AR
AR (androgen receptor, also known as NR3C4, DHTR and HUMARA) is a steroid-hormone-activated transcription factor of the nuclear hormone receptor family. After binding its ligand it moves into the nucleus and stimulates transcription of androgen-responsive genes. Browse Assay Genie's current range of AR research reagents below, or read on for the biology behind the target.
AR functions as a steroid-hormone-activated transcription factor. In its unliganded state it is associated with accessory proteins. Upon binding the hormone ligand, the receptor dissociates from these accessory proteins, translocates into the nucleus, dimerises and then stimulates transcription of androgen-responsive genes. UniProt lists the protein in both the cytoplasm and the nucleus, which reflects this ligand-dependent movement.
The AR gene is more than 90 kb long and encodes a protein with three major functional domains: the N-terminal domain, the DNA-binding domain and the androgen-binding domain. The protein belongs to the nuclear hormone receptor family and the NR3 subfamily, and HGNC places it in nuclear receptor subfamily 3 group C. The N-terminal transactivation domain is encoded by a region containing two polymorphic trinucleotide repeat segments, which encode polyglutamine and polyglycine tracts. Alternative splicing produces multiple transcript variants and different isoforms. UniProt notes that an isoform lacking the C-terminal ligand-binding domain may constitutively activate transcription of a specific set of genes independently of steroid hormones. Mouse and rat both carry an orthologous Ar gene.
The gene has been known under several names, including dihydrotestosterone receptor, AIS, NR3C4, SMAX1, HUMARA and DHTR. Two of these historical names point to disease. Expansion of the polyglutamine tract from the normal 9-34 repeats to the pathogenic 38-62 repeats causes spinal and bulbar muscular atrophy (SBMA, also called Kennedy's disease). Mutations in the gene are also associated with complete androgen insensitivity (CAIS). These links make the androgen receptor protein a frequent subject in studies of hormone signalling and of repeat-expansion disorders.
AR mediates the transcriptional response to androgens, so it is central to studies of how hormone binding leads to nuclear translocation and activation of responsive genes.
As a member of the NR3 subfamily, AR is used to examine ligand-dependent receptor activation, dimerisation and the release of accessory proteins.
Expansion of the polyglutamine tract in AR causes spinal and bulbar muscular atrophy, making the receptor a focus for work on this neuromuscular disorder.
Mutations in the AR gene are associated with complete androgen insensitivity, so the receptor is studied to understand how altered function disrupts androgen response.
AR is a steroid-hormone-activated transcription factor. When it binds its hormone ligand, it dissociates from accessory proteins, translocates into the nucleus, dimerises and stimulates transcription of androgen-responsive genes. Its three major domains are the N-terminal domain, the DNA-binding domain and the androgen-binding domain.
AR is also called androgen receptor, dihydrotestosterone receptor, NR3C4, DHTR, HUMARA, SMAX1 and AIS. Alternative splicing gives multiple transcript variants and isoforms. UniProt notes one form lacking the ligand-binding domain that may activate certain genes independently of steroid hormones.
Expansion of the polyglutamine tract in AR, from the normal 9-34 repeats to 38-62 repeats, causes spinal and bulbar muscular atrophy (Kennedy's disease). Mutations in the gene are also associated with complete androgen insensitivity. Mouse and rat have orthologous Ar genes; check the datasheet of any product for its validated reactivity.
Other steroid hormone receptors and androgen-signalling markers with products at Assay Genie.
Gene and protein annotations from HGNC, NCBI Gene and UniProt P10275; product specifications from Assay Genie datasheets.