RESUMO
We have characterized by molecular cloning and sequencing a Plasmodium chabaudi antigen that is associated with the membrane of the infected erythrocyte throughout the entire intraerythrocytic cycle. The protein (PcEMA1) has a predicted size of 50 kDa and contains a major tandem repeat array of 16 octapeptides that constitutes almost 30% of the protein. At its amino-terminus, PcEMA1 has a string of hydrophobic residues characteristic of a secreted protein, but does not contain a hydrophobic membrane-spanning segment. The antigen appears to reside on the cytoplasmic face of the erythrocytic membrane. PcEMA1 has a predicted pI of 4.4 and is a potential phosphoprotein.
Assuntos
Fosfoproteínas/genética , Plasmodium chabaudi/genética , Proteínas de Protozoários/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular , DNA de Protozoário/genética , Membrana Eritrocítica/metabolismo , Genes de Protozoários , Interações Hospedeiro-Parasita , Dados de Sequência Molecular , Peso Molecular , Fosfoproteínas/isolamento & purificação , Fosfoproteínas/metabolismo , Plasmodium chabaudi/crescimento & desenvolvimento , Plasmodium chabaudi/metabolismo , Proteínas de Protozoários/isolamento & purificação , Proteínas de Protozoários/metabolismo , Sequências Repetitivas de Ácido NucleicoRESUMO
About 7,000 recombinant clones, derived from chromosomally-identified families of wild-caught females of Anopheles dirus species D, were screened. The most promising clone was totally specific to species D when tested against single F1 females of all four species of the complex. In fresh specimens the clone was positive for DNA levels 150 times less than the normal DNA content of single individuals. Fresh adult males and females, larvae, and dried specimens have been successfully identified. The clone was sequenced; it is 124 bp long and appears to be repeated in the genome about 1.8 x 10(4) times.