کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
10802278 1055679 2013 14 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Determining the contributions of caspase-2, caspase-8 and effector caspases to intracellular VDVADase activities during apoptosis initiation and execution
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Determining the contributions of caspase-2, caspase-8 and effector caspases to intracellular VDVADase activities during apoptosis initiation and execution
چکیده انگلیسی
Apoptosis signaling crucially depends on caspase activities. Caspase-2 shares features of both initiator and effector caspases. Opinions are divided on whether caspase-2 activity is established during apoptosis initiation or execution in response to DNA damage, death receptor stimulation, or heat shock. So far, approaches towards measuring caspase-2 activity were restricted to analyses in cell homogenates and extracts, yielded inconsistent results, and were often limited in sensitivity, thereby contributing to controversies surrounding the role of caspase-2 during apoptosis. Furthermore, caspases overlap in substrate specificities, and caspase-8 as well as effector caspases may cleave the optimal VDVAD recognition motif as well. We therefore generated a highly sensitive Förster resonance energy transfer (FRET) substrate to determine the relative contribution of these caspases to VDVADase activity non-invasively inside living cells. We observed limited proteolysis of the substrate during apoptosis initiation in response to death receptor stimulation by FasL, TNFα and TRAIL. However, this activity was attributable to caspase-8 rather than caspase-2. Likewise, no caspase-2-specific activity was detected during apoptosis initiation in response to genotoxic stress (cisplatin, 5-FU), microtubule destabilization (vincristine), or heat shock. The contribution of caspase-2 to proteolytic activities during apoptosis execution was insignificant. Since even residual, ectopically introduced caspase-2 activity could readily be detected inside living cells in our measurements, we conclude, in contrast to several previous studies, that caspase-2 activity does not contribute to apoptosis in the scenarios investigated, and that instead caspase-8 and effector caspases are the most significant VDVADases during canonical apoptosis signaling.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biochimica et Biophysica Acta (BBA) - Molecular Cell Research - Volume 1833, Issue 10, October 2013, Pages 2279-2292
نویسندگان
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