Insect immunity. Constitutive expression of a cysteine-rich antifungal and a linear antibacterial peptide in a termite insect.
Two novel antimicrobial peptides, which we propose to name termicin and spinigerin, have been isolated from the fungus-growing termite Pseudacanthotermes spiniger (heterometabole insect, Isoptera). Termicin is a 36-amino acid residue antifungal peptide, with six cysteines arranged in a disulfide array similar to that of insect defensins. In contrast to most insect defensins, termicin is C-terminally amidated. Spinigerin consists of 25 amino acids and is devoid of cysteines. It is active against bacteria and fungi. Termicin and spinigerin show no obvious sequence similarities with other peptides. Termicin is constitutively present in hemocyte granules and in salivary glands. The presence of termicin and spinigerin in unchallenged termites contrasts with observations in evolutionary recent insects or insects undergoing complete metamorphosis, in which antimicrobial peptides are induced in the fat body and released into the hemolymph after septic injury.
Lamberty
M
M
Institut de Biologie Moléculaire et Cellulaire, Unité Propre de Recherche 9022, CNRS, "Réponse Immunitaire et Développement chez les Insectes," 15 rue René Descartes, 67084 Strasbourg Cedex, France.
Zachary
D
D
Lanot
R
R
Bordereau
C
C
Robert
A
A
Hoffmann
J A
JA
Bulet
P
P
D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D000935:Antifungal Agents / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D023181:Antimicrobial Cationic Peptides; D001483:Base Sequence; D002851:Chromatography, High Pressure Liquid; D003545:Cysteine / Q000737:chemistry*; D017931:DNA Primers; D007150:Immunohistochemistry; D020049:Isoptera / Q000276:immunology*; D008969:Molecular Sequence Data; D010455:Peptides; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D017386:Sequence Homology, Amino Acid
D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D023181:Antimicrobial Cationic Peptides; D017931:DNA Primers; D010455:Peptides; D011994:Recombinant Proteins; C428303:spinigerin; C428304:termicin; D003545:Cysteine