Abstract
The ubiquitously expressed 14-3-3 family of proteins is evolutionary conserved from yeast to mammals. Their involvement in humoral and cellular immune responses is emerging through studies in drosophila and humans. In humans, a select group of 14-3-3 isoforms are antigenic; however the determinants of their antigenicity are not known. Here, we show that although mammalian 14-3-3 proteins are mostly conserved, subtle differences between their isoforms may give rise to their antigenicity. We observed syntenic relations among all the isoforms of 14-3-3 for mammals, but not with that of birds or amphibians. However, the parasitic 14-3-3 isoforms, which have known antigenic properties, show unique sequence, structure and evolution compared to the human 14-3-3. Moreover we report, for the first time the existence of a bacterial 14-3-3 protein. Contrary to the parasitic isoforms, both bacterial and yeast 14-3-3 exhibited significant homology with mammalian 14-3-3 in protein sequence as well as structure. Furthermore, a human 14-3-3 inhibitor caused significant killing of Candida albicans, which could be due to the inhibition of the structurally similar yeast homologue of 14-3-3, BMH, which is essential for its life cycle. Overall, our bioinformatic analysis combined with the demonstration of a novel antifungal role of a peptide inhibitor of human 14-3-3 indicates that the sequences and structural similarities between the mammalian, bacterial and fungal proteins are likely determinants of the antigenic nature of these proteins. Further, we propose that molecular mimicry triggered by microbial infections with either yeast or bacteria may contribute to the antigenic role of human 14-3-3.
Original language | English |
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Article number | e0189503 |
Journal | PLoS ONE |
Volume | 12 |
Issue number | 12 |
DOIs | |
State | Published - Dec 2017 |
Bibliographical note
Publisher Copyright:© 2017 McGowan et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
ASJC Scopus subject areas
- General Biochemistry, Genetics and Molecular Biology
- General Agricultural and Biological Sciences
- General