title: Identification and functional characterization of a putative 17β-hydroxysteroid dehydrogenase 12 in abalone (Haliotis diversicolor supertexta).
abstract: The 17β-hydroxysteroid dehydrogenases (17β-HSDs) are key enzymes in the downstream process of steroid hormone biosynthesis. To date, relatively little is known about the role of 17β-HSDs in marine gastropods. In the present study, a putative cDNA sequence encoding type 12 17β-HSD (17β-HSD-12) was identified in abalone (Haliotis diversicolor supertexta). The full-length cDNA was 1,978 bp, including an open reading frame (ORF) of 963 bp that encoded a protein of 321 amino acids. Comparative structural analysis revealed that abalone 17β-HSD-12 shared 39.8-42.8% amino acid identity with other 17β-HSD-12 homologues and that the functional domains were well conserved. Phylogenetic analysis revealed that abalone 17β-HSD-12 belonged to the short-chain dehydrogenases/reductases (SDRs) family. Functional analysis following transient transfection of the ORF in human embryonic kidney-293 (HEK-293) cells indicated that abalone 17β-HSD-12 had the ability to convert estrone (E1) into estradiol (E2). Expression analysis in vivo demonstrated that abalone 17β-HSD-12 was differentially expressed during the three reproductive stages (pre-spawning, spawning, and post-spawning). These results indicate that abalone 17β-HSD-12 is an SDR family member with a key role in steroidogenesis during the reproductive period.
authors.affiliation: Life Sciences Division, Graduate School at Shenzhen, Campus of Tsinghua University, Shenzhen, Room 304, Building L, University Town, Guangdong Province, People's Republic of China.
authors.forename: Jin
authors.initials: J
authors.lastname: Zhou
authors.forename: Yun-Feng
authors.initials: YF
authors.lastname: Gao
authors.forename: Lei
authors.initials: L
authors.lastname: Li
authors.forename: Hong-Ning
authors.initials: HN
authors.lastname: Zhai
authors.forename: Shang-Jin
authors.initials: SJ
authors.lastname: Tan
authors.forename: Zhong-Hua
authors.initials: ZH
authors.lastname: Cai
mesh_terms: D015067:17-Hydroxysteroid Dehydrogenases / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D057075:Enzyme Assays; D041981:Gastrointestinal Tract / Q000378:metabolism; D049851:Gastropoda / Q000201:enzymology*; D006066:Gonads / Q000378:metabolism; D008969:Molecular Sequence Data; D009928:Organ Specificity; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D014158:Transcription, Genetic
chemical_list: D015067:17-Hydroxysteroid Dehydrogenases