BmICE-2 is a novel pro-apoptotic caspase involved in apoptosis in the silkworm, Bombyx mori.
In this study we identified a potential pro-apoptotic caspase gene, Bombyx mori(B. mori)ICE-2 (BmICE-2) which encoded a polypeptide of 284 amino acid residues, including a (169)QACRG(173) sequence which surrounded the catalytic site and contained a p20 and a p10 domain. BmICE-2 expressed in Escherichia coli (E. coli) exhibited high proteolytic activity for the synthetic human initiator caspase-9 substrates Ac-LEHD-pNA, but little activity towards the effector caspase-3 substrates Ac-DEVD-pNA. When BmICE-2 was transiently expressed in BmN-SWU1 silkworm B. mori cells, we found that the high proteolytic activity for Ac-LEHD-pNA triggered caspase-3-like protease activity resulting in spontaneous cleavage and apoptosis in these cells. This effect was not replicated in Spodoptera frugiperda 9 cells. In addition, spontaneous cleavage of endogenous BmICE-2 in BmN-SWU1 cells could be induced by actinomycin D. These results suggest that BmICE-2 may be a novel pro-apoptotic gene with caspase-9 activity which is involved apoptotic processes in BmN-SWU1 silkworm B. mori cells.
State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China.
Hua-Shan
HS
Yi
State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China.
Cai-Xia
CX
Pan
State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China.
Chun
C
Pan
State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China.
Juan
J
Song
State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China.
Yan-Fen
YF
Hu
State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China.
La
L
Wang
State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China; Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing 400716, China. Electronic address: pmh0476@hotmail.com.
Min-Hui
MH
Pan
State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China; Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing 400716, China. Electronic address: lucheng@swu.edu.cn.
Cheng
C
Lu
D000818:Animals; D017209:Apoptosis; D012831:Bombyx / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D053453:Caspase 9 / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D003609:Dactinomycin / Q000494:pharmacology; D004926:Escherichia coli / Q000235:genetics; D006801:Humans; D015151:Immunoblotting; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism*; D018613:Microscopy, Confocal; D059748:Proteolysis / Q000187:drug effects; D011994:Recombinant Proteins / Q000378:metabolism; D061987:Sf9 Cells; D013045:Species Specificity; D018411:Spodoptera; D013379:Substrate Specificity
D019476:Insect Proteins; D011994:Recombinant Proteins; D003609:Dactinomycin; D053453:Caspase 9; C588101:ICE-2 protein, Bombyx mori
Apoptosis; BmICE-2; Bombyx mori; Caspase