Isolation and expression of cathepsin B cDNA in hemocytes during metamorphosis of Bombyx mori.
By using RT-PCR and 5'- and 3'-RACE methods, we isolated cathepsin B cDNA from hemocytes of Bombyx mori. The predicted open reading frame encoded 337 amino acids with 54% identity with the human cathepsin B, and 55% identity with the 29-kDa proteinase of the blowfly. Three active sites characteristic for cathepsin B were conserved in the deduced amino acid sequences of BmCtB cDNA at positions Cys-111, His-280 and Asn-300. Northern analysis identified a 1.3-kb mRNA. Expression of BmCtB was observed in the hemocytes from the day of wandering and was strongest at day 1 pupa. With in situ hybridization, strong signals were observed in the granular cells and plasmatocytes of day 0 pupa, but not in those of day 5 of the fifth larval instar. The results indicate another function of cathepsin B and insect hemocyte during metamorphosis.
Xu
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Y
College of Animal Sciences, Zhejiang University, 310029, Hangzhou, PR China
Kawasaki
H
H
D000595:Amino Acid Sequence; D000818:Animals; D012831:Bombyx / Q000166:cytology / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development*; D002401:Cathepsin B / Q000737:chemistry / Q000235:genetics*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D006434:Hemocytes / Q000201:enzymology*; D017403:In Situ Hybridization; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics; D008675:Metamorphosis, Biological; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid
D018076:DNA, Complementary; D019476:Insect Proteins; D012333:RNA, Messenger; D002401:Cathepsin B