p41 as a possible marker for cell death is generated by caspase cleavage of p42/SETbeta in irradiated MOLT-4 cells.
p41 as a possible marker for cell death is generated by caspase cleavage of p42/SETbeta in irradiated MOLT-4 cells.
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p41 作为细胞死亡的可能标志物，是通过在受辐射的 MOLT-4 细胞中 p42/SETbeta 的 caspase 裂解而产生的。
DOI：
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
K. Sakai
中科院分区：
文献类型：
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作者：
A. Morita;N. Suzuki;Y. Matsumoto;K. Hirano;A. Enomoto;J. Zhu;K. Sakai
我们之前报道过，x照射的MOLT-4细胞在快速死亡过程中，通过二维聚丙烯酰胺凝胶电泳（2-D PAGE）检测到一种名为p41的新蛋白，这种蛋白与剂量和时间相关。一种针对p41部分肽的抗体AM-1意外地染色了p41和p42两个点。部分肽的氨基酸序列分析显示p41与推定的致癌基因set具有同源性。本研究通过对p41和p42的n端氨基酸测序，以及新制备的针对不同部分肽序列的多克隆抗体，发现p41是p42的n端截断形式，p42被鉴定为SETbeta。裂解位点位于p42的SNHD 18的羧基端。caspase特异性抑制剂Ac-DEVD-CHO可抑制辐射诱导的p42切割和凋亡细胞死亡，而Ac-YVAD-CHO则不起作用。进一步用重组p42和辐照细胞提取物或重组caspase进行体外裂解实验，发现p42裂解成p41是由caspase(s)催化的，主要是caspase-7。其中一种新提出的抗体AM-4，对p41或p42的切割位点特异，被发现可以用1-D PAGE代替费力的2-D PAGE简单地检测p41。P41可能是凋亡细胞死亡的标志。
We have reported previously that X-irradiated MOLT-4 cells during their rapid cell death exhibited dose and time dependently a new protein named p41 detected by two-dimensional polyacrylamide gel electrophoresis (2-D PAGE). An antibody, AM-1, raised against partial peptide of p41 stained two spots, p41 and p42, unexpectedly. Amino acid sequence analysis of partial peptides showed homology between p41 and a putative oncogene, set. In the present study, N-terminal amino acid sequencing of p41 and p42, and polyclonal antibodies newly prepared against different partial peptide sequences revealed that p41 was a N-terminal truncation form of p42, and p42 was identified as SETbeta. The cleavage site was at carboxyl end of SNHD 18 of p42. Radiation-induced p42 cleavage as well as apoptotic cell death was suppressed by a caspase-specific inhibitor Ac-DEVD-CHO but not by Ac-YVAD-CHO. Further in vitro cleavage experiments with recombinant p42 and either irradiated cell extracts or recombinant caspases concluded that the cleavage of p42 into p41 was catalyzed by caspase(s) mainly by caspase-7. One of newly raised antibodies, AM-4, specific to p41 or specific to cleavage site of p42, was found useful enabling simple detection of p41 by 1-D PAGE instead of laborious 2-D PAGE. p41 may serve as a marker of apoptotic cell death.