title: RING finger, B-box, and coiled-coil (RBCC) protein expression in branchial epithelial cells of Japanese eel, Anguilla japonica.
abstract: An RBCC (RING finger, B-box, and coiled-coil) protein was identified that belongs to the superfamily of zinc-binding proteins and is specifically expressed in the gill of eel, Anguilla japonica. Euryhaline fishes such as eels can migrate between freshwater and seawater, which is considered to be accomplished by efficient remodeling of the architecture and function of the gill, a major osmoregulatory organ. To identify molecules involved in such adaptive changes, we performed differential display using mRNA preparations from freshwater and seawater eel gills and obtained an RBCC clone among several differentially expressed clones. The clone encoded a protein of 514 amino acid residues with structural features characteristic of the RBCC protein; we therefore named it eRBCC (e for eel). eRBCC mRNA was specifically expressed in the gills with a greater extent in the gills of freshwater eels. Immunohistochemistry revealed that the expression of eRBCC is confined to particular epithelial cells of the gills including freshwater-specific lamellar chloride cells. The RING finger of eRBCC was found to have a ubiquitin ligase activity, suggesting an important regulatory role of eRBCC in the remodeling of branchial cells.
authors.affiliation: Department of Biological Sciences, Tokyo Institute of Technology, Yokohama, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Miyamoto
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Nakamura
authors.forename: Masahide
authors.initials: M
authors.lastname: Kashiwagi
authors.forename: Shinji
authors.initials: S
authors.lastname: Honda
authors.forename: Akira
authors.initials: A
authors.lastname: Kato
authors.forename: Sanae
authors.initials: S
authors.lastname: Hasegawa
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Takei
authors.forename: Shigehisa
authors.initials: S
authors.lastname: Hirose
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D015153:Blotting, Western; D019556:COS Cells; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000378:metabolism; D004524:Eels / Q000235:genetics* / Q000378:metabolism; D004847:Epithelial Cells; D020869:Gene Expression Profiling; D005880:Gills / Q000378:metabolism; D007150:Immunohistochemistry; D008025:Ligases / Q000096:biosynthesis* / Q000737:chemistry* / Q000378:metabolism; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000378:metabolism; D012260:Ribonucleases / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013997:Time Factors; D014018:Tissue Distribution; D025801:Ubiquitin / Q000378:metabolism; D016335:Zinc Fingers
chemical_list: D018076:DNA, Complementary; D012333:RNA, Messenger; D025801:Ubiquitin; D012260:Ribonucleases; D008025:Ligases