Ticks from diverse genera encode chemokine-inhibitory evasin proteins

Hayward, Jenni; Sanchez, Julie; Perry, Andrew; Huang, Cheng; Rodriguez Valle, Manuel; Canals, Meritxell; Payne, Richard J.; Stone, Martin J.

Abstract

To prolong residence on their hosts, ticks secrete many salivary factors that target host defense molecules. In particular, the tick Rhipicephalus sanguineus has been shown to produce three salivary glycoproteins named “evasins,” which bind to host chemokines, thereby inhibiting the recruitment of leukocytes to the location of the tick bite. Using sequence similarity searches, we have identified 257 new putative evasin sequences encoded by the genomes or salivary or visceral transcriptomes of numerous hard ticks, spanning the genera Rhipicephalus, Amblyomma, and Ixodes of the Ixodidae family. Nine representative sequences were successfully expressed in Escherichia coli, and eight of the nine candidates exhibited high-affinity binding to human chemokines. Sequence alignments enabled classification of the evasins into two subfamilies: C8 evasins share a conserved set of eight Cys residues (four disulfide bonds), whereas C6 evasins have only three of these disulfide bonds. Most of the identified sequences contain predicted secretion leader sequences, N-linked glycosylation sites, and a putative site of tyrosine sulfation. We conclude that chemokine-binding evasin proteins are widely expressed among tick species of the Ixodidae family, are likely to play important roles in subverting host defenses, and constitute a valuable pool of anti-inflammatory proteins for potential future therapeutic applications. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Citation

Hayward, J., Sanchez, J., Perry, A., Huang, C., Rodriguez Valle, M., Canals, M., …Stone, M. J. (2017). Ticks from diverse genera encode chemokine-inhibitory evasin proteins. Journal of Biological Chemistry, 292(38), 15670-15680. https://doi.org/10.1074/jbc.M117.807255

• Journal Article Type: Article
• Acceptance Date: Aug 4, 2017
• Online Publication Date: Aug 4, 2017
• Publication Date: Sep 22, 2017
• Deposit Date: Jan 17, 2020
• Journal: Journal of Biological Chemistry
• Print ISSN: 0021-9258
• Electronic ISSN: 1083-351X
• Publisher: American Society for Biochemistry and Molecular Biology
• Peer Reviewed: Peer Reviewed
• Volume: 292
• Issue: 38
• Pages: 15670-15680
• DOI: https://doi.org/10.1074/jbc.M117.807255
• Keywords: Amino acids; Bins; Covalent bonds; Escherichia coli; Peptides; Anti-inflammatory proteins; Disulfide bonds; High affinity binding; N-linked glycosylation; Rhipicephalus sanguineus; Sequence alignments; Sequence similarity; Therapeutic Application; Protein
• Public URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85029755774&doi=10.1074%2fjbc.M117.807255&partnerID=40&md5=ca4c94f0f8a9d955b49b6ee9b6bc3fac