Two isoforms of a member of the arthropod defensin family from the soft tick, Ornithodoros moubata (Acari : Argasidae)

Citation
Y. Nakajima et al., Two isoforms of a member of the arthropod defensin family from the soft tick, Ornithodoros moubata (Acari : Argasidae), INSEC BIO M, 31(8), 2001, pp. 747-751
Citations number
25
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Entomology/Pest Control","Biochemistry & Biophysics
Journal title
INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY
ISSN journal
0965-1748 → ACNP
Volume
31
Issue
8
Year of publication
2001
Pages
747 - 751
Database
ISI
SICI code
0965-1748(20010622)31:8<747:TIOAMO>2.0.ZU;2-E
Abstract
We previously purified and determined the partial amino acid sequence of a 4 kDa peptide having high homology with scorpion defensin from the hemolymp h of adult fed female soft ticks, Ornithodoros moubata. In this study, the full length sequences of two defensin isoforms were obtained. Deduced amino acid sequences reveal a precursor protein of 73 amino acid residues with a mature portion consisting of 37 amino acid residues. This mature peptide c ontains six cysteine residues conserved in the same location as other inver tebrate defensins. Phylogenetic analysis reveals that Ornithodoros defensin is most closely related to scorpion defensin and other more ancient arthro pods. Ornithodoros defensin mRNA is constitutively expressed and up-regulat ed by blood-feeding and bacterial injection. Ornithodoros defensin gene exp ression occurs mainly in the midgut. This is the first report of the clonin g and gene expression of an antibacterial peptide from the Acari. (C) 2001 Elsevier Science Ltd. All rights reserved.