title: Mitochondrial-nuclear co-evolution leads to hybrid incompatibility through pentatricopeptide repeat proteins.
abstract: Mitochondrial-nuclear incompatibility has a major role in reproductive isolation between species. However, the underlying mechanism and driving force of mitochondrial-nuclear incompatibility remain elusive. Here, we report a pentatricopeptide repeat-containing (PPR) protein, Ccm1, and its interacting partner, 15S rRNA, to be involved in hybrid incompatibility between two yeast species, Saccharomyces cerevisiae and Saccharomyces bayanus S. bayanus-Ccm1 has reduced binding affinity for S. cerevisiae-15S rRNA, leading to respiratory defects in hybrid cells. This incompatibility can be rescued by single mutations on several individual PPR motifs, demonstrating the highly evolvable nature of PPR proteins. When we examined other PPR proteins in the closely related Saccharomyces sensu stricto yeasts, about two-thirds of them showed detectable incompatibility. Our results suggest that fast co-evolution between flexible PPR proteins and their mitochondrial RNA substrates may be a common driving force in the development of mitochondrial-nuclear hybrid incompatibility.
authors.affiliation: Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan.|Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan.
authors.forename: Han-Ying
authors.identifier: 0000-0002-1918-5151
authors.initials: HY
authors.lastname: Jhuang
authors.affiliation: Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan.|Molecular and Cell Biology, Taiwan International Graduate Program, Graduate Institute of Life Sciences, National Defense Medical Center and Academia Sinica, Taipei, Taiwan.
authors.forename: Hsin-Yi
authors.initials: HY
authors.lastname: Lee
authors.affiliation: Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan jleu@imb.sinica.edu.tw.|Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan.
authors.forename: Jun-Yi
authors.identifier: 0000-0001-5445-2799
authors.initials: JY
authors.lastname: Leu
mesh_terms: D000595:Amino Acid Sequence; D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism*; D015825:Chromosomes, Fungal; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016681:Genome, Fungal; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D009154:Mutation; D010455:Peptides; D011485:Protein Binding; D011487:Protein Conformation; D054730:Protein Interaction Domains and Motifs; D012313:RNA; D000077278:RNA, Mitochondrial; D012335:RNA, Ribosomal; D012091:Repetitive Sequences, Nucleic Acid
chemical_list: D005656:Fungal Proteins; D024101:Mitochondrial Proteins; D010455:Peptides; D000077278:RNA, Mitochondrial; D012335:RNA, Ribosomal; D012313:RNA
keywords: PPR protein; hybrid incompatibility; mitochondrial–nuclear co‐evolution; yeast speciation