NCBI Summary:
The 17-beta-hydroxysteroid dehydrogenase enzyme (EC 1.1.1.62) oxidizes or reduces estrogens and androgens in mammals and regulates the biologic potency of these steroids.[supplied by OMIM]
General function
Enzyme, Oxidoreductase
Comment
Cellular localization
Comment
Ovarian function
Luteinization
Comment
Hsd17b7 (PRAP/17{beta}-Hydroxysteroid Dehydrogenase Type 7) Gene Plays a Crucial Role in Embryonic Development and Fetal Survival. Shehu A et al. Our laboratory has previously cloned and purified a protein named PRAP that was shown to be a novel 17beta-HSD enzyme with dual activity. This enzyme, renamed HSD17B7 or PRAP/17beta-HSD7, converts estrone to estradiol and is also involved in cholesterol biosynthesis. The major site of its expression is the corpus luteum of a great number of species including rodents and humans. To examine the functional significance of HSD17B7 in pregnancy, we generated a knockout mouse model with targeted deletions of exons 1 through 4 of this gene. We anticipated a mouse with a severe fertility defect due to its inability to regulate estrogen levels during pregnancy. The heterozygous mutant mice are normal in their development and gross anatomy. The females cycle normally and both male and female are fertile with normal litter size. To our surprise, the breeding of heterozygous mice yielded no viable HSD17B7 null mice. However, we found HSD17B7 null embryo alive in utero on day 8.5 and 9.5. By day 10.5, the fetuses to grow and suffer from severe brain malformation and heart defect. Because the brain depends on in situ cholesterol biosynthesis for its development beginning at day 10, the major cause of fetal death appears to be due to the cholesterol synthetic activity of this enzyme. By ablating HSD17B7 function, we have uncovered, in vivo, an important requirement for this enzyme during fetal development.
Expression regulated by
LH
Comment
Ovarian localization
Granulosa
Comment
Changes in mouse granulosa cell gene expression during early luteinization. McRae RS et al. Changes in gene expression during granulosa cell luteinization have been measured using serial analysis of gene expression (SAGE). Immature normal mice were treated with pregnant mare serum gonadotropin (PMSG) or PMSG followed, 48 h later, by human chorionic gonadotropin (hCG). Granulosa cells were collected from preovulatory follicles after PMSG injection or PMSG/hCG injection and SAGE libraries generated from the isolated mRNA. The combined libraries contained 105,224 tags representing 40,248 unique transcripts. Overall, 715 transcripts showed a significant difference in abundance between the two libraries of which 216 were significantly down-regulated by hCG and 499 were significantly up-regulated. Among transcripts differentially regulated, there were clear and expected changes in genes involved in steroidogenesis as well as clusters of genes involved in modeling of the extracellular matrix, regulation of the cytoskeleton and intra and intercellular signaling. The SAGE libraries described here provide a base for functional investigation of the regulation of granulosa cell luteinization.