Protein / target
3-oxo-5-alpha-steroid 4-dehydrogenase 2
Protein at a glance
Biological role
3-oxo-5-alpha-steroid 4-dehydrogenase (NADP+)
Strongest disease association
46,XY disorder of sex development due to 5-alpha-reductase 2 deficiency
Therapeutic position
Established drug target
Derived from structured UniProt, Open Targets and literature data on this page.
Protein profile
Canonical identity and biological annotation from UniProt.
Function overview
Catalyzes the irreversible stereospecific reduction of the delta 4,5 bond (double bond between carbons 4 and 5) of various 3-oxo steroids (3-keto steroids) producing their 5alpha dihydro-3-oxo forms.
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Catalyzes the irreversible stereospecific reduction of the delta 4,5 bond (double bond between carbons 4 and 5) of various 3-oxo steroids (3-keto steroids) producing their 5alpha dihydro-3-oxo forms (PubMed:10898110, PubMed:23685396). Converts testosterone into 5-alpha-dihydrotestosterone (DHT), the most active androgen in the prostate, as it is the preferred ligand for androgen receptor (AR) transactivation, making this reaction a key step in male sexual differentiation during development (PubMed:10898110, PubMed:23685396). Besides testosterone, it can also act on other steroids, including progesterone, producing metabolites with diverse roles (PubMed:10898110). Hence, it plays a central role in sexual differentiation and androgen physiology (PubMed:10898110)
Subcellular location
Domains and Gene Ontology detail (28)Hide
Gene Ontology
- Ccell body fiber
- Cendoplasmic reticulum membrane
- Cneuronal cell body
- F3-oxo-5-alpha-steroid 4-dehydrogenase (NADP+) activity
- F3-oxo-5-alpha-steroid 4-dehydrogenase activity
- Famide binding
- Ftestosterone dehydrogenase (NADP+) activity
- Pandrogen biosynthetic process
- Pandrogen metabolic process
- Pbone development
- Pcell differentiation
- Pcell-cell signaling
Biological roles
What this protein does, drawn together from its UniProt function, Gene Ontology terms and Reactome pathways.
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Metabolic enzyme activity
- ·3-oxo-5-alpha-steroid 4-dehydrogenase (NADP+) activity
- ·3-oxo-5-alpha-steroid 4-dehydrogenase activity
- ·testosterone dehydrogenase (NADP+) activity
- ·androgen metabolic process
View underlying pathways (1)Hide underlying pathways
Concepts derived from UniProt GO Reactome — each badge above shows which sources supported that role.
Interaction neighbourhood
Proteins with the strongest functional or physical association. Node size and line weight reflect STRING confidence; hover or select a partner to inspect one association.
Functional and physical associations from STRING v12.0. Only associations with this protein are drawn — partner-to-partner links are not part of this evidence.
Approved medicines with mapped indications
Approved therapies targeting this protein, grouped by what they are approved to treat — the disease-first view of the medicines below. Relationships come from the canonical approved-indication graph (ChEMBL phase-4), the same source as the drug cards.
3 medicines meet Open Targets' target-level approved-medicine definition; the 2 shown here are those on this page with a canonical approved disease indication in the graph. Approved indications from ChEMBL (phase-4), via the canonical drug→disease graph.
Drugs targeting this protein
How approved and investigational drugs engage this protein — mechanism and action type, direct vs complex targeting, and how broadly each acts across other targets. A drug-first view (the section above groups the approved ones disease-first); direct binders with few recorded targets are listed first.
Steroid 5-alpha-reductase 2 inhibitor
Indicated for Alopecia, Prostatic Neoplasms
ChEMBL mechanism, action type, target identity and approved indications. Open Targets clinical status.
Translational evidence
Why this target matters therapeutically, strongest evidence first. Disease associations are gene-level (via the gene that encodes this protein) and open into the full confidence synthesis; the development universe, tractability and safety annotations are target-level, from Open Targets.
Strongest disease associations · via encoding gene SRD5A2
Gene-level evidence surfaced through the gene SRD5A2that encodes this protein — not a direct protein–disease relationship. Ranked by Forefront's causal-directness weighting, so genetically- and clinically-evidenced diseases lead over ones that merely share the literature.
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The evidence agreement range shows how closely the independent evidence families agree — it is not a statistical confidence interval, and nothing here is fitted to outcome data. Derived from Open Targets evidence types under Forefront weighting; the per-type scores above show the calculation.
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Drug development
3 compounds recorded · 3 approved
View all recorded compounds (3)Hide
Open Targets known-drugs universe. Drug name and highest clinical stage only — the disease relationship is NOT read from this slice (it carries trial-context noise); approved indications come from the canonical graph above.
Tractability
Small molecules — Strong
Antibodies — Emerging
Protein degraders — Emerging
View underlying tractability evidence (6)Hide
Raw Open Targets tractability assessment buckets, by modality.
Clinical trials
Trials of drugs that target this protein — reached indirectly through those drugs, so a trial listed here studies the drug, not the protein. Ranked by active status, then clinical phase and recency, and spread across the targeting drugs.
View all trials (26)Hide
ClinicalTrials.gov via the drug-target graph.
What's happening now
Recent therapeutic activity around this target — regulatory actions, clinical trials and safety signals for 2 drugs that target this protein, plus publications where such a drug is a genuine subject. Every item is reached indirectly through the drug, not the protein itself; incidental mentions (a paper that merely measures a drug) and press items are excluded.
- Label change
Label change: FINASTERIDE (ANDA076511)
- Label change
Label change: FINASTERIDE (ANDA090121)
- Label change
Label change: FINASTERIDE (ANDA076437)
- Label change
Label change: FINASTERIDE (ANDA078341)
- Label change
Label change: FINASTERIDE (ANDA076511)
- New publicationAR alterations inform circulating tumor DNA detection in metastatic castration resistant prostate cancer patients.
- New publicationLuteinizing hormone-releasing hormone receptor agonists and antagonists in prostate cancer: effects on long-term survival and combined therapy with next-generation hormonal agents.
- New publicationCirculating Tumor DNA Assessment for Treatment Monitoring Adds Value to PSA in Metastatic Castration-Resistant Prostate Cancer.
- Safety communication
Drug Safety Update: Finasteride: reminder of the risk psychiatric side effects and of sexual side effects (which may persist after discontinuation of treatment)
- New publicationRucaparib or Physician's Choice in Metastatic Prostate Cancer.
- Safety communication
Drug Safety Update: Finasteride: rare reports of depression and suicidal thoughts
- Safety communication
Drug Safety Update: Finasteride: potential risk of male breast cancer
Objective event titles are shown unmodified; the event kind and significance line are derived from structured fields. Forefront AttentionEvent stream aggregating Europe PMC Regulatory filings ClinicalTrials.gov.