Highly dynamic exon shuffling in candidate pathogen receptors ... What if brown algae were capable of adaptive immunity?
Zambounis, A.; Elias, M.; Sterck, L.; Maumus, F.; Gachon, C.M.M. (2012). Highly dynamic exon shuffling in candidate pathogen receptors ... What if brown algae were capable of adaptive immunity? Mol. Biol. Evol. 29(4): 1263-1276. https://dx.doi.org/10.1093/molbev/msr296 In: Molecular Biology and Evolution. Oxford University Press: Chicago, Ill.. ISSN 0737-4038; e-ISSN 1537-1719, more |   |
| Keywords | Marine Sciences
Marine Sciences > Marine Genomics
Scientific Community
Scientific Publication
Ectocarpus Lyngbye, 1819 [WoRMS]
Marine/Coastal | | Author keywords | brown alga; Ectocarpus; exon shuffling; resistance gene analogue; innateimmunity; adaptive immunity |
| Project | Top | Authors | - Association of European marine biological laboratories, more
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| Authors | | Top | - Zambounis, A.
- Elias, M.
- Sterck, L., more
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| Abstract | Pathogen recognition is the first step of immune reactions. In animals and plants, direct or indirect pathogen recognition is often mediated by a wealth of fast-evolving receptors, many of which contain ligand-binding and signal transduction domains, such as leucine-rich or tetratricopeptide repeat (LRR/TPR) and NB-ARC domains, respectively. In order to identify candidates potentially involved in algal defense, we mined the genome of the brown alga Ectocarpus siliculosus for homologues of these genes and assessed the evolutionary pressures acting upon them. We thus annotated all Ectocarpus LRR-containing genes, in particular an original group of LRR-containing GTPases of the ROCO family, and 24 NB-ARC–TPR proteins. They exhibit high birth and death rates, while a diversifying selection is acting on their LRR (respectively TPR) domain, probably affecting the ligand-binding specificities. Remarkably, each repeat is encoded by an exon, and the intense exon shuffling underpins the variability of LRR and TPR domains. We conclude that the Ectocarpus ROCO and NB-ARC–TPR families are excellent candidates for being involved in recognition/transduction events linked to immunity. We further hypothesize that brown algae may generate their immune repertoire via controlled somatic recombination, so far only known from the vertebrate adaptive immune systems. |
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