کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1982306 | 1062276 | 2011 | 13 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Cloning and characterization of a dronc homologue in the silkworm, Bombyx mori Cloning and characterization of a dronc homologue in the silkworm, Bombyx mori](/preview/png/1982306.png)
We cloned and characterized a novel Bombyx mori homologue (bm-dronc) of Drosophila melanogaster dronc (dm-dronc), which could encode a polypeptide of 438 amino acid residues. Bm-Dronc shares relatively low amino acid sequence identities of 25% and 26% with Dm-Dronc and Aedes aegypti Dronc (Aa-Dronc), respectively. Bm-Dronc has the sequence QACRG surrounding the catalytic site (C), which is consistent with the QAC(R/Q/G)(G/E) consensus sequence in most caspases but distinct from the sequences PFCRG and SICRG of Dm-Dronc and Aa-Dronc, respectively. Bm-Dronc possesses a long N-terminal prodomain containing a caspase recruitment domain (CARD), a p20 domain and a p10 domain, exhibiting cleavage activities on synthetic substrates Ac-VDVAD-AMC, Ac-IETD-AMC and Ac-LEHD-AMC, which are preferred by human initiator caspases-2, -8 and -9, respectively. Bm-Dronc transiently expressed in insect cells and Escherichia coli cells underwent spontaneous cleavage and caused apoptosis and stimulation of caspase-3-like protease activity in various lepidopteran cell lines, but not in the dipteran cell line D. melanogaster S2. The apoptosis and the stimulation of caspase-3-like protease activity induced by Bm-Dronc overexpression were abrogated upon transfection with either a double-stranded RNA against bm-dronc or a plasmid expressing functional anti-apoptotic protein Hycu-IAP3 encoded by the baculovirus Hyphantria cunea multiple nucleopolyhedrovirus (MNPV). Apoptosis induction in BM-N cells by infection with a p35-defective Autographa californica MNPV or exposure to actinomycin D and UV promoted the cleavage of Bm-Dronc. These results indicate that Bm-Dronc serves as the initiator caspase responsible for the induction of caspase-dependent apoptosis.
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► We cloned and characterized a Bombyx mori homologue (bm-dronc) of Drosophila melanogaster dronc.
► Bm-Dronc transiently expressed in insect cells underwent spontaneous cleavage and caused apoptosis.
► Apoptosis induction by infection with vAcΔp35 or exposure to actinomycin D and UV promoted the cleavage of Bm-Dronc.
► The apoptosis was abrogated by knockdown of Bm-Dronc either by RNA interference or Hycu-IAP3 transient expression.
Journal: Insect Biochemistry and Molecular Biology - Volume 41, Issue 11, November 2011, Pages 909–921