Bax cleavage is mediated by calpain during drug-induced apoptosis.

Wood, D E; Thomas, A; Devi, L A; Berman, Y; Beavis, R C; Reed, J C; Newcomb, E W

Wood, D E; Thomas, A; Devi, L A; Berman, Y; Beavis, R C; Reed, J C; Newcomb, E W.

Afiliación

Wood DE; Department of Pathology, New York University Medical Center and Kaplan Comprehensive Cancer Center, New York 10016, USA.

Oncogene ; 17(9): 1069-78, 1998 Sep 03.

Article en En | MEDLINE | ID: mdl-9764817

RESUMEN

The anti-apoptotic molecule Bcl-2 is located in the mitochondrial and endoplasmic reticulum membranes as well as the nuclear envelope. Although its location has not been as rigorously defined, the pro-apoptotic molecule Bax appears to be mainly a cytosolic protein which translocates to the mitochondria upon induction of apoptosis. Here we identify a protease activity in mitochondria-enriched membrane fractions from HL-60 cells capable of cleaving Bax which is absent from the cytosolic fraction. Bax protease activity is blocked in vitro by cysteine protease inhibitors including E-64 which distinguishes it from all known caspases and granzyme B, both of which are involved in apoptosis. Protease activity is also blocked by inhibitors against the calcium-activated neutral cysteine endopeptidase calpain. Partial purification of the Bax protease activity from HL-60 cell membrane fractions by column chromatography revealed that a calpain-like activity was the protease responsible for Bax cleavage. In addition, purified calpain enzymes cleaved Bax in a calcium-dependent manner. Pretreatment of HL-60 cells with the specific calpain inhibitor calpeptin effectively blocked both drug-induced Bax cleavage and calpain activation, but not PARP cleavage or cell death. These results suggest that calpains and caspases are activated during drug-induced apoptosis and that calpains, along with caspases, may be involved in modulating cell death by acting selectively on cellular substrates.

Asunto(s)

Apoptosis/efectos de los fármacos; Calpaína/farmacología; Inhibidores de Cisteína Proteinasa/farmacología; Proteínas Proto-Oncogénicas c-bcl-2; Proteínas Proto-Oncogénicas/metabolismo; Alanina/genética; Secuencia de Aminoácidos; Ácido Aspártico/genética; Sitios de Unión/efectos de los fármacos; Sitios de Unión/genética; Calpaína/antagonistas & inhibidores; Calpaína/aislamiento & purificación; Camptotecina/análogos & derivados; Camptotecina/antagonistas & inhibidores; Camptotecina/farmacología; Muerte Celular/efectos de los fármacos; Extractos Celulares/química; Membrana Celular/efectos de los fármacos; Membrana Celular/enzimología; Dipéptidos/farmacología; Células HL-60/efectos de los fármacos; Células HL-60/enzimología; Células HL-60/ultraestructura; Humanos; Hidrólisis/efectos de los fármacos; Leucina/análogos & derivados; Leucina/farmacología; Datos de Secuencia Molecular; Mutación/genética; Poli(ADP-Ribosa) Polimerasas/efectos de los fármacos; Poli(ADP-Ribosa) Polimerasas/metabolismo; Proteínas Proto-Oncogénicas/química; Proteínas Proto-Oncogénicas/genética; Especificidad por Sustrato; Proteína X Asociada a bcl-2

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Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Calpaína / Inhibidores de Cisteína Proteinasa / Proteínas Proto-Oncogénicas / Apoptosis / Proteínas Proto-Oncogénicas c-bcl-2 Límite: Humans Idioma: En Revista: Oncogene Asunto de la revista: BIOLOGIA MOLECULAR / NEOPLASIAS Año: 1998 Tipo del documento: Article País de afiliación: Estados Unidos Pais de publicación: Reino Unido

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