title: Expression and functional analysis of an inhibitor of apoptosis protein from Trichoplusia ni.
abstract: An inhibitor of the apoptosis protein (IAP) family gene from Trichoplusia ni, Tn-IAP1v, a variant of lepidopteran Tn-IAP1, was cloned by RT-PCR. There are six single nucleotide polymorphisms between the two Tn-IAP1 variants, resulting in three predicted single amino acid polymorphisms. With the GST fusion expression system, soluble recombinant Tn-IAP1v was highly expressed in Escherichia coli and then purified by affinity chromatography. Caspase inhibition assays indicated that recombinant Tn-IAP1v could specifically inhibit human caspase-9 in vitro instead of caspase-3, -7, and -8, which was further confirmed by the observation that recombinant Tn-IAP1v can directly bind caspase-9 in the protein pull-down assay. These results suggested that Tn-IAP1v might serve as an initiator caspase inhibitor in vivo in the conserved mitochondria apoptotic pathway.
authors.affiliation: Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, People's Republic of China.
authors.forename: Wen-Tao
authors.initials: WT
authors.lastname: Liao
authors.forename: Yang
authors.initials: Y
authors.lastname: Yang
authors.forename: Xiang-Fu
authors.initials: XF
authors.lastname: Wu
mesh_terms: D000818:Animals; D053453:Caspase 9; D020169:Caspases / Q000378:metabolism; D002460:Cell Line; D003001:Cloning, Molecular; D015853:Cysteine Proteinase Inhibitors / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology*; D003574:Cytochrome c Group / Q000037:antagonists & inhibitors; D003838:Deoxyadenine Nucleotides / Q000037:antagonists & inhibitors; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology*; D007915:Lepidoptera; D020641:Polymorphism, Single Nucleotide; D011506:Proteins; D044767:Ubiquitin-Protein Ligases
chemical_list: D015853:Cysteine Proteinase Inhibitors; D003574:Cytochrome c Group; D003838:Deoxyadenine Nucleotides; D051034:Inhibitor of Apoptosis Proteins; D019476:Insect Proteins; D011506:Proteins; C494833:BIRC2 protein, human; D044767:Ubiquitin-Protein Ligases; C506433:CASP9 protein, human; D053453:Caspase 9; D020169:Caspases; C026600:2'-deoxyadenosine triphosphate