title: Localization and Evolution of Putative Triose Phosphate Translocators in the Diatom Phaeodactylum tricornutum.
abstract: The establishment of a metabolic connection between host and symbiont is a crucial step in the evolution of an obligate endosymbiotic relationship. Such was the case in the evolution of mitochondria and plastids. Whereas the mechanisms of metabolite shuttling between the plastid and host cytosol are relatively well studied in Archaeplastida-organisms that acquired photosynthesis through primary endosymbiosis-little is known about this process in organisms with complex plastids. Here, we focus on the presence, localization, and phylogeny of putative triose phosphate translocators (TPTs) in the complex plastid of diatoms. These proteins are thought to play an essential role in connecting endosymbiont and host metabolism via transport of carbohydrates generated by the photosynthesis machinery of the endosymbiont. We show that the complex plastid localized TPTs are monophyletic and present a model for how the initial metabolic link between host and endosymbiont might have been established in diatoms and other algae with complex red plastids and discuss its implications on the evolution of those lineages.
authors.affiliation: LOEWE Centre for Synthetic Microbiology (SYNMIKRO), Philipps University Marburg, Germany Present address: Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada.
authors.forename: Daniel
authors.initials: D
authors.lastname: Moog
authors.affiliation: Plant Cell Biology, Philipps University Marburg, Germany.
authors.forename: Stefan A
authors.initials: SA
authors.lastname: Rensing
authors.affiliation: Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada Program in Integrated Microbial Biodiversity, Canadian Institute for Advanced Research, Toronto, Ontario, Canada.
authors.forename: John M
authors.initials: JM
authors.lastname: Archibald
authors.affiliation: LOEWE Centre for Synthetic Microbiology (SYNMIKRO), Philipps University Marburg, Germany Laboratory for Cell Biology, Philipps University Marburg, Germany maier@biologie.uni-marburg.de.
authors.forename: Uwe G
authors.initials: UG
authors.lastname: Maier
authors.affiliation: Plant Cell Biology, Philipps University Marburg, Germany.
authors.forename: Kristian K
authors.initials: KK
authors.lastname: Ullrich
mesh_terms: D000595:Amino Acid Sequence; D005075:Biological Evolution; D060365:Chloroplast Proteins / Q000235:genetics*; D017377:Diatoms / Q000235:genetics*; D008969:Molecular Sequence Data; D009004:Monosaccharide Transport Proteins / Q000235:genetics*; D010710:Phosphates / Q000378:metabolism; D010802:Phylogeny; D018087:Plastids / Q000235:genetics; D013559:Symbiosis; D014306:Trioses / Q000378:metabolism
chemical_list: D060365:Chloroplast Proteins; D009004:Monosaccharide Transport Proteins; D010710:Phosphates; D014306:Trioses
keywords: complex plastid; diatoms; metabolic coupling; protein targeting; secondary endosymbiosis