title: Identification and characterization of canine growth differentiation factor-9 and its splicing variant.
abstract: Growth differentiation factor-9 (GDF-9), a member of the transforming growth factor-β (TGF-β) superfamily, is expressed exclusively in the oocyte within the ovary and plays essential roles in the ovarian function in mammals. However, a possible involvement of GDF-9 in canine ovarian physiology that has a unique ovulation process among mammals has not been studied. Interestingly, we have isolated two types of cDNA clones generated by an alternative splicing from a canine ovarian total RNA. The predominant long form cDNA shares a common precursor structure with GDF-9s in other species whereas the minor short form cDNA has a 172 amino acid truncation in the proregion. Using a transient expression system, we found that the long form cDNA has a defect in mature protein production whereas the short form cDNA readily produces mature protein. However, mutations at one or two N-glycosylation sites in the mature domain of the short form GDF-9 caused a loss in mature protein production. These results suggest that the prodomain and N-linked glycosylation of the mature domain regulate proper processing and secretion of canine GDF-9. Based on the biological functions of GDF-9, these characteristics of canine GDF-9 could be causatively linked to the unique ovulation process in the Canidae.
authors.affiliation: Laboratory of Experimental Animal Science, Kitasato University, School of Veterinary Medicine, Towada, Aomori 034-8628, Japan. ohashim@vmas.kitasato-u.ac.jp
authors.forename: Osamu
authors.initials: O
authors.lastname: Hashimoto
authors.forename: Ryohei
authors.initials: R
authors.lastname: Takagi
authors.forename: Fuminari
authors.initials: F
authors.lastname: Yanuma
authors.forename: Satoru
authors.initials: S
authors.lastname: Doi
authors.forename: Junji
authors.initials: J
authors.lastname: Shindo
authors.forename: Hideki
authors.initials: H
authors.lastname: Endo
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Hasegawa
authors.forename: Shunichi
authors.initials: S
authors.lastname: Shimasaki
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D004285:Dogs / Q000378:metabolism*; D005260:Female; D006031:Glycosylation; D055429:Growth Differentiation Factor 9 / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D008969:Molecular Sequence Data; D010053:Ovary / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D012326:RNA Splicing; D011994:Recombinant Proteins / Q000235:genetics; D016415:Sequence Alignment
chemical_list: D055429:Growth Differentiation Factor 9; D011994:Recombinant Proteins