title: Characterization of TSET, an ancient and widespread membrane trafficking complex.
abstract: The heterotetrameric AP and F-COPI complexes help to define the cellular map of modern eukaryotes. To search for related machinery, we developed a structure-based bioinformatics tool, and identified the core subunits of TSET, a 'missing link' between the APs and COPI. Studies in Dictyostelium indicate that TSET is a heterohexamer, with two associated scaffolding proteins. TSET is non-essential in Dictyostelium, but may act in plasma membrane turnover, and is essentially identical to the recently described TPLATE complex, TPC. However, whereas TPC was reported to be plant-specific, we can identify a full or partial complex in every eukaryotic supergroup. An evolutionary path can be deduced from the earliest origins of the heterotetramer/scaffold coat to its multiple manifestations in modern organisms, including the mammalian muniscins, descendants of the TSET medium subunits. Thus, we have uncovered the machinery for an ancient and widespread pathway, which provides new insights into early eukaryotic evolution.DOI: http://dx.doi.org/10.7554/eLife.02866.001.
authors.affiliation: Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom jh228@cam.ac.uk.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Hirst
authors.affiliation: Department of Cell Biology, University of Alberta, Edmonton, Canada.
authors.forename: Alexander
authors.initials: A
authors.lastname: Schlacht
authors.affiliation: Department of Engineering, University of Cambridge, Cambridge, United Kingdom.
authors.forename: John P
authors.initials: JP
authors.lastname: Norcott
authors.affiliation: Cell Biology, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom.
authors.forename: David
authors.initials: D
authors.lastname: Traynor
authors.affiliation: Cell Biology, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom.
authors.forename: Gareth
authors.initials: G
authors.lastname: Bloomfield
authors.affiliation: Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Robin
authors.initials: R
authors.lastname: Antrobus
authors.affiliation: Cell Biology, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom.
authors.forename: Robert R
authors.initials: RR
authors.lastname: Kay
authors.affiliation: Department of Cell Biology, University of Alberta, Edmonton, Canada dacks@ualberta.ca.
authors.forename: Joel B
authors.initials: JB
authors.lastname: Dacks
authors.affiliation: Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom msr12@cam.ac.uk.
authors.forename: Margaret S
authors.initials: MS
authors.lastname: Robinson
mesh_terms: D017360:Arabidopsis / Q000235:genetics; D002462:Cell Membrane / Q000378:metabolism; D019295:Computational Biology; D030541:Databases, Genetic; D004023:Dictyostelium / Q000235:genetics* / Q000378:metabolism; D019143:Evolution, Molecular; D005786:Gene Expression Regulation; D023281:Genomics; D009253:Naegleria / Q000235:genetics; D010802:Phylogeny; D011487:Protein Conformation; D021381:Protein Transport; D040901:Proteomics; D015800:Protozoan Proteins / Q000235:genetics* / Q000378:metabolism; D017422:Sequence Analysis, DNA
chemical_list: D015800:Protozoan Proteins
keywords: FCHo; TPC; TPLATE; clathrin; membrane traffic; muniscin