title: Gene fusion, fission, lateral transfer, and loss: Not-so-rare events in the evolution of eukaryotic ATP citrate lyase.
abstract: ATP citrate lyase (ACL) is an enzyme critical to the generation of cytosolic acetyl-CoA in eukaryotes. In most studied organisms, ACL activity is conferred in combination by two proteins, ACLA and ACLB (dsACL); however, animals encode a single-subunit ACL (ssACL) - the result of a gene fusion event. Through phylogenetic analyses, we investigated the evolution of ACL in a broad range of eukaryotes, including numerous microbes (protists). We show that the fused form is not restricted to animals, and is instead widely distributed among eukaryotes. Furthermore, ssACL and dsACL are patchily distributed and appear to be mutually exclusive; both types arose early in eukaryotic evolution. Finally, we present several compelling hypotheses of lateral gene transfer and gene loss, along with the secondary gene fission of ssACL in Ascomycota. Collectively, our in-depth analyses suggest that a complex suite of evolutionary events, usually considered rare, has shaped the evolution of ACL in eukaryotes.
authors.affiliation: Centre for Comparative Genomics and Evolutionary Bioinformatics, Department of Biochemistry and Molecular Biology, Dalhousie University, 5850 College Street, Halifax, Nova Scotia B3H 4R2, Canada.
authors.forename: Ryan M R
authors.initials: RM
authors.lastname: Gawryluk
authors.affiliation: Centre for Comparative Genomics and Evolutionary Bioinformatics, Department of Biochemistry and Molecular Biology, Dalhousie University, 5850 College Street, Halifax, Nova Scotia B3H 4R2, Canada.
authors.forename: Laura
authors.initials: L
authors.lastname: Eme
authors.affiliation: Centre for Comparative Genomics and Evolutionary Bioinformatics, Department of Biochemistry and Molecular Biology, Dalhousie University, 5850 College Street, Halifax, Nova Scotia B3H 4R2, Canada. Electronic address: andrew.roger@dal.ca.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Roger
mesh_terms: D001275:ATP Citrate (pro-S)-Lyase / Q000145:classification / Q000235:genetics*; D000818:Animals; D056890:Eukaryota / Q000201:enzymology / Q000235:genetics*; D019143:Evolution, Molecular; D017353:Gene Deletion; D050939:Gene Fusion; D022761:Gene Transfer, Horizontal; D010802:Phylogeny
chemical_list: D001275:ATP Citrate (pro-S)-Lyase
keywords: ATP citrate lyase; Eukaryotic evolution; Gene fission; Gene fusion; Lateral gene transfer; Protist