The human
gene
In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ...
''SRD5A2'' encodes the 3-oxo-5α-steroid 4-dehydrogenase 2 enzyme, also known as 5α-reductase type 2 (5αR2),
one of three isozymes of
5α-reductase.
5αR2 catalyzes the conversion of the male sex hormone
testosterone
Testosterone is the primary sex hormone and anabolic steroid in males. In humans, testosterone plays a key role in the development of male reproductive tissues such as testes and prostate, as well as promoting secondary sexual characteristi ...
into the more potent
androgen
An androgen (from Greek ''andr-'', the stem of the word meaning "man") is any natural or synthetic steroid hormone that regulates the development and maintenance of male characteristics in vertebrates by binding to androgen receptors. This in ...
,
dihydrotestosterone
Dihydrotestosterone (DHT, 5α-dihydrotestosterone, 5α-DHT, androstanolone or stanolone) is an endogenous androgen sex steroid and hormone. The enzyme 5α-reductase catalyzes the formation of DHT from testosterone in certain tissues includ ...
.
5αR2 is a
microsomal protein expressed at high levels in androgen-sensitive tissues such as the
prostate
The prostate is both an accessory gland of the male reproductive system and a muscle-driven mechanical switch between urination and ejaculation. It is found only in some mammals. It differs between species anatomically, chemically, and phys ...
. The enzyme is active at acidic pH and is sensitive to the 4-azasteroid inhibitor
finasteride. Deficiencies in 5αR2 activity of the can lead to a condition known as
5α-reductase 2 deficiency, which is a cause of 46,XY DSD that presents as atypical male genitalia.
See also
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5α-Reductase
References
Further reading
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