TY - JOUR T1 - Cloning and characterization of a trypsin-encoding cDNA of the human body louse Pediculus humanus JF - Insect Molecular Biology Y1 - 2004 DO - 10.1111/j.1365-2583.2004.00453.x A1 - Kollien,A. H. A1 - Waniek,P. J. A1 - Pröls,F. A1 - Habedank,Birgit A1 - Schaub,G. A. SP - 9 EP - 18 KW - Amino Acids KW - animals KW - Base Sequence KW - Blotting, Northern KW - Comparative Study KW - dna KW - electrophoresis KW - genes KW - Molecular Sequence Data KW - Pediculus KW - polymerase KW - Research Support, Non-U.S. Gov't KW - sequence KW - Transition Temperature KW - Trypsin/genetics AB -

From a cDNA library of the whole insect, a trypsin gene of Pediculus humanus has been cloned and sequenced. The 908 bp clone has an open reading frame of 759 bp, which encodes a pre-proenzyme with 253 amino acid residues. A sixteen-residue N-terminal signal peptide is followed by a twelve-residue activation peptide with putative cleavage sites at Gly16 and Tyr28. The deduced amino acid sequence has several features typical of trypsin proteases and an overall identity of 35-43% with the trypsins of several haematophagous Diptera. The 1.0 kb genomic trypsin gene contains three introns of 102, 79 and 80 nucleotides following the codons for Gly16, Gln74 and Ala155, respectively. Only a single gene seems to be present. In Northern blot analysis, unfed first instar larvae have an identical or slightly lower level of trypsin mRNA than fed adult lice, and in adults 2-24 h after the bloodmeal this gene shows a constitutive expression. After in vitro transcription and translation, the activation peptide is cleaved by chymotrypsin, a so far unreported phenomenon in trypsin activation.

CY - England VL - 13 SN - 0962-1075 UR - http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2583.2004.00453.x/epdf IS - 1 N1 - LR: 20041117; JID: 9303579; 0 (DNA Primers); EC 3.4.21.4 (Trypsin); ppublish ER -