TY  - JOUR
AU  - Sutton, VR
AU  - Davis, JE
AU  - Cancilla, M
AU  - Johnstone, RW
AU  - Ruefli, AA
AU  - Sedelies, K
AU  - Browne, KA
AU  - Trapani, JA
Y2  - 2020/12/22
Y1  - 2000/11/20
SN  - 0022-1007
UR  - http://hdl.handle.net/11343/257747
AB  - The essential upstream steps in granzyme B-mediated apoptosis remain undefined. Herein, we show that granzyme B triggers the mitochondrial apoptotic pathway through direct cleavage of Bid; however, cleavage of procaspases was stalled when mitochondrial disruption was blocked by Bcl-2. The sensitivity of granzyme B-resistant Bcl-2-overexpressing FDC-P1 cells was restored by coexpression of wild-type Bid, or Bid with a mutation of its caspase-8 cleavage site, and both types of Bid were cleaved. However, Bid with a mutated granzyme B cleavage site remained intact and did not restore apoptosis. Bid with a mutation preventing its interaction with Bcl-2 was cleaved but also failed to restore apoptosis. Rapid Bid cleavage by granzyme B (<2 min) was not delayed by Bcl-2 overexpression. These results clearly placed Bid cleavage upstream of mitochondrial Bcl-2. In granzyme B-treated Jurkat cells, endogenous Bid cleavage and loss of mitochondrial membrane depolarization occurred despite caspase inactivation with z-Val-Ala-Asp-fluoromethylketone or Asp-Glu-Val-Asp-fluoromethylketone. Initial partial processing of procaspase-3 and -8 was observed irrespective of Bcl-2 overexpression; however, later processing was completely abolished by Bcl-2. Overall, our results indicate that mitochondrial perturbation by Bid is necessary to achieve a lethal threshold of caspase activity and cell death due to granzyme B.
LA  - English
PB  - ROCKEFELLER UNIV PRESS
T1  - Initiation of apoptosis by granzyme B requires direct cleavage of Bid, but not direct granzyme B-mediated caspase activation
DO  - 10.1084/jem.192.10.1403
IS  - Journal of Experimental Medicine
VL  - 192
IS  - 10
SP  - 1403-1413
L1  - /bitstream/handle/11343/257747/PMC2193191.pdf?sequence=1&isAllowed=y
ER  -