کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1938299 | 1536792 | 2006 | 6 صفحه PDF | دانلود رایگان |
If not fertilized, synchronous apoptosis is induced in starfish eggs at ∼11 h after stimulation with the hormone, 1-methyladenine. In this study, a membrane-impermeant substrate of caspase-3, acetyl-Asp-Glu-Val-Asp-coumarylamido-4-methanesulfonic acid (Ac-DEVD-CAMS), was synthesized and microinjected into a starfish egg. Caspase-3 activity in unfertilized egg was detected ∼30 min before blebbing by quantifying the accumulation rate of a membrane-impermeant, fluorogenic product, 7-aminocoumarin-4-methanesulfonic acid (ACMS), using a photomultiplier mounted on a fluorescence microscope. When active recombinant human caspase-3 was microinjected into an egg at 3 h after 1-methyladenine treatment, the injected caspase-3 activity decreased and disappeared within 2 h. This decrease is probably due to proteasome-dependent degradation of the enzyme, since the injected caspase-3 was degraded and a proteasome inhibitor blocked its degradation. In contrast, in aged eggs at ∼10 h after 1-methyladenine treatment, no degradation of the injected caspase-3 was observed, suggesting that endogenous caspase-3 may stabilize at this point, therefore, inducing apoptosis.
Journal: Biochemical and Biophysical Research Communications - Volume 350, Issue 4, 1 December 2006, Pages 878–883