title: Proteomics analysis of heterogeneous flagella in brown algae (stramenopiles).
abstract: Flagella are conserved organelles among eukaryotes and they are composed of many proteins, which are necessary for flagellar assembly, maintenance and function. Stramenopiles, which include brown algae, diatoms and oomycetes, possess two laterally inserted flagella. The anterior flagellum (AF) extends forward and bears tripartite mastigonemes, whilst the smooth posterior flagellum (PF) often has a paraflagellar body structure. These heterogeneous flagella have served as crucial structures in algal studies especially from a viewpoint of phylogeny. However, the protein compositions of the flagella are still largely unknown. Here we report a LC-MS/MS based proteomics analysis of brown algal flagella. In total, 495 flagellar proteins were identified. Functional annotation of the proteome data revealed that brown algal flagellar proteins were associated with cell motility, signal transduction and various metabolic activities. We separately isolated AF and PF and analyzed their protein compositions. This analysis led to the identification of several AF- and PF-specific proteins. Among the PF-specific proteins, we found a candidate novel blue light receptor protein involved in phototaxis, and named it HELMCHROME because of the steering function of PF. Immunological analysis revealed that this protein was localized along the whole length of the PF and concentrated in the paraflagellar body.
authors.affiliation: Muroran Marine Station, Field Science Center for Northern Biosphere, Hokkaido University, Muroran 051-0013, Hokkaido, Japan.
authors.forename: Gang
authors.initials: G
authors.lastname: Fu
authors.affiliation: Muroran Marine Station, Field Science Center for Northern Biosphere, Hokkaido University, Muroran 051-0013, Hokkaido, Japan.
authors.forename: Chikako
authors.initials: C
authors.lastname: Nagasato
authors.affiliation: Instrumental Analysis Division, Equipment Management Center, Creative Research Institution, Hokkaido University, Sapporo 001-0021, Hokkaido, Japan.
authors.forename: Seiko
authors.initials: S
authors.lastname: Oka
authors.affiliation: University Pierre et Marie Curie and Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7139, Laboratoire International Associé Dispersal and Adaptation in Marine Species, Station Biologique de Roscoff, 29682 Roscoff Cedex, France.
authors.forename: J Mark
authors.initials: JM
authors.lastname: Cock
authors.affiliation: Muroran Marine Station, Field Science Center for Northern Biosphere, Hokkaido University, Muroran 051-0013, Hokkaido, Japan. Electronic address: motomura@fsc.hokudai.ac.jp.
authors.forename: Taizo
authors.initials: T
authors.lastname: Motomura
mesh_terms: D020418:Algal Proteins / Q000032:analysis*; D002853:Chromatography, Liquid; D005407:Flagella / Q000737:chemistry*; D000459:Phaeophyceae / Q000737:chemistry*; D020543:Proteome / Q000032:analysis*; D040901:Proteomics; D053719:Tandem Mass Spectrometry
chemical_list: D020418:Algal Proteins; D020543:Proteome
keywords: Blue light receptor; brown algae; creatine kinase; flagella; phototaxis; proteomics.