In vitro and in silico analysis of signal peptides from the human blood fluke, Schistosoma mansoni.
Proteins secreted by and anchored on the surfaces of parasites are in intimate contact with host tissues. The transcriptome of infective cercariae of the blood fluke, Schistosoma mansoni, was screened using signal sequence trap to isolate cDNAs encoding predicted proteins with an N-terminal signal peptide. Twenty cDNA fragments were identified, most of which contained predicted signal peptides or transmembrane regions, including a novel putative seven-transmembrane receptor and a membrane-associated mitogen-activated protein kinase. The developmental expression pattern within different life-cycle stages ranged from ubiquitous to a transcript that was highly upregulated in the cercaria. A bioinformatics-based comparison of 100 signal peptides from each of schistosomes, humans, a parasitic nematode and Escherichia coli showed that differences in the sequence composition of signal peptides, notably the residues flanking the predicted cleavage site, might account for the negative bias exhibited in the processing of schistosome signal peptides in mammalian cells.
Pearson
Mark S
MS
Division of Infectious Diseases and Immunology, Australian Centre for International and Tropical Health and Nutrition, Queensland Institute of Medical Research and The University of Queensland, 300 Herston Road, Brisbane, QLD 4006, Australia.
McManus
Donald P
DP
Smyth
Danielle J
DJ
Lewis
Fred A
FA
Loukas
Alex
A
D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics; D019556:COS Cells; D000252:Calcium-Transporting ATPases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D002522:Chlorocebus aethiops; D018509:DNA, Helminth / Q000235:genetics / Q000302:isolation & purification; D053418:Death Domain Receptor Signaling Adaptor Proteins; D004926:Escherichia coli / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D017238:Genes, Helminth; D020662:Guanine Nucleotide Exchange Factors / Q000235:genetics; D015801:Helminth Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D051379:Mice; D008969:Molecular Sequence Data; D011499:Protein Processing, Post-Translational; D021382:Protein Sorting Signals / Q000235:genetics*; D012550:Schistosoma mansoni / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014162:Transfection
D001426:Bacterial Proteins; D018509:DNA, Helminth; D053418:Death Domain Receptor Signaling Adaptor Proteins; D020662:Guanine Nucleotide Exchange Factors; D015801:Helminth Proteins; C491371:Madd protein, mouse; D021382:Protein Sorting Signals; D000252:Calcium-Transporting ATPases