tRNA genes rapidly change in evolution to meet novel translational demands
Avihu H Yona,
Zohar Bloom-Ackermann,
Idan Frumkin,
Victor Hanson-Smith,
Yoav Charpak-Amikam,
Qinghua Feng,
Jef D Boeke,
Orna Dahan,
Yitzhak Pilpel
Affiliations
Avihu H Yona
Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
Zohar Bloom-Ackermann
Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
Idan Frumkin
Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
Victor Hanson-Smith
Department of Microbiology, University of California, San Francisco, San Francisco, United States; Department of Immunology, University of California, San Francisco, San Francisco, United States
Yoav Charpak-Amikam
Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
Qinghua Feng
Department of Pathology, University of Washington, Seattle, United States
Jef D Boeke
Department of Molecular Biology and Genetics, The Johns Hopkins University School of Medicine, Baltimore, United States
Orna Dahan
Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
Yitzhak Pilpel
Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
Changes in expression patterns may occur when organisms are presented with new environmental challenges, for example following migration or genetic changes. To elucidate the mechanisms by which the translational machinery adapts to such changes, we perturbed the tRNA pool of Saccharomyces cerevisiae by tRNA gene deletion. We then evolved the deletion strain and observed that the genetic adaptation was recurrently based on a strategic mutation that changed the anticodon of other tRNA genes to match that of the deleted one. Strikingly, a systematic search in hundreds of genomes revealed that anticodon mutations occur throughout the tree of life. We further show that the evolution of the tRNA pool also depends on the need to properly couple translation to protein folding. Together, our observations shed light on the evolution of the tRNA pool, demonstrating that mutation in the anticodons of tRNA genes is a common adaptive mechanism when meeting new translational demands.
