title: Ancient, highly conserved proteins from a LUCA with complex cell biology provide evidence in support of the nuclear compartment commonality (NuCom) hypothesis.
abstract: The nuclear compartment commonality (NuCom) hypothesis posits a complex last common ancestor (LUCA) with membranous compartments including a nuclear membrane. Such a LUCA then evolved to produce two nucleated lineages of the tree of life: the Planctomycetes-Verrucomicrobia-Chlamydia superphylum (PVC) within the Bacteria, and the Eukarya. We propose that a group of ancient essential protokaryotic signature proteins (PSPs) originating in LUCA were incorporated into ancestors of PVC Bacteria and Eukarya. Tubulins, ubiquitin system enzymes and sterol-synthesizing enzymes are consistent with early origins of these features shared between the PVC superphylum and Eukarya.
authors.affiliation: Department of Microbiology and Astrobiology Program, University of Washington, Seattle 98195, USA.
authors.forename: James T
authors.initials: JT
authors.lastname: Staley
authors.affiliation: School of Chemistry and Molecular Biosciences, University of Queensland, St. Lucia, Queensland 4072, Australia. Electronic address: j.fuerst@uq.edu.au.
authors.forename: John A
authors.initials: JA
authors.lastname: Fuerst
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism; D002451:Cell Compartmentation / Q000235:genetics*; D002689:Chlamydia / Q000235:genetics; D056890:Eukaryota / Q000235:genetics; D019143:Evolution, Molecular; D009685:Nuclear Envelope; D010802:Phylogeny; D014404:Tubulin / Q000235:genetics / Q000378:metabolism; D025801:Ubiquitin / Q000235:genetics / Q000378:metabolism; D061327:Verrucomicrobia / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D014404:Tubulin; D025801:Ubiquitin
keywords: Ancient cell compartmentalization; LUCA; Origin of eukaryotes; PVC superphylum; Planctomycetes; Verrucomicrobia