Source:http://linkedlifedata.com/resource/pubmed/id/12624108
Switch to
Predicate | Object |
---|---|
rdf:type | |
lifeskim:mentions | |
pubmed:issue |
19
|
pubmed:dateCreated |
2003-5-5
|
pubmed:abstractText |
Bcl-2 family proteins are important regulators of apoptosis. They can be pro-apoptotic (e.g. Bid, Bax, and Bak) or anti-apoptotic (e.g. Bcl-2 and Bcl-x(L)). The current study examined Bid-induced apoptosis and its inhibition by Bcl-2. Transfection of Bid led to apoptosis in HeLa cells. In these cells, Bid was processed into active forms of truncated Bid or tBid. Following processing, tBid translocated to the membrane-bound organellar fraction. Bcl-2 co-transfection inhibited Bid-induced apoptosis but did not prevent Bid processing or tBid translocation. On the other hand, Bcl-2 blocked the release of mitochondrial cytochrome c in Bid-transfected cells, suggesting actions at the mitochondrial level. Alkaline treatment stripped off tBid from the membrane-bound organellar fraction of Bid plus Bcl-2-co-transfected cells, but not from cells transfected with only Bid, suggesting inhibition of tBid insertion into mitochondrial membranes by Bcl-2. Bcl-2 also prevented Bid-induced Bax translocation from cytosol to the membrane-bound organellar fraction. Finally, Bcl-2 diminished Bid-induced oligomerization of Bax and Bak within the membrane-bound organellar fraction, shown by cross-linking experiments. In conclusion, Bcl-2 inhibited Bid-induced apoptosis at the mitochondrial level by blocking cytochrome c release, without suppressing Bid processing or activation. Critical steps blocked by Bcl-2 included tBid insertion, Bax translocation, and Bax/Bak oligomerization in the mitochondrial membranes.
|
pubmed:grant | |
pubmed:language |
eng
|
pubmed:journal | |
pubmed:citationSubset |
IM
|
pubmed:chemical | |
pubmed:status |
MEDLINE
|
pubmed:month |
May
|
pubmed:issn |
0021-9258
|
pubmed:author | |
pubmed:issnType |
Print
|
pubmed:day |
9
|
pubmed:volume |
278
|
pubmed:owner |
NLM
|
pubmed:authorsComplete |
Y
|
pubmed:pagination |
16992-9
|
pubmed:dateRevised |
2007-11-14
|
pubmed:meshHeading |
pubmed-meshheading:12624108-Apoptosis,
pubmed-meshheading:12624108-BH3 Interacting Domain Death Agonist Protein,
pubmed-meshheading:12624108-Carrier Proteins,
pubmed-meshheading:12624108-Dimerization,
pubmed-meshheading:12624108-Gene Expression Regulation,
pubmed-meshheading:12624108-Genes, bcl-2,
pubmed-meshheading:12624108-HeLa Cells,
pubmed-meshheading:12624108-Humans,
pubmed-meshheading:12624108-Mitochondria,
pubmed-meshheading:12624108-Protein Transport
|
pubmed:year |
2003
|
pubmed:articleTitle |
Inhibition of Bid-induced apoptosis by Bcl-2. tBid insertion, Bax translocation, and Bax/Bak oligomerization suppressed.
|
pubmed:affiliation |
Department of Anatomy and Cell Biology, Medical College of Georgia, Augusta, Georgia 30912, USA.
|
pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
|