Bracoviruses contain a large multigene family coding for protein tyrosine phosphatases.
The relationship between parasitic wasps and bracoviruses constitutes one of the few known mutualisms between viruses and eukaryotes. The virions produced in the wasp ovaries are injected into host lepidopteran larvae, where virus genes are expressed, allowing successful development of the parasite by inducing host immune suppression and developmental arrest. Bracovirus-bearing wasps have a common phylogenetic origin, and contemporary bracoviruses are hypothesized to have been inherited by chromosomal transmission from a virus that originally integrated into the genome of the common ancestor wasp living 73.7 +/- 10 million years ago. However, so far no conserved genes have been described among different braconid wasp subfamilies. Here we show that a gene family is present in bracoviruses of different braconid wasp subfamilies (Cotesia congregata, Microgastrinae, and Toxoneuron nigriceps, Cardiochilinae) which likely corresponds to an ancient component of the bracovirus genome that might have been present in the ancestral virus. The genes encode proteins belonging to the protein tyrosine phosphatase family, known to play a key role in the control of signal transduction pathways. Bracovirus protein tyrosine phosphatase genes were shown to be expressed in different tissues of parasitized hosts, and two protein tyrosine phosphatases were produced with recombinant baculoviruses and tested for their biochemical activity. One protein tyrosine phosphatase is a functional phosphatase. These results strengthen the hypothesis that protein tyrosine phosphatases are involved in virally induced alterations of host physiology during parasitism.
Provost
Bertille
B
Institut de Recherche sur la Biologie de l'Insecte, UMR CNRS 6035, Faculté des Sciences et Techniques, Parc Grandmont, 37200 Tours, France.
Varricchio
Paola
P
Arana
Eloisa
E
Espagne
Eric
E
Falabella
Patrizia
P
Huguet
Elisabeth
E
La Scaleia
Raffaella
R
Cattolico
Laurence
L
Poirié
Marylène
M
Malva
Carla
C
Olszewski
Julie A
JA
Pennacchio
Francesco
F
Drezen
Jean-Michel
JM
D000595:Amino Acid Sequence; D000818:Animals; D008969:Molecular Sequence Data; D005810:Multigene Family; D018071:Polydnaviridae / Q000235:genetics*; D017027:Protein Tyrosine Phosphatases / Q000235:genetics*
D017027:Protein Tyrosine Phosphatases