Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2001-2-22
pubmed:abstractText
3 alpha-Hydroxysteroid dehydrogenases (3 alpha-HSDs) catalyze the conversion of 3-ketosteroids to 3 alpha-hydroxy compounds. The best known 3 alpha-HSD activity is the transformation of the most potent natural androgen, dihydrotestosterone, into 5 alpha-androstan-3 alpha,17 beta-diol (3 alpha-diol), a compound having much lower activity. Previous reports show that 3 alpha-HSDs are involved in the metabolism of glucocorticoids, progestins, prostaglandins, bile acid precursors, and xenobiotics. 3 alpha-HSDs could, thus, play a crucial role in the control of a series of active steroid levels in target tissues. In the human, type 1 3 alpha-HSD was first identified as human chlordecone reductase. Recently, we have isolated and characterized type 3 3 alpha-HSD that shares 81.7% identity with human type 1 3 alpha-HSD. The transfection of vectors expressing types 1 and 3 3 alpha-HSD in transformed human embryonic kidney (HEK-293) cells indicates that both enzymes efficiently catalyze the transformation of dihydrotestosterone into 3 alpha-diol in intact cells. However, when the cells are broken, the activity of type 3 3 alpha-HSD is rapidly lost, whereas the type 1 3 alpha-HSD activity remains stable. We have previously found that human type 5 17 beta-HSD which possesses 84% and 86% identity with types 1 and 3 3 alpha-HSD, respectively, is also labile, whereas rodent enzymes such as mouse type 5 17 beta-HSD and rat 3 alpha-HSD are stable after homogenization of the cells. The variable stability of different enzymatic activities in broken cell preparations renders the comparison of different enzymes difficult. RNA expression analysis indicates that human type 1 3 alpha-HSD is expressed exclusively in the liver, whereas type 3 is more widely expressed and is found in the liver, adrenal, testis, brain, prostate, and HaCaT keratinocytes. Based on enzymatic characteristics and sequence homology, it is suggested that type 1 3 alpha-HSD is an ortholog of rat 3 alpha-HSD while type 3 3 alpha-HSD, which must have diverged recently, seems unique to human and is probably more involved in intracrine activity.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0021-972X
pubmed:author
pubmed:issnType
Print
pubmed:volume
86
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
841-6
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:11158055-3-Hydroxysteroid Dehydrogenases, pubmed-meshheading:11158055-Adrenal Glands, pubmed-meshheading:11158055-Amino Acid Sequence, pubmed-meshheading:11158055-Animals, pubmed-meshheading:11158055-Brain, pubmed-meshheading:11158055-Cattle, pubmed-meshheading:11158055-Cell Line, pubmed-meshheading:11158055-Humans, pubmed-meshheading:11158055-Hydroxysteroid Dehydrogenases, pubmed-meshheading:11158055-Liver, pubmed-meshheading:11158055-Male, pubmed-meshheading:11158055-Mice, pubmed-meshheading:11158055-Molecular Sequence Data, pubmed-meshheading:11158055-Organ Specificity, pubmed-meshheading:11158055-Phylogeny, pubmed-meshheading:11158055-Prostate, pubmed-meshheading:11158055-RNA, Messenger, pubmed-meshheading:11158055-Rabbits, pubmed-meshheading:11158055-Rats, pubmed-meshheading:11158055-Recombinant Proteins, pubmed-meshheading:11158055-Sequence Alignment, pubmed-meshheading:11158055-Sequence Homology, Amino Acid, pubmed-meshheading:11158055-Substrate Specificity, pubmed-meshheading:11158055-Testis, pubmed-meshheading:11158055-Transfection
pubmed:year
2001
pubmed:articleTitle
Human types 1 and 3 3 alpha-hydroxysteroid dehydrogenases: differential lability and tissue distribution.
pubmed:affiliation
Oncology and Molecular Endocrinology Research Center, Laval University Medical Center (CHUL) and Laval University, Québec G1V 4G2, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't