title: p31comet-Induced Cell Death Is Mediated by Binding and Inactivation of Mad2.
abstract: Mad2, a key component of the spindle checkpoint, is closely associated with chromosomal instability and poor prognosis in cancer. p31comet is a Mad2-interacting protein that serves as a spindle checkpoint silencer at mitosis. In this study, we showed that p31comet-induced apoptosis and senescence occur via counteraction of Mad2 activity. Upon retroviral transduction of p31comet, the majority of human cancer cell lines tested lost the ability to form colonies in a low-density seeding assay. Cancer cells with p31comet overexpression underwent distinct apoptosis and/or senescence, irrespective of p53 status, confirming the cytotoxicity of p31comet. Interestingly, both cytotoxic and Mad2 binding activities were eliminated upon deletion of the C-terminal 30 amino acids of p31comet. Point mutation or deletion of the region affecting Mad2 binding additionally abolished cytotoxic activity. Consistently, wild-type Mad2 interacting with p31comet, but not its non-binding mutant, inhibited cell death, indicating that the mechanism of p31comet-induced cell death involves Mad2 inactivation. Our results clearly suggest that the regions of p31comet affecting interactions with Mad2, including the C-terminus, are essential for induction of cell death. The finding that p31comet-induced cell death is mediated by interactions with Mad2 that lead to its inactivation is potentially applicable in anticancer therapy.
authors.affiliation: Division of Radiation Cancer Research, Korea Institute of Radiological & Medical Sciences, Seoul 139-706, Korea.
authors.forename: Hyun-Jin
authors.initials: HJ
authors.lastname: Shin
authors.affiliation: Division of Radiation Cancer Research, Korea Institute of Radiological & Medical Sciences, Seoul 139-706, Korea.|Department of Pathology and BK 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, 120-749, Korea.
authors.forename: Eun-Ran
authors.initials: ER
authors.lastname: Park
authors.affiliation: Division of Radiation Cancer Research, Korea Institute of Radiological & Medical Sciences, Seoul 139-706, Korea.
authors.forename: Sun-Hee
authors.initials: SH
authors.lastname: Yun
authors.affiliation: Division of Radiation Cancer Research, Korea Institute of Radiological & Medical Sciences, Seoul 139-706, Korea.
authors.forename: Su-Hyeon
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Division of Radiation Cancer Research, Korea Institute of Radiological & Medical Sciences, Seoul 139-706, Korea.
authors.forename: Won-Hee
authors.initials: WH
authors.lastname: Jung
authors.affiliation: Division of Radiation Cancer Research, Korea Institute of Radiological & Medical Sciences, Seoul 139-706, Korea.
authors.forename: Seon Rang
authors.initials: SR
authors.lastname: Woo
authors.affiliation: Division of Radiation Cancer Research, Korea Institute of Radiological & Medical Sciences, Seoul 139-706, Korea.
authors.forename: Hyun-Yoo
authors.initials: HY
authors.lastname: Joo
authors.affiliation: Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul 133-791, Korea.
authors.forename: Su Hwa
authors.initials: SH
authors.lastname: Jang
authors.affiliation: Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul 133-791, Korea.
authors.forename: Hee Yong
authors.initials: HY
authors.lastname: Chung
authors.affiliation: Division of Radiation Cancer Research, Korea Institute of Radiological & Medical Sciences, Seoul 139-706, Korea.
authors.forename: Sung Hee
authors.initials: SH
authors.lastname: Hong
authors.affiliation: Laboratory of Toxicology, College of Veterinary Medicine, Seoul National University, Seoul 151-74-2, Korea.
authors.forename: Myung-Haing
authors.initials: MH
authors.lastname: Cho
authors.affiliation: Department of Physiology, College of Medicine, Korea University, Seoul 136-705, Korea.
authors.forename: Joong-Jean
authors.initials: JJ
authors.lastname: Park
authors.affiliation: Division of Radiation Cancer Research, Korea Institute of Radiological & Medical Sciences, Seoul 139-706, Korea.|College of Oriental Medicine, Kyung Hee University, 1 Hoegi-dong, Dongdaemun-gu, Seoul 130-701, Korea.
authors.forename: Miyong
authors.initials: M
authors.lastname: Yun
authors.affiliation: Division of Radiation Cancer Research, Korea Institute of Radiological & Medical Sciences, Seoul 139-706, Korea.
authors.forename: Kee-Ho
authors.initials: KH
authors.lastname: Lee
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D017209:Apoptosis; D018797:Cell Cycle Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D002470:Cell Survival; D016922:Cellular Senescence; D002999:Clone Cells / Q000166:cytology; D006801:Humans; D059566:M Phase Cell Cycle Checkpoints; D064246:Mad2 Proteins / Q000378:metabolism*; D051379:Mice; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D017384:Sequence Deletion
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D018797:Cell Cycle Proteins; C470309:MAD2L1BP protein, human; D064246:Mad2 Proteins; D009687:Nuclear Proteins