Insect immunity. Isolation of cDNA clones corresponding to diptericin, an inducible antibacterial peptide from Phormia terranovae (Diptera). Transcriptional profiles during immunization.
We have previously isolated and characterized a family of novel 8-kDa cationic antibacterial peptides synthesized by larvae of Phormia terranovae (Diptera) in response to various injuries. These molecules have been named diptericins. The peptide sequence of diptericin A was used to prepare oligonucleotides for screening cDNA libraries and we report in the present paper the isolation of several cDNA clones encoding diptericin. The analysis of the nucleotide sequences indicates that diptericin is synthesized as a prepeptide which is matured in two steps: (a) cleavage of a signal peptide and (b) amidation of the C-terminal residue. Interestingly, the 3' untranslated region of the mRNA contains a consensus sequence TTATTTAT which is also observed in the mRNA of another insect antibacterial peptide (attacin-related sarcotoxin IIA) and in mRNAs encoding proteins related to the inflammatory response in mammals. Our data illustrate that diptericins form a polymorphic family of immune peptides. The transcription of the diptericin genes is rapidly induced in the fat body after inoculation of bacteria, as evidenced by the transcriptional profile.
Reichhart
J M
JM
Laboratoire de Biologie Générale, Université Louis Pasteur, UA CNRS 672 Endocrinologie et Immunologie des Insectes, Strasbourg, France.
Essrich
M
M
Dimarcq
J L
JL
Hoffmann
D
D
Hoffmann
J A
JA
Lagueux
M
M
D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000096:biosynthesis*; D001426:Bacterial Proteins / Q000494:pharmacology*; D001483:Base Sequence; D015152:Blotting, Northern; D004247:DNA / Q000302:isolation & purification; D004175:Diptera / Q000235:genetics / Q000276:immunology*; D029721:Drosophila Proteins; D004722:Endoribonucleases; D004754:Enterobacter; D004755:Enterobacteriaceae; D005786:Gene Expression Regulation; D005802:Genes, MHC Class II; D007301:Insect Hormones / Q000096:biosynthesis* / Q000235:genetics; D019476:Insect Proteins; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000032:analysis; D016914:Ribonuclease H; D014158:Transcription, Genetic / Q000187:drug effects
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; C054756:DptA protein, Drosophila; D029721:Drosophila Proteins; D007301:Insect Hormones; D019476:Insect Proteins; D012333:RNA, Messenger; D004247:DNA; D004722:Endoribonucleases; D016914:Ribonuclease H