title: A Ribbon-like Structure in the Ejective Organelle of the Green Microalga Pyramimonas parkeae (Prasinophyceae) Consists of Core Histones and Polymers Containing N-acetyl-glucosamine.
abstract: The green microalga, Pyramimonas parkeae (Prasinophyceae) has an ejective organelle containing a coiled ribbon structure resembling the ejectisome in Cryptophyta. This structure is discharged from the cell by a stimulus and extends to form a tube-like structure, but the molecular components of the structure have not been identified. Tricine-SDS-PAGE analysis indicated that the ribbon-like structure of P. parkeae contains some proteins and low molecular acidic polymers. Edman degradation, LC/MS/MS analyses and immunological studies demonstrated that their proteins are core histones (H3, H2A, H2B and H4). In addition, monosaccharide composition analysis of the ribbon-like structures and degradation by lysozyme strongly indicated that the ribbon-like structure consist of β (1-4) linked polymers containing N-acetyl-glucosamine. Purified polymers and recombinant histones formed glob-like or filamentous structures. Therefore we conclude that the ribbon-like structure of P. parkeae mainly consists of a complex of core histones (H3, H2A, H2B and H4) and polymers containing N-acetyl-glucosamine, and suggest to name the ejective organelle in P. parkeae the "histrosome" to distinguish it from the ejectisome in Cryptophyta.
authors.affiliation: Research Center for Inland Seas, Kobe University, Rokkodai 1-1, Kobe 657-8501, Japan. Electronic address: yamataka312@gmail.com.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Yamagishi
authors.affiliation: Faculty of Agriculture, Kyushu University, Fukuoka 812-8581, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Kurihara
authors.affiliation: Research Center for Inland Seas, Kobe University, Rokkodai 1-1, Kobe 657-8501, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kawai
mesh_terms: D000117:Acetylglucosamine / Q000378:metabolism*; D020418:Algal Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D000460:Chlorophyta / Q000235:genetics* / Q000378:metabolism; D006657:Histones / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D015388:Organelles / Q000378:metabolism; D010802:Phylogeny; D011108:Polymers / Q000378:metabolism; D017422:Sequence Analysis, DNA
chemical_list: D020418:Algal Proteins; D006657:Histones; D011108:Polymers; D000117:Acetylglucosamine
keywords: Core histone; N-acetyl-glucosamine; Pyramimonas parkeae.; ejectisome