Abstract
We have recently characterized a novel 16-kDa Bax-associated protein. In this study, we investigate the regulation of this protein's expression during in vitro induction of apoptosis in mature splenic B cells. A panel of biochemically distinct apoptotic stimuli induced the dramatic down-modulation of the 16-kDa protein in B cells; this down-modulation was rapid, and did not require DNA fragmentation. Reciprocally, stimuli that induced protection from apoptosis prevented down-modulation of the 16-kDa protein. These regulatory effects were specific, since Bcl-2 and Bax protein levels were not similarly modulated. Stimuli that reduce expression of the 16-kDa protein may therefore act indirectly to increase the proapoptotic activity of Bax, perhaps by altering Bax binding to other cellular proteins.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Animals
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Apoptosis / drug effects
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Apoptosis / immunology*
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B-Lymphocytes / cytology
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B-Lymphocytes / immunology
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B-Lymphocytes / metabolism*
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Carrier Proteins / biosynthesis*
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Carrier Proteins / chemistry*
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Carrier Proteins / immunology
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Carrier Proteins / physiology
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Cell Differentiation / immunology
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Down-Regulation / immunology*
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Female
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Interleukin-4 / pharmacology
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Mice
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Mice, Inbred C57BL
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Proto-Oncogene Proteins / metabolism*
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Proto-Oncogene Proteins c-bcl-2 / metabolism*
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Proto-Oncogene Proteins c-bcl-2 / physiology
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Time Factors
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bcl-2-Associated X Protein
Substances
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Bax protein, mouse
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Bax-associated protein P16, mouse
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Carrier Proteins
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Proto-Oncogene Proteins
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Proto-Oncogene Proteins c-bcl-2
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bcl-2-Associated X Protein
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Interleukin-4