頁籤選單縮合
題 名 | Proteolytic Cleavage and Activation of PAK2 during UV Irradiation-Induced Apoptosis in A431 Cells |
---|---|
作 者 | Tang,Tswen-kei; Chang,Wen-chang; Chan,Wen-hsiung; Yang,Shiaw-der; Ni,Mei-hui; Yu,Jau-song; | 書刊名 | 中央研究院生物化學研究所論文集 |
卷 期 | 24 1998[民87.] |
頁 次 | 頁9-21 |
分類號 | 361.8 |
關鍵詞 | UV irradiation; PAK2; Apoptosis; CPP32/caspase-3; A431 cells; |
語 文 | 英文(English) |
英文摘要 | Exposure of mammalian ceils to ultraviolet (UV) light elicits a cellular response and can also lead to apoptotic cell death. In this report, we show that a 36-kDa myelin basic protein (MBP) kinase detected by an in-gel kinase assay can be dramatically activated during the early stages of UV irradiation-triggered apoptosis of A431 cells. Immunoblot analysis revealed that this 36-kDa MBP kinase could be recognized by an antibody against the C-terminal regions of a family of p21 □□ /□□ -activated kinases (PAKs). By using this antibody and a PAK2-specific antibody against the N-terminal region of PAK2 as studying tools, we further demonstrated that UV irradiation caused cleavage of PAK2 to generate a 36-kDa C-terminal catalytic fragment and a 30-kDa N-terminal fragment in A431 cells. The appearance of the 36-kDa C-terminal catalytic fragment of PAK2 matched exactly with the activation of the 36-kDa MBP kinase in A431 cells upon UV irradiation. In addition, UV irradiation also led to activation of CPP32/caspase-3, but not ICH-1L/ caspase-2 and ICE/caspase-I, in A431 cells and the kinetics of activation of CPP32/caspase-3 appeared to correlate well with that of DNA fragmentation and of cleavage/activation of PAK2, respectively. Moreover, blockage of activation of CCP32/caspase-3 by pretreating the cells with two specific tetrapeptidic inhibitors for caspases (Ac-DEVD-cho and Ac-YVAD-cmk) could significantly attenuate the extent of cleavage/activation of PAK2 induced by UV irradiation. Collectively, the results demonstrate that cleavage and activation of PAK2 can be induced during the early stages of UV irradiation-triggered apoptosis and indicate the involvement of CPP32/caspase-3 in this process. |
本系統中英文摘要資訊取自各篇刊載內容。