| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
Baker Heart Research Institute (Z.C., P.B., V.O., G.E., C.E., Z.K.), Melbourne, Victoria 8008, Australia; First Department of Surgery and Pathology, Tohoku University, School of Medicine, Sendai, Miyagi 980-8575, Japan (T.S., H.S.); and Murdoch Childrens Research Institute (R.S.), Melbourne 3052, Australia; and Prince Henrys Institute (P.F.), Melbourne 3168, Australia
Address all correspondence and requests for reprints to: Zygmunt Krozowski, Ph.D., Baker Heart Research Institute, P.O. Box 6492, St. Kilda Road, Central Melbourne, Victoria 8008, Australia. E-mail: zygmunt.krozowski{at}baker.edu.au.
We searched expressed sequence tag databases with conserved domains of the short-chain alcohol dehydrogenase superfamily and identified another isoform of 17ß-hydroxysteroid dehydrogenase, 17ßHSDXI. This enzyme converts 5
-androstane-3
, 17ß-diol to androsterone. The substrate has been implicated in supporting gestation and modulating
-aminobutyric acid receptor activity. 17ßHSDXI is colinear with human retinal short-chain dehydrogenase/reductase retSDR2, a protein with no known biological activity (accession no. AAF06939). Of the proteins with known function, 17ßHSDXI is most closely related to the retinol-metabolizing enzyme retSDR1, with which it has 30% identity. There is a polymorphic stretch of 15 adenosines in the 5' untranslated region of the cDNA sequence and a silent polymorphism at C719T. A 17ßHSDXI construct with a stretch of 20 adenosines was found to produce significantly more enzyme activity than constructs containing 15 or less adenosines (43% vs. 26%, P < 0.005). The C719T polymorphism is present in 15% of genomic DNA samples. Northern blot analysis showed high levels of 17ßHSDXI expression in the pancreas, kidney, liver, lung, adrenal, ovary, and heart. Immunohistochemical staining for 17ßHSDXI is strong in steroidogenic cells such as syncytiotrophoblasts, sebaceous gland, Leydig cells, and granulosa cells of the dominant follicle and corpus luteum. In the adrenal 17ßHSDXI, staining colocalized with the distribution of 17
-hydroxylase but was stronger in the mid to outer cortex. 17ßHSDXI was also found in the fetus and increased after birth. Liver parenchymal cells and epithelium of the endometrium and small intestine also stained. Regulation studies in mouse Y1 cells showed that cAMP down-regulates 17ßHSDXI enzymatic activity (40% vs. 32%, P < 0.05) and reduces gene expression to undetectable levels. All-trans-retinoic acid did not affect 17ßHSDXI expression or activity, but addition of the retinoid together with cAMP significantly decreased activity over cAMP alone (32% vs. 23%, P < 0.05). Cloning and sequencing of the 17ßHSDXI promoter identified the potential nuclear receptor steroidogenic factor-1 half-site TCCAAGGCCGG, and a cluster of three other potential steroidogenic factor-1 half-sites were found in the distal part of intron 1. Collectively, these results suggest a role for 17ßHSDXI in androgen metabolism during steroidogenesis and a possible role in nonsteroidogenic tissues including paracrine modulation of 5
-androstane-3
, 17ß-diol levels. 17ßHSDXI could act by metabolizing compounds that stimulate steroid synthesis and/or by generating metabolites that inhibit it.
This article has been cited by other articles:
![]() |
J. M Day, H. J Tutill, A. Purohit, and M. J Reed Design and validation of specific inhibitors of 17{beta}-hydroxysteroid dehydrogenases for therapeutic application in breast and prostate cancer, and in endometriosis Endocr. Relat. Cancer, September 1, 2008; 15(3): 665 - 692. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. Ashibe, T. Hirai, K. Higashi, K. Sekimizu, and K. Motojima Dual Subcellular Localization in the Endoplasmic Reticulum and Peroxisomes and a Vital Role in Protecting against Oxidative Stress of Fatty Aldehyde Dehydrogenase Are Achieved by Alternative Splicing J. Biol. Chem., July 13, 2007; 282(28): 20763 - 20773. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Endocrinology | Endocrine Reviews | J. Clin. End. & Metab. |
| Molecular Endocrinology | Recent Prog. Horm. Res. | All Endocrine Journals |