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Caspase-3-dependent cleavage of Bcl-2 promotes release of cytochrome c.

Publication ,  Journal Article
Kirsch, DG; Doseff, A; Chau, BN; Lim, DS; de Souza-Pinto, NC; Hansford, R; Kastan, MB; Lazebnik, YA; Hardwick, JM
Published in: J Biol Chem
July 23, 1999

Caspases are cysteine proteases that mediate apoptosis by proteolysis of specific substrates. Although many caspase substrates have been identified, for most substrates the physiologic caspase(s) required for cleavage is unknown. The Bcl-2 protein, which inhibits apoptosis, is cleaved at Asp-34 by caspases during apoptosis and by recombinant caspase-3 in vitro. In the present study, we show that endogenous caspase-3 is a physiologic caspase for Bcl-2. Apoptotic extracts from 293 cells cleave Bcl-2 but not Bax, even though Bax is cleaved to an 18-kDa fragment in SK-NSH cells treated with ionizing radiation. In contrast to Bcl-2, cleavage of Bax was only partially blocked by caspase inhibitors. Inhibitor profiles indicate that Bax may be cleaved by more than one type of noncaspase protease. Immunodepletion of caspase-3 from 293 extracts abolished cleavage of Bcl-2 and caspase-7, whereas immunodepletion of caspase-7 had no effect on Bcl-2 cleavage. Furthermore, MCF-7 cells, which lack caspase-3 expression, do not cleave Bcl-2 following staurosporine-induced cell death. However, transient transfection of caspase-3 into MCF-7 cells restores Bcl-2 cleavage after staurosporine treatment. These results demonstrate that in these models of apoptosis, specific cleavage of Bcl-2 requires activation of caspase-3. When the pro-apoptotic caspase cleavage fragment of Bcl-2 is transfected into baby hamster kidney cells, it localizes to mitochondria and causes the release of cytochrome c into the cytosol. Therefore, caspase-3-dependent cleavage of Bcl-2 appears to promote further caspase activation as part of a positive feedback loop for executing the cell.

Duke Scholars

Published In

J Biol Chem

DOI

ISSN

0021-9258

Publication Date

July 23, 1999

Volume

274

Issue

30

Start / End Page

21155 / 21161

Location

United States

Related Subject Headings

  • Substrate Specificity
  • Proto-Oncogene Proteins c-bcl-2
  • Humans
  • HL-60 Cells
  • Enzyme Activation
  • Cytochrome c Group
  • Cricetinae
  • Caspases
  • Caspase 3
  • Biochemistry & Molecular Biology
 

Citation

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Kirsch, D. G., Doseff, A., Chau, B. N., Lim, D. S., de Souza-Pinto, N. C., Hansford, R., … Hardwick, J. M. (1999). Caspase-3-dependent cleavage of Bcl-2 promotes release of cytochrome c. J Biol Chem, 274(30), 21155–21161. https://doi.org/10.1074/jbc.274.30.21155
Kirsch, D. G., A. Doseff, B. N. Chau, D. S. Lim, N. C. de Souza-Pinto, R. Hansford, M. B. Kastan, Y. A. Lazebnik, and J. M. Hardwick. “Caspase-3-dependent cleavage of Bcl-2 promotes release of cytochrome c.J Biol Chem 274, no. 30 (July 23, 1999): 21155–61. https://doi.org/10.1074/jbc.274.30.21155.
Kirsch DG, Doseff A, Chau BN, Lim DS, de Souza-Pinto NC, Hansford R, et al. Caspase-3-dependent cleavage of Bcl-2 promotes release of cytochrome c. J Biol Chem. 1999 Jul 23;274(30):21155–61.
Kirsch, D. G., et al. “Caspase-3-dependent cleavage of Bcl-2 promotes release of cytochrome c.J Biol Chem, vol. 274, no. 30, July 1999, pp. 21155–61. Pubmed, doi:10.1074/jbc.274.30.21155.
Kirsch DG, Doseff A, Chau BN, Lim DS, de Souza-Pinto NC, Hansford R, Kastan MB, Lazebnik YA, Hardwick JM. Caspase-3-dependent cleavage of Bcl-2 promotes release of cytochrome c. J Biol Chem. 1999 Jul 23;274(30):21155–21161.

Published In

J Biol Chem

DOI

ISSN

0021-9258

Publication Date

July 23, 1999

Volume

274

Issue

30

Start / End Page

21155 / 21161

Location

United States

Related Subject Headings

  • Substrate Specificity
  • Proto-Oncogene Proteins c-bcl-2
  • Humans
  • HL-60 Cells
  • Enzyme Activation
  • Cytochrome c Group
  • Cricetinae
  • Caspases
  • Caspase 3
  • Biochemistry & Molecular Biology