Apoptosis-linked gene 2 binds to the death domain of Fas and dissociates from Fas during Fas-mediated apoptosis in Jurkat cells.
Apoptosis-linked gene 2 (ALG-2) is a member of the family of Ca(2+)-binding proteins with penta-EF-hand and is essential for the execution of apoptosis by various signals including Fas activation. We studied the regulation of ALG-2 during Fas-mediated apoptosis in Jurkat cells. The 22-kDa ALG-2 protein is cleaved and becomes a 19-kDa protein after Fas activation. The appearance of 19-kDa ALG-2 protein increases for 4 h after treatment with 200 ng/ml of anti-Fas Ab treatment and gradually degrades afterward. Confocal microscopic analysis showed that ALG-2 translocated from the plasma membrane to the cytosol during Fas-mediated apoptosis. Therefore, we examined if ALG-2 interacts with Fas. The protein-protein interaction of ALG-2 with Fas was demonstrated using yeast two-hybrid assays as well as in vitro GST pull-down assay. Endogenous ALG-2 was immunoprecipitated with anti-Fas Ab in Jurkat cells without Fas activation. However, the endogenous ALG-2 was no longer immunoprecipitated with anti-Fas Ab 2 h after anti-Fas Ab treatment. This study, for the first time, presents a direct molecular connection of ALG-2 to apoptosis by its direct interaction with Fas, and enlists ALG-2 as a new member of posttranslationally modified proteins during Fas-mediated apoptotic process.
Jung
Y S
YS
Research Center for Biomedicinal Resources and Division of Life Science, PaiChai University, Taejon, Korea 302-735.
Kim
K S
KS
Kim
K D
KD
Lim
J S
JS
Kim
J W
JW
Kim
E
E
D017209:Apoptosis / Q000502:physiology*; D051017:Apoptosis Regulatory Proteins; D001665:Binding Sites; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D006801:Humans; D019169:Jurkat Cells; D017434:Protein Structure, Tertiary; D015398:Signal Transduction / Q000502:physiology; D019014:fas Receptor / Q000378:metabolism*
D051017:Apoptosis Regulatory Proteins; D002135:Calcium-Binding Proteins; C097753:PDCD6 protein, human; D019014:fas Receptor