Yao S L, McKenna K A, Sharkis S J, Bedi A
The Johns Hopkins Oncology Center, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA.
Cancer Res. 1996 Oct 15;56(20):4551-5.
The induction of apoptosis by the Fas/APO-1 receptor is important for T-cell-mediated cytotoxicity and down-regulation of immune responses. Binding of Fas ligand to the Fas/APO-1 receptor transduces an apoptotic signal that requires activation of interleukin 1beta-converting enzyme (ICE) and CPP32beta, members of a family of cysteine proteases that are evolutionarily conserved determinants of cell death. We report here that Fas/APO-1-triggered apoptosis involves ICE-mediated activation of p34cdc2 kinase. Ligation of the Fas receptor resulted in the rapid stimulation of ICE proteolytic activity and activation of p34cdc2 kinase. Specific tetrapeptide inhibitors of ICE (Acetyl-Tyr-Val-Ala-Asp-chloromethylketone) or CPP32beta (Acetyl-Asp-Glu-Val-Asp-aldehyde) prevented the anti-Fas antibody-mediated activation of p34cdc2 and inhibited apoptosis. Inhibition of p34cdc2 activity by transient overexpression of a dominant-negative cdc2 construct or human WEE1 kinase inhibited Fas-mediated apoptosis. These results suggest that activation of p34cdc2 kinase is a critical determinant of cell death mediated by Fas and ICE family proteases.
Fas/APO-1受体诱导细胞凋亡对于T细胞介导的细胞毒性和免疫反应的下调很重要。Fas配体与Fas/APO-1受体的结合转导了一个凋亡信号，该信号需要激活白细胞介素1β转换酶（ICE）和CPP32β，它们是半胱氨酸蛋白酶家族的成员，是细胞死亡在进化上保守的决定因素。我们在此报告，Fas/APO-1触发的细胞凋亡涉及ICE介导的p34cdc2激酶激活。Fas受体的连接导致ICE蛋白水解活性的快速刺激和p34cdc2激酶的激活。ICE的特异性四肽抑制剂（乙酰基-酪氨酸-缬氨酸-丙氨酸-天冬氨酸-氯甲基酮）或CPP32β（乙酰基-天冬氨酸-谷氨酸-缬氨酸-天冬氨酸-醛）可阻止抗Fas抗体介导的p34cdc2激活并抑制细胞凋亡。通过瞬时过表达显性负性cdc2构建体或人WEE1激酶抑制p34cdc2活性可抑制Fas介导的细胞凋亡。这些结果表明，p34cdc2激酶的激活是Fas和ICE家族蛋白酶介导的细胞死亡的关键决定因素。
