Adrenal hypoplasia congentia (AHC) is an X-linked disorder characterized by primary adrenal insufficiency. The disorder, which is lethal if untreated, results in adrenal insufficiency early in infancy and is characterized by low serum concentration of glucocorticoids, mineralcorticoids and androgens and failure to respond to ACTH. AHC has been mapped to chromosome Xp21 at the same or close to an X-linked locus involved in sex determination, DSS (for dosage-sensitive sex reversal). The gene corresponding to DSS and AHC (designated DAX-1 for DSS-AHC critical region on the X chromosome, gene 1) has been cloned and shown to be deleted in AHC deletion patients and mutated in AHC non-deletion patients. The carboxy terminal 250 amino acids of the DAX-1-encoded protein, DAX-1, exhibits approximately 50% continuous similarity to the ligand-binding domain of the members of the nuclear hormone receptor superfamily while the amino terminal domain contains a putative DNA-binding motif. DAX-1 binds to retinoic acid responsive elements and down regulates retinoic acid receptor-mediated transcriptional activation.
Function:
Orphan nuclear receptor. Component of a cascade required for the development of the hypothalamic-pituitary-adrenal-gonadal axis. Acts as a coregulatory protein that inhibits the transcriptional activity of other nuclear receptors through heterodimeric interactions. May also have a role in the development of the embryo and in the maintenance of embryonic stem cell pluripotency.
Subunit:
Homodimer. Interacts with NR5A1, NR5A2, NR0B2 and with COPS2.
Subcellular Location:
Nucleus. Cytoplasm. Shuttles between the cytoplasm and nucleus. Homodimers exits in the cytoplasm and in the nucleus.
DISEASE:
Defects in NR0B1 are the cause of X-linked adrenal hypoplasia congenital (XL-AHC) [MIM:300200]; also known as X-linked Addison disease (AHX). XL-AHC is a developmental disorder of the adrenal gland that results in profound hormonal deficiencies and is lethal if untreated. It is characterized by the absence of the permanent zone of the adrenal cortex and by a structural disorganization of the glands. Hypogonadotropic hypogonadism (HHG) is frequently associated with this disorder. HHG is a condition resulting from or characterized by abnormally decreased gonadal function, with retardation of growth and sexual development.
Defects in NR0B1 are the cause of 46,XY sex reversal type 2 (SRXY2) [MIM:300018]. It is a condition characterized by male-to-female sex reversal in the presence of a normal 46,XY karyotype. Note=XY individuals with a duplication of part of the short arm of the X chromosome and an intact SRY gene develop as females. The single X chromosome in these individuals does not undergo X-chromosome inactivation; therefore, these individuals presumably carry 2 active copies of genes, including the NR0B1 gene, in the duplicated region. Individuals with deletion of this region develop as males. Genes within the dosage-sensitive sex reversal region are, therefore, not essential for testis development, but, when present in a double dose, interfere with testis formation.
Similarity:
Belongs to the nuclear hormone receptor family. NR0 subfamily.
SWISS:
P51843
Gene ID:
190
Database links:
Entrez Gene: 450140 Chimpanzee
Entrez Gene: 190 Human
Entrez Gene: 11614 Mouse
Omim: 300473 Human
SwissProt: Q9BG97 Chimpanzee
SwissProt: P51843 Human
SwissProt: Q61066 Mouse
Unigene: 268490 Human
Unigene: 536 Mouse
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