title: Identification of testis-specific ubiquitin-conjugating enzyme in the ascidian Ciona intestinalis.
abstract: The ubiquitin-proteasome system is known to play a key role in fertilization in ascidians, sea urchins, and mammals. To obtain insights into the ubiquitin-conjugating enzymes (Ube2) involved in reproductive systems, we systematically explored Ube2 enzymes expressed in the testis of the ascidian Ciona intestinalis. Here, we report cDNA cloning and characterization of a novel type of Ube2r (Ci0100152677) that is capable of making a thiolester bond with ubiquitin. Northern analysis, whole-mount in situ hybridization and immunocytochemistry indicate that this enzyme is exclusively expressed in the testis, mainly in the germ cells during the late stage of spermatogenesis, and is localized in the sperm head and tail, suggesting possible participation in fertilization or spermatogenesis/spermiogenesis.
authors.affiliation: Sugashima Marine Biological Laboratory, Graduate School of Science, Nagoya University, Toba, Japan.
authors.forename: Naoto
authors.initials: N
authors.lastname: Yokota
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Harada
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Sawada
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002938:Ciona intestinalis / Q000201:enzymology* / Q000378:metabolism; D016000:Cluster Analysis; D004591:Electrophoresis, Polyacrylamide Gel; D004952:Esters / Q000378:metabolism; D020224:Expressed Sequence Tags; D005455:Fluorescent Antibody Technique; D020869:Gene Expression Profiling; D008297:Male; D008390:Markov Chains; D051379:Mice; D009928:Organ Specificity; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013094:Spermatozoa / Q000737:chemistry / Q000378:metabolism; D013438:Sulfhydryl Compounds / Q000378:metabolism; D013737:Testis / Q000737:chemistry / Q000378:metabolism*; D044763:Ubiquitin-Conjugating Enzymes / Q000378:metabolism*
chemical_list: D004952:Esters; D013438:Sulfhydryl Compounds; D044763:Ubiquitin-Conjugating Enzymes