title: Overexpression of the truncated form of Livin reveals a complex interaction with caspase-3.
abstract: Disruption in apoptosis are involved in cancer development and progression. Livin-β, has been identified as a critical modulator for cell death in several tumor cell lines. It was demonstrated that a truncated fragment of Livin-β (tLivin) without its N-terminal 52 amino acids is produced in cells through protein cleavage. However, the biological consequence of the cleavage remains largely ignored. In the present study, we report that tLivin exerted a pro-apoptotic effect on cells. The subcellular localization of tLivin was mainly restricted to the cytoplasm. To explore the underlying mechanism, we observed an elevated caspase-3 activity which may account for the apoptosis. Furthermore, we observed that tLivin was further cleaved into a smaller fragment in cells. This second cleavage was possibly related to activated caspase-3. The resulted C-terminal fragment (livC) was an anti-apoptotic factor. Our study may help to deepen our understanding of the role of Livin in the regulation of cell death.
authors.affiliation: Division of Thoracic Cancer, West China Hospital, State Key Laboratory of Biotherapy, Sichuan University, Chengdu 610041, P.R. China.
authors.forename: Gui-Hong
authors.initials: GH
authors.lastname: Liu
authors.forename: Chun
authors.initials: C
authors.lastname: Wang
authors.forename: Zhen-Yu
authors.initials: ZY
authors.lastname: Ding
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism*; D000970:Antineoplastic Agents / Q000494:pharmacology; D017209:Apoptosis / Q000235:genetics*; D053148:Caspase 3 / Q000378:metabolism*; D045744:Cell Line, Tumor / Q000187:drug effects; D002945:Cisplatin / Q000494:pharmacology; D003593:Cytoplasm / Q000378:metabolism; D004789:Enzyme Activation; D057809:HEK293 Cells; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins / Q000235:genetics / Q000378:metabolism*; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D000970:Antineoplastic Agents; C419866:BIRC7 protein, human; D051034:Inhibitor of Apoptosis Proteins; D009363:Neoplasm Proteins; D011994:Recombinant Proteins; D053148:Caspase 3; D002945:Cisplatin