Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10940780 | Immunobiology | 2016 | 11 Pages |
Abstract
A transcriptome analysis of the venom glands of the spider Loxosceles laeta, performed by our group, in a previous study (Fernandes-Pedrosa et al., 2008), revealed a transcript with a sequence similar to the human complement component C3. Here we present the analysis of this transcript. cDNA fragments encoding the C3 homologue (Lox-C3) were amplified from total RNA isolated from the venom glands of L. laeta by RACE-PCR. Lox-C3 is a 5178 bps cDNA sequence encoding a 190Â kDa protein, with a domain configuration similar to human C3. Multiple alignments of C3-like proteins revealed two processing sites, suggesting that Lox-C3 is composed of three chains. Furthermore, the amino acids consensus sequences for the thioester was found, in addition to putative sequences responsible for FB binding. The phylogenetic analysis showed that Lox-C3 belongs to the same group as two C3 isoforms from the spider Hasarius adansoni (Family Salcitidae), showing 53% homology with these. This is the first characterization of a Loxosceles cDNA sequence encoding a human C3 homologue, and this finding, together with our previous finding of the expression of a FB-like molecule, suggests that this spider species also has a complement system. This work will help to improve our understanding of the innate immune system in these spiders and the ancestral structure of C3.
Keywords
ORFThioester-containing proteinsLoxoscelesTEDTEPCR2CR3CR1A2MAnaphylatoxinESTANAphylogenetic analysisExpressed Sequence TagComplement C3Maximum likelihoodComplement systemMuscleSPIDERFactor BFactor Hopen reading frameMacroglobulinAlpha-2 macroglobulinmultiple sequence comparison by log-expectationGeneComplement receptor 3complement receptor 1complement receptor 2
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Authors
D.T. Myamoto, G. Pidde-Queiroz, A. Pedroso, R.M. Gonçalves-de-Andrade, C.W. van den Berg, D.V. Tambourgi,