Tissue transglutaminase is a caspase substrate during apoptosis. Cleavage causes loss of transamidating function and is a biochemical marker of caspase 3 activation
Tissue transglutaminase is a caspase substrate during apoptosis. Cleavage causes loss of transamidating function and is a biochemical marker of caspase 3 activation
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DOI：
10.1038/sj.cdd.4400573
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发表时间：
1999-10-01
影响因子：
12.4
通讯作者：
Cosulich, E
中科院分区：
文献类型：
--
作者：
Fabbi, M;Marimpietri, D;Cosulich, E
组织转谷氨酰胺酶（tTG）是一种Ca 2+依赖性交联酶，通过不可逆地组装蛋白质支架来参与细胞凋亡机制，从而防止细胞内成分的泄漏。在本研究中，单链抗体片段（scFv）检测tTG。我们证明，TG/F8单链抗体，从相展示文库中选择的人V-基因片段通过结合到豚鼠肝tTG，可以与人tTG在Western blot和免疫组织化学反应。通过纯化蛋白质的质谱分析验证了TG/F8对人胸腺细胞中tTG的特异性检测。此外，我们表明，在淋巴细胞中的tTG是裂解的caspase 3在晚期阶段的凋亡性死亡，伴随着DNA片段化，这种裂解导致交联功能的丧失。我们建议tTG裂解作为一个有价值的生化标志物的半胱天冬酶3激活在晚期执行阶段的细胞凋亡。
Tissue transglutaminase (tTG) is a Ca2+-dependent crosslinking enzyme that participates in the apoptotic machinery by irreversibly assembling a protein scaffold that prevents the leakage of intracellular components. In the present study a single-chain antibody fragment (scFv) detecting tTG is described. We demonstrate that TG/F8 scFv, selected from a phase display library of human V-gene segments by binding to guinea-pig liver tTG, can react with human tTG both in Western blot and in immunohistochemistry. The specific detection of tTG by TG/F8 in human thymocytes is verified by mass spectrometric analysis of the purified protein. Furthermore, we demonstrate that in lymphoid cells tTG is cleaved by caspase 3 during the late phase of apoptotic death, concomitant to DNA fragmentation, and that such cleavage causes loss of cross-linking function. We propose tTG cleavage as a valuable biochemical marker of caspase 3 activation during the late execution phase of apoptosis.