title: Molecular cloning and characterization of CIDE-3, a novel member of the cell-death-inducing DNA-fragmentation-factor (DFF45)-like effector family.
abstract: DNA fragmentation is one of the critical steps in apoptosis, which is induced by DNA fragmentation factor (DFF). DFF is composed of two subunits, a 40 kDa caspase-activated nuclease (DFF40) and a 45 kDa inhibitor (DFF45). Recently a novel family of cell-death-inducing DFF45-like effectors (CIDEs) has been identified. Among CIDEs, two from human (CIDE-A and CIDE-B) and three from mouse (CIDE-A, CIDE-B and FSP27) have been reported. In this study human CIDE-3, a novel member of CIDEs, was identified upon sequence analysis of a previously unidentified cDNA that encoded a protein of 238 amino acids. It was shown to be a human homologue of mouse FSP27, and shared homology with the CIDE-N and CIDE-C domains of CIDEs. Apoptosis-inducing activity was clearly shown by DNA-fragmentation assay of the nuclear DNA of CIDE-3 transfected 293T cells. The expression pattern of CIDE-3 was different from that of CIDE-B. As shown by Northern-blot analysis, CIDE-3 was expressed mainly in human small intestine, heart, colon and stomach, while CIDE-B showed strong expression in liver and small intestine and at a lower level in colon, kidney and spleen. Green-fluorescent-protein-tagged CIDE-3 was revealed in some cytosolic corpuscles. Alternative splicing of the CIDE-3 gene was also identified by reverse transcription PCR, revealing that two transcripts, CIDE-3 and CIDE-3alpha, were present in HepG2 and A375 cells. CIDE-3 comprised a full-length open reading frame with 238 amino acids; in CIDE-3alpha exon 3 was deleted and it encoded a protein of 164 amino acids. Interestingly the CIDE-3alpha isoform still kept the apoptosis-inducing activity and showed the same pattern of subcellular localization as CIDE-3. Consistent with its chromosome localization at 3p25, a region associated with high frequency loss of heterozygosity in many tumours, CIDE-3 may play an important role in prevention of tumorigenesis.
authors.affiliation: State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Liang
authors.forename: Mujun
authors.initials: M
authors.lastname: Zhao
authors.forename: Zhenhua
authors.initials: Z
authors.lastname: Xu
authors.forename: Kazunari K
authors.initials: KK
authors.lastname: Yokoyama
authors.forename: Tsaiping
authors.initials: T
authors.lastname: Li
mesh_terms: D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis; D051017:Apoptosis Regulatory Proteins; D001483:Base Sequence; D015152:Blotting, Northern; D015153:Blotting, Western; D019556:COS Cells; D002460:Cell Line; D002874:Chromosome Mapping; D002893:Chromosomes, Human, Pair 3; D003001:Cloning, Molecular; D018076:DNA, Complementary; D005091:Exons; D006801:Humans; D007438:Introns; D008969:Molecular Sequence Data; D011506:Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D013347:Subcellular Fractions / Q000378:metabolism
chemical_list: D051017:Apoptosis Regulatory Proteins; C472088:CIDEC protein, human; D018076:DNA, Complementary; D011506:Proteins; D012333:RNA, Messenger; C109664:caspase-activated DNase inhibitor