Functional characterization of two 20β-hydroxysteroid dehydrogenase type 2 homeologs from Xenopus laevis reveals multispecificity

The African clawed frog, Xenopus laevis, is a versatile model for biomedical research and largely similar to mammals in terms of organ development, anatomy, physiology, hormonal signaling mechanisms. Steroid hormones control variety processes their levels are regulated by hydroxysteroid dehydrogenases (HSDs). subfamily 20β-HSD type 2 enzymes currently comprises eight members from teleost fish mammals. Here, we report the identification three genes X. tropicalis laevis functional characterization two homeologs laevis. Hsd20b2.L Hsd20b2.S showed high sequence identity with known mapped subgenomes allotetraploid frog genome. Both expressed during embryonic development adult tissues, strongest signals liver, kidney, intestine, skin. After recombinant expression human cell lines, both co-localized endoplasmic reticulum catalyzed conversion cortisone 20β-dihydrocortisone. 20β-reduction further C21 steroids (17α-hydroxyprogesterone, progesterone, 11-deoxycortisol, 11-deoxycorticosterone), while only was able convert corticosterone cortisol 20β-reduced metabolites. Estrone poor androstenedione no substrate enzymes. Our results demonstrate multispecificity other probably involved steroid catabolism generation pheromones intraspecies communication. A role oocyte maturation unlikely.