Retinal homeobox protein Rx

Last updated
RAX
Identifiers
Aliases RAX , MCOP3, RX, retina and anterior neural fold homeobox
External IDs OMIM: 601881 MGI: 109632 HomoloGene: 8383 GeneCards: RAX
Orthologs
SpeciesHumanMouse
Entrez
Ensembl
UniProt
RefSeq (mRNA)

NM_013435

NM_013833

RefSeq (protein)

NP_038463

NP_038861

Location (UCSC) Chr 18: 59.27 – 59.27 Mb Chr 18: 66.06 – 66.07 Mb
PubMed search [3] [4]
Wikidata
View/Edit Human View/Edit Mouse

Retinal homeobox protein Rx also known as retina and anterior neural fold homeobox is a protein that in humans is encoded by the RAX gene. [5] The RAX gene is located on chromosome 18 in humans, mice, and rats. [6]

Contents

Function

This gene encodes a homeobox-containing transcription factor that functions in eye development. The gene is expressed early in the eye primordia, and is required for retinal cell fate determination and also regulates stem cell proliferation. [5]

Towards the end of late gastrulation a single eye field has formed and splits into bilateral fields via action by the signaling molecule, sonic hedgehog (Shh) secreted from the forebrain. Rax and Six-3 (also a transcription factor) maintain the forebrain's ability to secrete Shh by inhibiting activity of the signaling molecule Wnt. [7]

Rax (Retina and Anterior Neural Fold Homeobox) is a gene in the OAR (Otx, Arx,& Rax) subgroup of the paired-like homeodomain family of transcription factors. Discovered in 1997, [8] the Rax gene is known to contribute to the development of the retina, hypothalamus, pineal gland and pituitary gland. [9]

Clinical significance

Mutations in this gene have been reported in patients with defects in ocular development, including microphthalmia, anophthalmia, and coloboma. [5]

Mutations to the Rax gene cause malformation of the retinal field, including anophthalmia and microphthalmia. [10]

Individuals who have a mutation in the RAX gene fail to develop ocular structures, referred to as anophthalmia. [7] RAX mutant individuals can also have microphthalmia, where one or both of the eyes is smaller than normal. [6]

Animal studies

Rax genes are conserved among vertebrates. RAX knockout mice have no eyes and abnormal forebrain formation. In the frog Xenopus tropicalis , Rax mutants are eyeless; the future retinal tissue instead has diencephalon and telencephalon features. [11] Due to a genome duplication at the basis of the teleost fish lineage, fishes contain three Rax genes: Rx1, Rx2, and Rx3. [12] Zebrafish and medaka mutants in Rx3 are eyeless. [12] [13]

Related Research Articles

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<span class="mw-page-title-main">SIX3</span> Protein-coding gene in the species Homo sapiens

Homeobox protein SIX3 is a protein that in humans is encoded by the SIX3 gene.

<span class="mw-page-title-main">VSX1</span> Protein-coding gene in the species Homo sapiens

Visual system homeobox 1 is a protein that in humans is encoded by the VSX1 gene.

<span class="mw-page-title-main">VSX2</span> Protein-coding gene in the species Homo sapiens

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<span class="mw-page-title-main">NKX2-2</span> Protein-coding gene in the species Homo sapiens

Homeobox protein Nkx-2.2 is a protein that in humans is encoded by the NKX2-2 gene.

<span class="mw-page-title-main">Homeobox protein goosecoid</span> Protein-coding gene in the species Homo sapiens

Homeobox protein goosecoid(GSC) is a homeobox protein that is encoded in humans by the GSC gene. Like other homeobox proteins, goosecoid functions as a transcription factor involved in morphogenesis. In Xenopus, GSC is thought to play a crucial role in the phenomenon of the Spemann-Mangold organizer. Through lineage tracing and timelapse microscopy, the effects of GSC on neighboring cell fates could be observed. In an experiment that injected cells with GSC and observed the effects of uninjected cells, GSC recruited neighboring uninjected cells in the dorsal blastopore lip of the Xenopus gastrula to form a twinned dorsal axis, suggesting that the goosecoid protein plays a role in the regulation and migration of cells during gastrulation.

<span class="mw-page-title-main">CDON</span> Protein-coding gene in the species Homo sapiens

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<span class="mw-page-title-main">VAX1</span> Protein-coding gene in the species Homo sapiens

Ventral anterior homeobox 1 is a protein that in humans is encoded by the VAX1 gene.

<span class="mw-page-title-main">DBX2</span> Protein-coding gene in humans

Homeobox protein DBX2, also known as developing brain homeobox protein 2, is a protein that in humans is encoded by the DBX2 gene. DBX2 plays an important role in the development of the central nervous system, specifically in the development of the neural tube and brain. DBX2 is located on chromosome 12 and is approximately 36,000 base pairs long. DBX2 is predicted to enable DNA-binding transcription activity as well as being involved in the regulation of transcription by RNA polymerase II.

<span class="mw-page-title-main">TENM3</span> Protein-coding gene in the species Homo sapiens

Teneurin-3, also known as Ten-m3, Odz3, Ten-m/Odz3, Tenascin-like molecule major 3 or Teneurin transmembrane protein 3, is a protein that, in humans, is encoded by the TENM3, or ODZ3, gene. Ten-m3 is a ~300 kDa type II transmembrane glycoprotein that is a member of the teneurin/Ten-m/Odz family. The teneurin family currently consists of four members: Ten-m1-Ten-m4. Ten-ms are conserved across both vertebrate and invertebrate species. They are expressed in distinct, but often interconnected, areas of the developing nervous system and in some non-neural tissues. Like the Ten-m family, Ten-m3 plays a critical role in regulating connectivity of the nervous system, particularly in axon pathfinding and synaptic organisation in the motor and visual system. Mutation in the TENM3/ODZ3 gene in humans has been associated with the eye condition, microphthalmia.

<span class="mw-page-title-main">CDX4 (gene)</span> Protein-coding gene in humans

Homeobox protein CDX-4 is a protein that in humans is encoded by the CDX4 gene. This gene is a member of the caudal-related homeobox transcription factor family that also includes CDX1 and CDX2.

Makoto Furutani-Seiki is a Japanese molecular biologist who is a Professor of Systems Biochemistry in the School of Medicine at Yamaguchi University, Japan.

References

  1. 1 2 3 GRCh38: Ensembl release 89: ENSG00000134438 - Ensembl, May 2017
  2. 1 2 3 GRCm38: Ensembl release 89: ENSMUSG00000024518 - Ensembl, May 2017
  3. "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  4. "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  5. 1 2 3 "Entrez Gene: Retina and anterior neural fold homeobox".
  6. 1 2 Muranishi Y, Terada K, Furukawa T (Apr 2012). "An essential role for Rax in retina and neuroendocrine system development". Development, Growth & Differentiation. 54 (3): 341–8. doi:10.1111/j.1440-169X.2012.01337.x. PMID   22524605. S2CID   20066919.
  7. 1 2 Carlson BM (2014). "Sense Organs". Human Embryology and Developmental Biology (5th ed.). Elsevier/Saunders. pp. 270–71. ISBN   978-1-4557-2794-0.
  8. Furukawa T, Kozak CA, Cepko CL (Apr 1997). "rax, a novel paired-type homeobox gene, shows expression in the anterior neural fold and developing retina". Proceedings of the National Academy of Sciences of the United States of America. 94 (7): 3088–93. Bibcode:1997PNAS...94.3088F. doi: 10.1073/pnas.94.7.3088 . PMC   20326 . PMID   9096350.
  9. Mathers PH, Grinberg A, Mahon KA, Jamrich M (Jun 1997). "The Rx homeobox gene is essential for vertebrate eye development". Nature. 387 (6633): 603–7. Bibcode:1997Natur.387..603M. doi:10.1038/42475. PMID   9177348. S2CID   4284692.
  10. Voronina VA, Kozhemyakina EA, O'Kernick CM, Kahn ND, Wenger SL, Linberg JV, Schneider AS, Mathers PH (Feb 2004). "Mutations in the human RAX homeobox gene in a patient with anophthalmia and sclerocornea". Human Molecular Genetics. 13 (3): 315–22. doi: 10.1093/hmg/ddh025 . PMID   14662654.
  11. Fish MB, Nakayama T, Fisher M, Hirsch N, Cox A, Reeder R, Carruthers S, Hall A, Stemple DL, Grainger RM (Nov 2014). "Xenopus mutant reveals necessity of rax for specifying the eye field which otherwise forms tissue with telencephalic and diencephalic character". Developmental Biology. 395 (2): 317–330. doi:10.1016/j.ydbio.2014.09.004. PMC   4267880 . PMID   25224223.
  12. 1 2 Furutani-Seiki M, Wittbrodt J (2004-07-01). "Medaka and zebrafish, an evolutionary twin study". Mechanisms of Development. 121 (7): 629–637. doi:10.1016/j.mod.2004.05.010. ISSN   0925-4773. PMID   15210172. S2CID   1798545.
  13. Loosli F, Staub W, Finger-Baier KC, Ober EA, Verkade H, Wittbrodt J, Baier H (2003-09-01). "Loss of eyes in zebrafish caused by mutation of chokh/rx3". EMBO Reports. 4 (9): 894–899. doi:10.1038/sj.embor.embor919. ISSN   1469-221X. PMC   1326357 . PMID   12947416.

This article incorporates text from the United States National Library of Medicine, which is in the public domain.