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.

Sex steroids and steroidogenesis-related genes in the sea cucumber, Holothuria scabra and their potential role in gonad maturation

“…We also identified Hsc3β-HSD and Hsc17β-HSD within the H. scabra transcriptome, of which the 3β-HSD and 17β-HSD are known to be involved in steroidogenesis. To date, many isoforms of the 3β-HSD and 17β-HSD have been broadly reported in invertebrates, including echinoderms 10,23,[61][62][63][64][65][66][67] , which may be involved in the formation of progestogen, estrogens, and androgens. However, sex steroids in invertebrates might be derived from exogenous sources due to a lack of key enzymes involved in steroid biosynthesis 46,47 .…”

Influences of DMP on the Fertilization Process and Subsequent Embryogenesis of Abalone (Haliotis diversicolor supertexta) by Gametes Exposure

“…We cannot totally rule out a role of 17β-HSD in regulating steroid biosynthesis during abalone embryo development. In virtually, the biological function of 17β-HSD-11 [submitted manuscript] and 17β-HSD-12 [50] were verified by transiently transfecting their ORF in HEK-293 cells, which provided further support that abalone 17β-HSD may participate steroid hormone metabolism. Besides, the physiological function of 17β-HSD involved in steroidogenesis or the cascade process has also been demonstrated in sea urchin [51], mussel [52], and dogwhelk [53].…”

Identification and expression analysis of the MSP130-related-2 gene from Hyriopsis cumingii

“…This sequence homology is relatively low, which suggests that MSP130-related-2 has not been highly conserved during evolution. Thus, focusing on its potential functional domains, evolutionary relationships, and biological roles is important (Zhou et al, 2011). Similar to SpMSP130-related-2, HcMSP130-related-2 is predicted to contain a signal sequence and several potential N-glycosylation sites (Figure 1), but it lacks the extended glycine-rich domain found in MSP130 and the C-terminal GPI anchor found in the S. purpuratus MSP130-related-2, which is a valuable model system for analyzing the cellular and molecular regulation of bio-mineralization (Decker and Lennarz, 1988;Benson and Wilt, 1992;Ettensohn et al, 1997;Wilt, 1999).…”