Cloning, characterization and functional expression of Taenia solium 17 beta-hydroxysteroid dehydrogenase.
The 17β-hydroxysteroid dehydrogenases (17β-HSD) are key enzymes involved in the formation (reduction) and inactivation (oxidation) of sex steroids. Several types have been found in vertebrates including fish, as well as in invertebrates like Caenorhabditis elegans, Ciona intestinalis and Haliotis diversicolor supertexta. To date limited information is available about this enzyme in parasites. We showed previously that Taenia solium cysticerci are able to synthesize sex steroid hormones in vitro when precursors are provided in the culture medium. Here, we identified a T. solium 17β-HSD through in silico blast searches in the T. solium genome database. This coding sequence was amplified by RT-PCR and cloned into the pcDNA 3.1(+) expression vector. The full length cDNA contains 957bp, corresponding to an open reading frame coding for 319 aa. The highest identity (84%) at the protein level was found with the Echinococcus multilocularis 17β-HSD although significant similarities were also found with other invertebrate and vertebrate 17β-HSD sequences. The T. solium Tsol-17βHSD belongs to the short-chain dehydrogenase/reductase (SDR) protein superfamily. HEK293T cells transiently transfected with Tsol17β-HSD induced expression of Tsol17β-HSD that transformed 3H-androstenedione into testosterone. In contrast, 3H-estrone was not significantly transformed into estradiol. In conclusion, T. solium cysticerci express a 17β-HSD that catalyzes the androgen reduction. The enzyme belongs to the short chain dehydrogenases/reductase family and shares motifs and activity with the type 3 enzyme of some other species.
Dpto. de Fisiología, Biofísica y Neurociencias, CINVESTAV del I.P.N., Apdo. Postal 14-740, 07000 México, D.F., Mexico.
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Aceves-Ramos
Dpto. de Inmunología, Instituto de Investigaciones Biomédicas, UNAM, México, D.F., Mexico.
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de la Torre
Dpto. de Fisiología, Biofísica y Neurociencias, CINVESTAV del I.P.N., Apdo. Postal 14-740, 07000 México, D.F., Mexico.
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Hinojosa
Dpto. de Fisiología, Biofísica y Neurociencias, CINVESTAV del I.P.N., Apdo. Postal 14-740, 07000 México, D.F., Mexico.
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Ponce
Dpto. de Fisiología, Biofísica y Neurociencias, CINVESTAV del I.P.N., Apdo. Postal 14-740, 07000 México, D.F., Mexico.
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García-Villegas
Dpto. de Inmunología, Instituto de Investigaciones Biomédicas, UNAM, México, D.F., Mexico.
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Laclette
Dpto. de Inmunología, Instituto de Investigaciones Biomédicas, UNAM, México, D.F., Mexico.
R J
RJ
Bobes
Dpto. de Fisiología, Biofísica y Neurociencias, CINVESTAV del I.P.N., Apdo. Postal 14-740, 07000 México, D.F., Mexico. Electronic address: mromano@fisio.cinvestav.mx.
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Romano
D015067:17-Hydroxysteroid Dehydrogenases / Q000235:genetics* / Q000378:metabolism*; D000595:Amino Acid Sequence; D000735:Androstenedione / Q000096:biosynthesis; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D005786:Gene Expression Regulation; D012739:Gonadal Steroid Hormones / Q000096:biosynthesis*; D057809:HEK293 Cells; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny; D041201:Taenia solium / Q000201:enzymology* / Q000235:genetics*; D013739:Testosterone / Q000096:biosynthesis
D012739:Gonadal Steroid Hormones; D013739:Testosterone; D000735:Androstenedione; D015067:17-Hydroxysteroid Dehydrogenases; C044256:3 (or 17)-beta-hydroxysteroid dehydrogenase
17β-HSD; Cloning; Parasites; Steroid synthesis; Taenia solium cysticerci; Transfection