Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
28
pubmed:dateCreated
2000-8-16
pubmed:abstractText
Under basal conditions, the proapoptotic protein Bid is a long-lived protein. Pro-apoptotic stimuli such as tumor necrosis factor-alpha (TNFalpha) or Fas induce its caspase-8-mediated cleavage into two fragments. The COOH-terminal cleavage fragment of Bid (tBid) becomes localized to mitochondrial membranes and triggers the release of cytochrome c. Here we show that tBid is ubiquitinated and subsequently degraded by the 26 S proteasome. Degradation of tBid is significantly inhibited by the proteasome inhibitors MG-132 and lactacystin. In contrast, caspase-specific or lysosomal inhibitors do not affect tBid stability. Furthermore, mutation of the putative ubiquitin acceptor sites within tBid results in a stabilized protein as assessed by pulse-chase analysis. To address whether tBid degradation might be regulated by interaction with other Bcl-2-like proteins, cotransfection studies were performed. However, neither the presence of proapoptotic Bax nor antiapoptotic Bcl-2 or Bcl-XL affected tBid degradation. Finally, we determined the functional role of tBid degradation. Overexpression of stabilized tBid proteins significantly enhanced cytochrome c release and subsequent apoptosis induction approximately 2-fold compared with wild type tBid. Similarly, tBid-induced apoptosis was considerably amplified by inhibition of tBid degradation using the proteasome-specific inhibitor MG-132. Thus, proteasomal degradation of tBid limits the extent of apoptosis in living cells.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/BCL2L1 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/BH3 Interacting Domain Death..., http://linkedlifedata.com/resource/pubmed/chemical/BID protein, human, http://linkedlifedata.com/resource/pubmed/chemical/Carrier Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Cysteine Proteinase Inhibitors, http://linkedlifedata.com/resource/pubmed/chemical/Leupeptins, http://linkedlifedata.com/resource/pubmed/chemical/Proto-Oncogene Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Proto-Oncogene Proteins c-bcl-2, http://linkedlifedata.com/resource/pubmed/chemical/Recombinant Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Ubiquitins, http://linkedlifedata.com/resource/pubmed/chemical/bcl-X Protein, http://linkedlifedata.com/resource/pubmed/chemical/benzyloxycarbonylleucyl-leucyl-leuci...
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
14
pubmed:volume
275
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
21648-52
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:10801801-Animals, pubmed-meshheading:10801801-Apoptosis, pubmed-meshheading:10801801-BH3 Interacting Domain Death Agonist Protein, pubmed-meshheading:10801801-COS Cells, pubmed-meshheading:10801801-Carrier Proteins, pubmed-meshheading:10801801-Cloning, Molecular, pubmed-meshheading:10801801-Cysteine Proteinase Inhibitors, pubmed-meshheading:10801801-HeLa Cells, pubmed-meshheading:10801801-Humans, pubmed-meshheading:10801801-Leupeptins, pubmed-meshheading:10801801-Mutagenesis, Site-Directed, pubmed-meshheading:10801801-Proto-Oncogene Proteins, pubmed-meshheading:10801801-Proto-Oncogene Proteins c-bcl-2, pubmed-meshheading:10801801-Recombinant Proteins, pubmed-meshheading:10801801-Restriction Mapping, pubmed-meshheading:10801801-Transfection, pubmed-meshheading:10801801-Ubiquitins, pubmed-meshheading:10801801-bcl-X Protein
pubmed:year
2000
pubmed:articleTitle
Ubiquitin-mediated degradation of the proapoptotic active form of bid. A functional consequence on apoptosis induction.
pubmed:affiliation
Division of Molecular Cardiology, Department of Internal Medicine IV, University of Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't