Stoichiometry and regulation network of Bcl-2 family complexes quantified by live-cell FRET assay
The stoichiometry and affinity of Bcl-2 family complexes are essential information for understanding how their interactome network is orchestrated to regulate mitochondrial permeabilization and apoptosis. Based on over-expression model system, FRET analysis was used to quantify the protein–protein i...
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Published in | Cellular and molecular life sciences : CMLS Vol. 77; no. 12; pp. 2387 - 2406 |
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Main Authors | , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Cham
Springer International Publishing
01.06.2020
Springer Nature B.V |
Subjects | |
Online Access | Get full text |
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Summary: | The stoichiometry and affinity of Bcl-2 family complexes are essential information for understanding how their interactome network is orchestrated to regulate mitochondrial permeabilization and apoptosis. Based on over-expression model system, FRET analysis was used to quantify the protein–protein interactions among Bax, Bcl-xL, Bad and tBid in healthy and apoptotic cells. Our data indicate that the stoichiometry and affinity of Bcl-2 complexes are dependent on their membrane environment. Bcl-xL, Bad and tBid can form hetero-trimers in mitochondria. Bcl-xL binds preferentially to Bad, then to tBid and Bax in mitochondria, whilst Bcl-xL displays higher affinity to Bad or tBid than to itself. Strikingly, Bax can bind to Bcl-xL in cytosol. In cytosol of apoptotic cells, Bcl-xL associates with Bax to form hetero-trimer with 1:2 stoichiometry, while Bcl-xL associates with Bad to form hetero-trimer with 2:1 stoichiometry and Bcl-xL associates with tBid to form hetero-dimer. In mitochondria, Bcl-xL associates with Bax/Bad to form hetero-dimer in healthy cells, while Bcl-xL associates with Bad to form hetero-tetramer with 3:1 stoichiometry in apoptotic cells. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 1420-682X 1420-9071 |
DOI: | 10.1007/s00018-019-03286-z |