Expression and characterization of cDNAs for cecropin B, an antibacterial protein of the silkworm, Bombyx mori.
To analyze the induction mechanism of antibacterial protein gene expression, cDNAs coding for cecropin B have been cloned from the B. mori fat body cDNA library. Nucleotide sequences of two positive clones were determined and their amino acid sequences deduced. They revealed that these clones coded for the same cecropin, which is identical to purified cecropin B. However, the cDNAs contained different nucleotides at the third codon position and 5' or 3' non-coding regions. Results obtained by Northern blot analysis showed that the gene expression of B. mori cecropin B was rapidly induced by Escherichia coli and reached maximum levels 8 h after immunization. The expression of cecropin B gene occurred specifically in tissues, mainly in the fat body and hemocytes.
Kato
Y
Y
Laboratory of Biological Defense, National Institute of Sericultural and Entomological Science, Ibaraki, Japan.
Taniai
K
K
Hirochika
H
H
Yamakawa
M
M
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D012831:Bombyx / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics*; D015342:DNA Probes; D004926:Escherichia coli / Q000235:genetics; D005216:Fat Body / Q000378:metabolism; D015870:Gene Expression; D006434:Hemocytes / Q000378:metabolism; D007301:Insect Hormones / Q000096:biosynthesis / Q000235:genetics*; D019476:Insect Proteins; D008969:Molecular Sequence Data; D014018:Tissue Distribution
D015342:DNA Probes; D007301:Insect Hormones; D019476:Insect Proteins; C031162:cecropin B protein, Insecta; D004247:DNA