000590:Amino Acid Chloromethyl Ketones; D000071187:Autophagy-Related Protein 5; C505533:FADD protein, human; D053200:Fas-Associated Death Domain Protein; D008869:Microtubule-Associated Proteins; D016376:Oligonucleotides, Antisense; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; C025946:3-methyladenine; D007371:Interferon-gamma; D000225:Adenine