title: Cellular localization of mitotic RAD21 with repetitive amino acid motifs in Allium cepa.
abstract: Onion can be used in experimental observation of mitotic cell division in plant science because its chromosome is large and easy to observe. However, molecular genetic studies are difficult in onion because of its large genome size, and only limited information of onion genes has been available to date. Here we cloned and characterized an onion homologue of mitotic RAD21 gene, AcRAD21-1, to develop a molecular marker of mitosis. The N-terminal, middle, and C-terminal regions of deduced AcRAD21-1 protein sequence were conserved with Arabidopsis SYN4/AtRAD21.3 and rice OsRAD21-1, whereas three characteristic types of repetitive motifs (Repeat-1, Repeat-2/2', and Repeat-3) were observed between the conserved regions. Such inserted repetitive amino acid sequences enlarge the AcRAD21-1 protein into almost 200 kDa, which belongs to the largest class of plant proteins. Genomic organization of the AcRAD21-1 locus was also determined, and the possibility of tandem exon duplication in Repeat-2 was revealed. Subsequently, the polyclonal antiserum was raised against the N-terminal region of AcRAD21-1, and purified by affinity chromatography. Immunohistochemical analysis with the purified antibody successfully showed localization of AcRAD21-1 in onion mitosis, suggesting that it can be used as a molecular marker visualizing dynamic movement of cohesin.
authors.affiliation: Division of Natural Science, Osaka Kyoiku University, 4-698-1 Asahigaoka, Kashiwara, Osaka 582-8582, Japan. gsuzuki@cc.osaka-kyoiku.ac.jp
authors.forename: Go
authors.initials: G
authors.lastname: Suzuki
authors.forename: Chikage
authors.initials: C
authors.lastname: Nishiuchi
authors.forename: Asami
authors.initials: A
authors.lastname: Tsuru
authors.forename: Eri
authors.initials: E
authors.lastname: Kako
authors.forename: Jian
authors.initials: J
authors.lastname: Li
authors.forename: Maki
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Mukai
mesh_terms: D020816:Amino Acid Motifs / Q000235:genetics; D000595:Amino Acid Sequence; D001483:Base Sequence; D015153:Blotting, Western; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D003001:Cloning, Molecular; D005091:Exons / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D007438:Introns / Q000235:genetics; D008938:Mitosis / Q000235:genetics*; D008969:Molecular Sequence Data; D019697:Onions / Q000166:cytology / Q000235:genetics* / Q000378:metabolism; D010802:Phylogeny; D010940:Plant Proteins / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D018520:Plant Shoots / Q000235:genetics / Q000378:metabolism; D020449:Repetitive Sequences, Amino Acid / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
chemical_list: D018797:Cell Cycle Proteins; D010940:Plant Proteins