%0 Journal Article %1 harcus_signal_2004 %A Harcus, Yvonne %A Parkinson, John %A Fernandez, Cecilia %A Daub, Jennifer %A Selkirk, Murray %A Blaxter, Mark %A Maizels, Rick %D 2004 %J Genome Biology %K imported %N 6 %P R39 %R 10.1186/gb-2004-5-6-r39 %T Signal sequence analysis of expressed sequence tags from the nematode Nippostrongylus brasiliensis and the evolution of secreted proteins in parasites %V 5 %X BACKGROUND:Parasitism is a highly successful mode of life and one that requires suites of gene adaptations to permit survival within a potentially hostile host. Among such adaptations is the secretion of proteins capable of modifying or manipulating the host environment. Nippostrongylus brasiliensis is a well-studied model nematode parasite of rodents, which secretes products known to modulate host immunity.RESULTS:Taking a genomic approach to characterize potential secreted products, we analyzed expressed sequence tag (EST) sequences for putative amino-terminal secretory signals. We sequenced ESTs from a cDNA library constructed by oligo-capping to select full-length cDNAs, as well as from conventional cDNA libraries. SignalP analysis was applied to predicted open reading frames, to identify potential signal peptides and anchors. Among 1,234 ESTs, 197 (˜16\%) contain predicted 5' signal sequences, with 176 classified as conventional signal peptides and 21 as signal anchors. ESTs cluster into 742 distinct genes, of which 135 (18\%) bear predicted signal-sequence coding regions. Comparisons of clusters with homologs from Caenorhabditis elegans and more distantly related organisms reveal that the majority (65\% at P \textless e-10) of signal peptide-bearing sequences from N. brasiliensis show no similarity to previously reported genes, and less than 10\% align to conserved genes recorded outside the phylum Nematoda. Of all novel sequences identified, 32\% contained predicted signal peptides, whereas this was the case for only 3.4\% of conserved genes with sequence homologies beyond the Nematoda.CONCLUSIONS:These results indicate that secreted proteins may be undergoing accelerated evolution, either because of relaxed functional constraints, or in response to stronger selective pressure from host immunity.

@article{harcus_signal_2004, abstract = {{BACKGROUND:Parasitism} is a highly successful mode of life and one that requires suites of gene adaptations to permit survival within a potentially hostile host. Among such adaptations is the secretion of proteins capable of modifying or manipulating the host environment. Nippostrongylus brasiliensis is a well-studied model nematode parasite of rodents, which secretes products known to modulate host {immunity.RESULTS:Taking} a genomic approach to characterize potential secreted products, we analyzed expressed sequence tag {(EST)} sequences for putative amino-terminal secretory signals. We sequenced {ESTs} from a {cDNA} library constructed by oligo-capping to select full-length {cDNAs,} as well as from conventional {cDNA} libraries. {SignalP} analysis was applied to predicted open reading frames, to identify potential signal peptides and anchors. Among 1,234 {ESTs,} 197 ({\textasciitilde}16\%) contain predicted 5' signal sequences, with 176 classified as conventional signal peptides and 21 as signal anchors. {ESTs} cluster into 742 distinct genes, of which 135 (18\%) bear predicted signal-sequence coding regions. Comparisons of clusters with homologs from Caenorhabditis elegans and more distantly related organisms reveal that the majority (65\% at P {\textless} e-10) of signal peptide-bearing sequences from N. brasiliensis show no similarity to previously reported genes, and less than 10\% align to conserved genes recorded outside the phylum Nematoda. Of all novel sequences identified, 32\% contained predicted signal peptides, whereas this was the case for only 3.4\% of conserved genes with sequence homologies beyond the {Nematoda.CONCLUSIONS:These} results indicate that secreted proteins may be undergoing accelerated evolution, either because of relaxed functional constraints, or in response to stronger selective pressure from host immunity.}, added-at = {2009-12-09T17:59:08.000+0100}, author = {Harcus, Yvonne and Parkinson, John and Fernandez, Cecilia and Daub, Jennifer and Selkirk, Murray and Blaxter, Mark and Maizels, Rick}, biburl = {https://www.bibsonomy.org/bibtex/269319fa5a5af00c2fcba83c1386f2b26/derele}, description = {my big master bibtex file}, doi = {10.1186/gb-2004-5-6-r39}, interhash = {f8091a5c2888b754198a18ab04c8ad2c}, intrahash = {69319fa5a5af00c2fcba83c1386f2b26}, issn = {1465-6906}, journal = {Genome Biology}, keywords = {imported}, number = 6, opturl = {http://genomebiology.com/2004/5/6/R39}, pages = {R39}, timestamp = {2009-12-09T18:00:10.000+0100}, title = {Signal sequence analysis of expressed sequence tags from the nematode Nippostrongylus brasiliensis and the evolution of secreted proteins in parasites}, volume = 5, year = 2004 }