%0 Journal Article
%T Eukaryotic Signature Proteins - Eukaryotic Signature Proteins - Open Access Pub
%A Jian Han
%A Lesley J. Collins
%J OAP | Home | Journal of Proteomics and Genomics Research | Open Access Pub
%D 2018
%X Eukaryotic Signature Proteins (ESPs) are proteins that delineate the eukaryotes from the archaea and bacteria. They have no recognisable homologues in any prokaryotic genome, but their homologues are present in all main branches of eukaryotes. ESPs are thus likely to have descended from ancient proteins that have existed since the first eukaryotic cell. The last dataset of ESPs was calculated more than a decade ago, thus with advances in technology and the rapid completion of many evolutionary important genomes, this dataset required recalculating. This study recalculated the Giardia lamblia ESP dataset and provides a procedure to calculate signature proteins beginning with any species. The G. lamblia ESP dataset contained a range of proteins including many associated with the membrane, cytoskeleton, nucleus and protein synthesis. ESP datasets have implications on current models of eukaryotic evolution, having high importance in phylogenetic analysis due to ESPsĄŻ consistency and conservation in all eukaryotic species. DOI10.14302/issn.2326-0793.jpgr-12-101 Eukaryotic Signature Proteins Eukaryotes are remarkably different from prokaryotes (archaea and bacteria), in terms of cellular structure, genetic content and proteome. Finding a set of proteins which can delineate eukaryotes from prokaryotes can be crucial to understanding the major differences in metabolism between the two groups. Eukaryotic signature proteins (ESPs) are such proteins, since by definition they have no recognisable homologues in prokaryotic genomes, but their homologues are present in all the main branches of eukaryotes. They are involved in most core functions of a eukaryote and provide landmarks to track the origin and evolution of eukaryotic genomes 1. The approach of searching for signature proteins was first used by Graham et al. in searching for archaeal signature proteins 2. Their study in 1999 found 351 clusters of proteins found only in Euryarchaeota species. Hartman and Fedorov 3 then focused on eukaryotes collecting ESPs by searching yeast protein homologues against three kingdoms of life (archaea, bacteria and eukaryotes). Their analysis procedure began with the Saccharomyces cerevisiae genome removing proteins without homologues in Caenorhabditis elegans, Drosophila melanogaster and Arabidopsis thaliana. After that, proteins that have homologues in any of the 44 bacterial and archaeal species (the only available complete bacterial and archaeal genomes at the time) were removed. Lastly they removed proteins without homologues in Giardia lamblia (from here on Giardia)3. By
%U https://www.openaccesspub.org/jpgr/article/18