title: The protozoa dinoflagellate Oxyrrhis marina contains selenoproteins and the relevant translation apparatus.
abstract: In the phylogenetic tree, selenoproteins and the corresponding translation machinery are found in Archaea, Eubacteria, and animals, but not in fungi and higher plants. As very little is known about Protozoa, we searched for the presence of selenoproteins in the primitive dinoflagellate Oxyrrhis marina, belonging to the Protoctista kingdom. Four selenoproteins could be obtained from O. marina cells cultured in the presence of 75Se. Using O. marina or bovine liver cytosolic extracts, we could serylate and selenylate in vitro total O. marina tRNAs. Moreover, the existence of a tRNA(Sec) could be deduced from in vivo experiments. Lastly, an anti-serum against the specialized mammalian translation elongation factor mSelB reacted with a protein of 48-kDa molecular mass. Altogether, our data showed that O. marina contains selenoproteins and suggests that the corresponding translation machinery is related to that found in animals.
authors.affiliation: Graduate School of Pharmaceutical Sciences, Nagoya City University, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Osaka
authors.forename: Asa
authors.initials: A
authors.lastname: Beika
authors.forename: Asuka
authors.initials: A
authors.lastname: Hattori
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Kohno
authors.forename: Koichi H
authors.initials: KH
authors.lastname: Kato
authors.forename: Takaharu
authors.initials: T
authors.lastname: Mizutani
mesh_terms: D000818:Animals; D002417:Cattle; D004141:Dinoflagellida / Q000235:genetics* / Q000378:metabolism*; D066298:In Vitro Techniques; D014176:Protein Biosynthesis; D011506:Proteins / Q000235:genetics* / Q000378:metabolism*; D016053:RNA, Protozoan / Q000235:genetics / Q000378:metabolism; D012346:RNA, Transfer, Amino Acyl / Q000235:genetics / Q000378:metabolism; D017279:Selenocysteine / Q000378:metabolism; D051140:Selenoproteins
chemical_list: D011506:Proteins; D016053:RNA, Protozoan; D012346:RNA, Transfer, Amino Acyl; D051140:Selenoproteins; C112705:selenocysteinyl-tRNA; D017279:Selenocysteine