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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-3
pubmed:dateCreated
1992-1-2
pubmed:abstractText
The isolation, cloning and expression of a DNA insert complementary to mRNA encoding rat testis 3 beta-hydroxysteroid dehydrogenase/delta 5----4-isomerase (3 beta-HSD) is reported. The insert contains an open reading frame encoding a protein of 373 amino acids, which exhibits 73% and 78% identity to the cDNA encoding the human placental form at the amino acid and nucleotide levels respectively. Northern blot analysis of total RNA of rat tissues using as probe a specific radiolabeled cDNA insert encoding rat testis 3 beta-HSD demonstrated high levels of 1.6 kb mRNA species in ovary, adrenal and Leydig tumor, with lower but detectable message in testis and adult male liver, while the probe also hybridized to a 2.1 kb mRNA species in liver. The cDNA was inserted into a modified pCMV vector and expressed in COS-1 monkey kidney tumor cells. The expressed protein was similar in size to 3 beta-HSD present in H540 Leydig tumor cell homogenate and human placental microsomal 3 beta-HSD, as detected by immunoblot analysis, and catalyzed the conversion of pregnenolone to progesterone, 17 alpha-hydroxypregnenolone to 17 alpha-hydroxyprogesterone, and dehydroepiandrosterone to androstenedione. Transfected COS cell homogenates, supplemented with NAD+, but not NADP+, converted pregnenolone to progesterone and dehydroepiandrosterone to androstenedione with apparent Km values of 0.13 and 0.09 microM, respectively. Immunoblot analysis of various rat tissues using a polyclonal antibody directed against human placental 3 beta-HSD, in addition to immunoreactivity in the adrenal and testis, demonstrated immunoreactive 3 beta-HSD protein in adult male liver, but not in adult female or fetal liver. We conclude that while one gene product is highly expressed in testicular Leydig cells, and probably adrenal and ovary, accounting for their 3 beta-HSD content, a 3 beta-HSD is also expressed in liver in a sex-specific manner.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0303-7207
pubmed:author
pubmed:issnType
Print
pubmed:volume
80
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
21-31
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:1955079-Amino Acid Sequence, pubmed-meshheading:1955079-Animals, pubmed-meshheading:1955079-Base Sequence, pubmed-meshheading:1955079-Blotting, Northern, pubmed-meshheading:1955079-Blotting, Western, pubmed-meshheading:1955079-Cell Line, pubmed-meshheading:1955079-Cloning, Molecular, pubmed-meshheading:1955079-DNA, pubmed-meshheading:1955079-Gene Expression, pubmed-meshheading:1955079-Humans, pubmed-meshheading:1955079-Male, pubmed-meshheading:1955079-Molecular Sequence Data, pubmed-meshheading:1955079-Multienzyme Complexes, pubmed-meshheading:1955079-Progesterone Reductase, pubmed-meshheading:1955079-Rats, pubmed-meshheading:1955079-Rats, Inbred F344, pubmed-meshheading:1955079-Sequence Alignment, pubmed-meshheading:1955079-Steroid Isomerases, pubmed-meshheading:1955079-Testis
pubmed:year
1991
pubmed:articleTitle
3 beta-hydroxysteroid dehydrogenase/delta 5----4-isomerase expression in rat and characterization of the testis isoform.
pubmed:affiliation
Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas 75235-9051.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.