Isolation and characterization of a new apoptosis-inducing factor

2010 Fiscal Year Final Research Report

• Project/Area Number: 20570007
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Genetics/Genome dynamics
• Research Institution: Fukuoka Dental College
• Principal Investigator: HIDAKA Masumi Fukuoka Dental College, 歯学部, 教授 (80238310)
• Co-Investigator(Renkei-kenkyūsha): NAKATSU Yoshimichi 九州大学, 医学(系)研究院, 准教授 (00207820)
• Project Period (FY): 2008 – 2010
• Keywords: DNA損傷 / アルキル化剤 / アポトーシス / 遺伝子トラップ法 / 突然変異 / 発がん抑制 / 分子遺伝学 / ミスマッチ修復タンパク質

Research Abstract

O^6-Methylguanine (O^6-mG), produced in DNA by the action of simple alkylating agents, induces base mispairing during DNA replication and is thus responsible for the induction of mutations as well as tumors. To prevent such an outcome, organisms possess a mechanism to eliminate cells carrying O^6-mG by inducing apoptosis in a mismatch repair protein-dependent manner. To understand the molecular mechanism of O^6-mG-induced apoptosis, we carried out retrovirus-mediated gene-trap mutagenesis, followed by the selection of MNU-resistant clones from MNU-sensitive Mgmt^<-/-> cells. One of the mutants has an insertional mutation in a novel gene, designated Mapo1, and was unable to induce mitochondrial membrane depolarization and caspase-3 activation, hallmarks for the induction of apoptosis, after treatment with MNU. The flag-tagged MAPO1 protein expressed in cells was revealed to be associated with FLCN and AMPK. By the introduction of siRNAs specific for these genes, the production of sub-G_1 population of cells following MNU treatment was severely suppressed, suggesting the important role of MAPO1-containing protein complex in the induction of apoptosis triggered by O^6-mG.

Research Products

• [Journal Article] A novel protein, MAPO1, that functions in apoptosis triggered by O^6-methylguanine mispair in DNA. (2009)
  • Author(s): Komori K, Takagi Y, Sanada M, Lim T-H, Nakatsu Y, Tsuzuki T, Sekiguchi M, Hidaka M
  • Journal Title: Oncogene 28 Pages: 1142-1150
  • Peer Reviewed
• [Journal Article] Different initial steps of apoptosis induced by two types of antineoplastic drugs. (2008)
  • Author(s): Takagi Y, Hidaka M, Sanada M, Yoshida H, Sekiguchi M
  • Journal Title: Biochem.Pharmacol. 76 Pages: 303-311
  • Peer Reviewed
• [Presentation] Genome Integrity Preserved by Induction of Apoptosis from DNA Damage. (2010)
  • Author(s): Hidaka M, Sekiguchi M
  • Organizer: The 57th NIBB Conference on Dynamic Genome.
  • Place of Presentation: Okazaki, Japan
  • Year and Date: 2010-10-16
• [Presentation] 哺乳類細胞のゲノム安定性と細胞死 (2010)
  • Author(s): 日高真純、高木康光、林徳豪、中津可道、續輝久、佐野しおり、坂上竜資、関口睦夫
  • Organizer: 第82回大会日本遺伝学会
  • Year and Date: 2010-09-20
• [Presentation] MAPO1 plays a role in the induction of apoptosis to preserve genome integrity from environmental stress. (2009)
  • Author(s): Hidaka M, Komori K, Takagi Y, Sanada M, Lim T-H, 中津可道, Tsuzuki T, Sekiguchi M
  • Organizer: 第32回日本分子生物学会年会
  • Year and Date: 2009-12-10
• [Presentation] Characterization of Mapo1-defective mutant that is unable to induce apoptosis triggered by alkylated DNA damage. (2009)
  • Author(s): Lim T-H, Hidaka M, Nakatsu Y, Sekiguchi M, Tsuzuki T
  • Organizer: 第32回日本分子生物学会年会
  • Year and Date: 2009-12-10
• [Presentation] A genetical approach to identify new genes related to apoptosis induced by alkylated DNA damage. (2009)
  • Author(s): Sanada M, Takagi Y, Sekiguchi M, Hidaka M.
  • Organizer: 第68回日本癌学会学術総会
  • Year and Date: 2009-10-01
• [Presentation] アルキル化損傷誘導アポトーシス経路で機能するMAPO1タンパク質複合体 (2009)
  • Author(s): 日高真純,高木康光,真田正幸,Lim Teik-How,中津可道,續輝久,関口睦夫
  • Organizer: 第81回大会日本遺伝学会
  • Year and Date: 2009-09-16
• [Presentation] A new member of genes, Mapo1, involve in O^6-methylguanine-induced apoptosis. (2009)
  • Author(s): Hidaka M, Komori K, Takagi Y, Sanada M, Lim T-H, Nakatsu Y, Tsuzuki T, Sekiguchi M
  • Organizer: The 3rd ASM Conference on DNA Repair and Mutagenesis.
  • Place of Presentation: Whistler, BC, Canada
  • Year and Date: 2009-06-01
• [Presentation] Identification of a novel apoptosis-inducing gene, Mapo1, using a method of retrovirus-mediated gene-trap mutagenesis. (2008)
  • Author(s): Hidaka M, Komori K, Takagi Y, Sanada M, Lim T-H, Nakatsu Y, Tsuzuki T, Sekiguchi M
  • Organizer: The 6th 3R Symposium.
  • Place of Presentation: Tsumagoi, Japan
  • Year and Date: 20081027-20081030
• [Presentation] アルキル化損傷で誘導されるアポトーシス経路で機能する新規遺伝子Mapo1 (2008)
  • Author(s): 日高真純,小森加代子,高木康光,真田正幸,Teik-How Lim,中津可道,續輝久,関口睦夫
  • Organizer: 第80回日本遺伝学会
  • Year and Date: 20080903-20080905
• [Presentation] Distinct pathways of apoptosis induced by alkylated DNA damage. (2008)
  • Author(s): Hidaka M, Sanada M, Takagi Y, Lim T-H, Nakatsu Y, Tsuzuki T, Sekiguchi M
  • Organizer: The International Ataxia-Telangiectasia Workshop 2008
  • Place of Presentation: Ohtsu, Japan
  • Year and Date: 20080422-20080426
• [Remarks] ホームページ等