Sequence structure and expression pattern of a novel anionic defensin-like gene from silkworm (Bombyx mori).
A defensin-like gene, BmdefA, was rediscovered in the silkworm genome and expressed sequence tags databases. The open reading frame of BmdefA encodes a prepropeptide consisting of a 22-residue signal peptide, a 34-residue propeptide, and a 36-residue mature peptide with a molecular mass of 4.0 kDa. The mature peptide possesses the characteristic six-cysteine motif of insect defensins, and its predicted isoelectric point is 4.12, indicating it is a novel anionic defensin. An intron is present in BmdefA and several cis-regulatory elements are in the regulating region. It is transcribed constitutively at a high level in the hemocyte, silk gland, head, and ovary of the silkworm larvae, and in the fat body of early-stage pupae and moth. BmdefA is also strongly induced by immune challenge. These results suggest that BmdefA plays an important role in both immunity and metamorphosis.
Wen
Hongxiu
H
Department of Applied Biology, Faculty of Textile Science and Technology, Shinshu University, Ueda, Nagano 386-8567, Japan.
Lan
Xiqian
X
Cheng
Tingcai
T
He
Ningjia
N
Shiomi
Kunihiro
K
Kajiura
Zenta
Z
Zhou
Zeyang
Z
Xia
Qingyou
Q
Xiang
Zhonghuai
Z
Nakagaki
Masao
M
D000595:Amino Acid Sequence; D000818:Animals; D000838:Anions / Q000737:chemistry; D001483:Base Sequence; D012831:Bombyx / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D017124:Conserved Sequence; D023082:Defensins / Q000737:chemistry* / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000235:genetics*; D049750:Genome, Insect / Q000235:genetics; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D014158:Transcription, Genetic / Q000235:genetics
D000838:Anions; D023082:Defensins