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Early Vertebrate Evolution of the Host Restriction Factor Tetherin
Elena Heusinger1, Silvia F Kluge1, Frank Kirchhoff1
1Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany.
Journal of Virology
|September 25, 2015
Summary
Tetherin, an antiviral protein, emerged over 450 million years ago in early vertebrates. This ancient restriction factor, found in fish, reptiles, and birds, predates mammals and effectively blocks viral release.
Area of Science:
- * Virology
- * Evolutionary Biology
- * Immunology
Background:
- * Tetherin is an interferon-inducible protein that restricts enveloped virus release.
- * Its unique structure involves two membrane anchors, bridging viral and cellular membranes.
- * Previously, only mammalian tetherin orthologs were known, leaving its evolutionary origins unclear.
Purpose of the Study:
- * To investigate the evolutionary history and distribution of tetherin.
- * To determine if tetherin's antiviral activity predates mammalian divergence.
- * To explore the conservation of tetherin's unique topology across species.
Main Methods:
- * Comparative genomic analysis of vertebrate genomes to identify tetherin orthologs.
- * Functional assays using alligator tetherin to assess its ability to inhibit retroviral particle release.
- * Examination of non-vertebrate proteins with similar topological features.
Main Results:
- * Tetherin orthologs were identified in fish, reptiles, and birds, indicating an ancient origin.
- * Alligator tetherin demonstrated potent inhibition of retroviral particle release.
- * Conserved topology was observed across orthologs, despite limited sequence homology.
Conclusions:
- * Tetherin is an ancient antiviral restriction factor, present in vertebrates for at least 450 million years.
- * Its antiviral function evolved early, before the divergence of mammals and reptiles.
- * The conserved topology suggests a primary role in restricting virus release, conserved across diverse species.
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