DAX1
Template:PBB DAX1 (dosage-sensitive sex reversal, adrenal hypoplasia critical region, on chromosome X, gene 1) is a nuclear receptor protein that in humans is encoded by the NR0B1 gene (nuclear receptor subfamily 0, group B, member 1).[1][2][3] The NR0B1 gene is located on the short (p) arm of the X chromosome between positions 21.3 and 21.2, from base pair 30,082,120 to base pair 30,087,136.
Function
This gene encodes a protein that lacks the normal DNA-binding domain contained in other nuclear receptors.[4] The encoded protein acts as a dominant-negative regulator of transcription of other nuclear receptors including steroidogenic factor 1.[5] This protein also functions as an anti-testis gene by acting antagonistically to SRY. Mutations in this gene result in both X-linked congenital adrenal hypoplasia and hypogonadotropic hypogonadism.[1]
DAX1 plays an important role in the normal development of several hormone-producing tissues. These tissues include the adrenal glands, the pituitary gland and hypothalamus which are located in the brain and the male and female reproductive structures (the testes and ovaries). DAX1 controls the activity of certain genes in the cells that form these tissues during embryonic development. Proteins that control the activity of other genes are known as transcription factors. DAX1 also plays a role in regulating hormone production in these tissues after they have been formed.
Role in disease
X-linked adrenal hypoplasia congenita is caused by mutations in the NR0B1 gene. More than 90 NR0B1 mutations that cause X-linked adrenal hypoplasia congenita have been identified. Many of these mutations delete all or part of the NR0B1 gene, preventing the production of DAX1 protein. Some mutations cause the production of an abnormally short protein. Other mutations cause a change in one of the building blocks (amino acids) of DAX1. These mutations are thought to result in a misshapen, nonfunctional protein. Loss of DAX1 function leads to adrenal insufficiency and hypogonadotropic hypogonadism, which are the main characteristics of this disorder.
Duplication of genetic material on the X chromosome in the region that contains the NR0B1 gene can cause a condition called dosage-sensitive sex reversal. The extra copy of the NR0B1 gene prevents the formation of male reproductive tissues. People who have this duplication usually appear to be female, but are genetically male with both an X and a Y chromosome.
In some cases, genetic material is deleted from the X chromosome in a region that contains several genes, including NR0B1. This deletion results in a condition called adrenal hypoplasia congenita with complex glycerol kinase deficiency. In addition to the signs and symptoms of adrenal hypoplasia congenita, individuals with this condition may have elevated levels of lipids in their blood and urine and may have problems regulating blood sugar levels. In rare cases, the amount of genetic material deleted is even more extensive and affected individuals also have Duchenne muscular dystrophy.
Interactions
DAX1 has been shown to interact with:
References
- ^ a b "Entrez Gene: NR0B1 nuclear receptor subfamily 0, group B, member 1".
- ^ Walker AP, Chelly J, Love DR, Brush YI, Récan D, Chaussain JL, Oley CA, Connor JM, Yates J, Price DA (1992). "A YAC contig in Xp21 containing the adrenal hypoplasia congenita and glycerol kinase deficiency genes". Hum. Mol. Genet. 1 (8): 579–85. doi:10.1093/hmg/1.8.579. PMID 1301166.
{{cite journal}}: Unknown parameter|month=ignored (help)CS1 maint: multiple names: authors list (link) - ^ Goodfellow PN, Camerino G (1999). "DAX-1, an 'antitestis' gene". Cell. Mol. Life Sci. 55 (6–7): 857–63. doi:10.1007/PL00013201. PMID 10412368.
{{cite journal}}: Unknown parameter|month=ignored (help) - ^ McCabe ER (2007). "DAX1: Increasing complexity in the roles of this novel nuclear receptor". Mol. Cell. Endocrinol. 265–266: 179–82. doi:10.1016/j.mce.2006.12.017. PMC 1847396. PMID 17210221.
{{cite journal}}: Unknown parameter|month=ignored (help) - ^ Iyer AK, McCabe ER (2004). "Molecular mechanisms of DAX1 action". Mol. Genet. Metab. 83 (1–2): 60–73. doi:10.1016/j.ymgme.2004.07.018. PMID 15464421.
- ^ Altincicek B, Tenbaum SP, Dressel U, Thormeyer D, Renkawitz R, Baniahmad A (2000). "Interaction of the corepressor Alien with DAX-1 is abrogated by mutations of DAX-1 involved in adrenal hypoplasia congenita". J. Biol. Chem. 275 (11): 7662–7. doi:10.1074/jbc.275.11.7662. PMID 10713076.
{{cite journal}}: Unknown parameter|month=ignored (help)CS1 maint: multiple names: authors list (link) CS1 maint: unflagged free DOI (link) - ^ a b Sugawara T, Abe S, Sakuragi N, Fujimoto Y, Nomura E, Fujieda K, Saito M, Fujimoto S (2001). "RIP 140 modulates transcription of the steroidogenic acute regulatory protein gene through interactions with both SF-1 and DAX-1". Endocrinology. 142 (8): 3570–7. doi:10.1210/en.142.8.3570. PMID 11459805.
{{cite journal}}: Unknown parameter|month=ignored (help)CS1 maint: multiple names: authors list (link) - ^ a b Lopez D, Shea-Eaton W, Sanchez MD, McLean MP (2001). "DAX-1 represses the high-density lipoprotein receptor through interaction with positive regulators sterol regulatory element-binding protein-1a and steroidogenic factor-1". Endocrinology. 142 (12): 5097–106. doi:10.1210/en.142.12.5097. PMID 11713202.
{{cite journal}}: Unknown parameter|month=ignored (help)CS1 maint: multiple names: authors list (link)
Further reading
External links
- GeneReviews/NCBI/NIH/UW entry on 46,XY Disorder of Sex Development and 46,XY Complete Gonadal Dysgenesis
- OMIM entries on 46,XY Disorder of Sex Development and 46,XY Complete Gonadal Dysgenesis
- GeneReviews/NIH/NCBI/UW entry on X-Linked Adrenal Hypoplasia Congenita including Complex Glycerol Kinase Deficiency
- GeneCard for NR0B1