Journal article
The Apoptosis Inhibitor ARC Undergoes Ubiquitin-Proteasomal-mediated Degradation in Response to Death Stimuli
The Journal of biological chemistry, Vol.282(8), pp.5522-5528
02/23/2007
DOI: 10.1074/jbc.M609186200
PMID: 17142452
Abstract
Efficient induction of apoptosis requires not only the activation of death-promoting proteins but also the inactivation of inhibitors of cell death. ARC (apoptosis repressor with caspase recruitment domain) is an endogenous inhibitor of apoptosis that antagonizes both central apoptosis pathways. Despite its potent inhibition of cell death, cells that express abundant ARC eventually succumb. A possible explanation is that ARC protein levels decrease dramatically in response to death stimuli. The mechanisms that mediate decreases in ARC protein levels during apoptosis and whether these decreases initiate the subsequent cell death are not known. Here we show that endogenous ARC protein levels decrease in response to death stimuli in a variety of cell contexts as well as in a model of myocardial ischemia-reperfusion in intact mice. Decreases in ARC protein levels are not explained by alterations in the abundance of ARC transcripts. Rather, pulse-chase experiments show that decreases in steady state ARC protein levels during apoptosis result from marked destabilization of ARC protein. ARC protein destabilization, in turn, is mediated by the ubiquitin-proteasomal pathway, as mutation of ARC ubiquitin acceptor residues stabilizes ARC protein and preserves its steady state levels during apoptosis. In addition, this degradation-resistant ARC mutant exhibits improved cytoprotection. We conclude that decreases in ARC protein levels in response to death stimuli are mediated by increased ARC protein degradation via the ubiquitin-proteasomal pathway. Moreover, these data demonstrate that decreases in ARC protein levels are a trigger, and not merely a consequence, of the ensuing cell death.
Details
- Title: Subtitle
- The Apoptosis Inhibitor ARC Undergoes Ubiquitin-Proteasomal-mediated Degradation in Response to Death Stimuli
- Creators
- Young-Jae Nam - Department of MedicineKartik Mani - Department of MedicineLily Wu - Department of MedicineChang-Fu Peng - Department of MedicineJohn W. Calvert - Department of MedicineRoger S.-Y. Foo - Department of MedicineBarath Krishnamurthy - Department of MedicineWenfeng Miao - Department of MedicineAnthony W. Ashton - Department of MedicineDavid J. Lefer - Department of MedicineRichard N. Kitsis - Albert Einstein College of Medicine
- Resource Type
- Journal article
- Publication Details
- The Journal of biological chemistry, Vol.282(8), pp.5522-5528
- Publisher
- Elsevier Inc; ROCKVILLE
- DOI
- 10.1074/jbc.M609186200
- PMID
- 17142452
- ISSN
- 0021-9258
- eISSN
- 1083-351X
- Grant note
- NHLBI NIH HHS: R01HL61550, R01HL80607, R01HL60665 NIDDK NIH HHS: P60DK020541
- Language
- English
- Date published
- 02/23/2007
- Academic Unit
- Internal Medicine
- Record Identifier
- 9984695835302771
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