Biology:HOXA3
 Generic protein structure example |
Homeobox protein Hox-A3 is a protein that in humans is encoded by the HOXA3 gene.[1][2][3]
Function
In vertebrates, the genes encoding the class of transcription factors called homeobox genes are found in clusters named A, B, C, and D on four separate chromosomes. Expression of these proteins is spatially and temporally regulated during embryonic development. This gene is part of the A cluster on chromosome 7 and encodes a DNA-binding transcription factor which may regulate gene expression, morphogenesis, and differentiation. Three transcript variants encoding two different isoforms have been found for this gene.[3]
During normal fetal development, HoxA3 is expressed in mesenchymal neural crest cells and endodermal cells found in the third pharyngeal pouch.[4] Expression of HoxA3 in these cells affects the proper formation of the thymus, thyroid, and parathyroid organs.[5][6] While the gene does not seem to affect the proliferation or migration of the pharyngeal neural crest cells, it does appear to trigger cellular differentiation events required to form these organs.[5] Knockout of HoxA3 leads to failure in forming the thymus (athymia) and parathyroid gland (aparthyroidism).[6] Mutant HoxA3 also causes a reduction in thyroid size. While the follicular and parafollicular cells still differentiate, their numbers are reduced and they are not evenly distributed throughout the gland.[5] Mutant HoxA3 models show similar phenotypes as those seen in DiGeorge’s Syndrome, and it is possible that the two are linked.[5]
Regulation
The HOXA3 gene is repressed by the microRNA miR-10a.[7]
See also
References
- ↑ "Nomenclature for human homeobox genes". Genomics 7 (3): 460. July 1990. doi:10.1016/0888-7543(90)90186-X. PMID 1973146.
- ↑ "Vertebrate homeobox gene nomenclature". Cell 71 (4): 551–3. November 1992. doi:10.1016/0092-8674(92)90588-4. PMID 1358459.
- ↑ 3.0 3.1 "Entrez Gene: HOXA3 homeobox A3". https://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=3200.
- ↑ "A distinct Hox code for the branchial region of the vertebrate head". Nature 353 (6347): 861–4. October 1991. doi:10.1038/353861a0. PMID 1682814. Bibcode: 1991Natur.353..861H.
- ↑ 5.0 5.1 5.2 5.3 "The role of Hoxa-3 in mouse thymus and thyroid development". Development 121 (7): 1989–2003. July 1995. doi:10.1242/dev.121.7.1989. PMID 7635047.
- ↑ 6.0 6.1 "Multiple roles for HOXA3 in regulating thymus and parathyroid differentiation and morphogenesis in mouse". Development 141 (19): 3697–708. October 2014. doi:10.1242/dev.110833. PMID 25249461.
- ↑ "DNA methylation regulates MicroRNA expression". Cancer Biology & Therapy 6 (8): 1284–8. August 2007. doi:10.4161/cbt.6.8.4486. PMID 17660710.
Further reading
- "Fine mapping of human HOX gene clusters". Cytogenetics and Cell Genetics 73 (1–2): 114–5. 1996. doi:10.1159/000134320. PMID 8646877.
- "Normalization and subtraction: two approaches to facilitate gene discovery". Genome Research 6 (9): 791–806. September 1996. doi:10.1101/gr.6.9.791. PMID 8889548.
- "Hox group 3 paralogs regulate the development and migration of the thymus, thyroid, and parathyroid glands". Developmental Biology 195 (1): 1–15. March 1998. doi:10.1006/dbio.1997.8827. PMID 9520319.
- Sanger Centre, The; Washington University Genome Sequencing Cente, The (November 1998). "Toward a complete human genome sequence". Genome Research 8 (11): 1097–108. doi:10.1101/gr.8.11.1097. PMID 9847074.
- "Retinoic acid-induced thymic abnormalities in the mouse are associated with altered pharyngeal morphology, thymocyte maturation defects, and altered expression of Hoxa3 and Pax1". Teratology 58 (6): 263–75. December 1998. doi:10.1002/(SICI)1096-9926(199812)58:6<263::AID-TERA8>3.0.CO;2-A. PMID 9894676.
- "Krox20 and kreisler co-operate in the transcriptional control of segmental expression of Hoxb3 in the developing hindbrain". The EMBO Journal 21 (3): 365–76. February 2002. doi:10.1093/emboj/21.3.365. PMID 11823429.
- "Complete mutation analysis panel of the 39 human HOX genes". Teratology 65 (2): 50–62. February 2002. doi:10.1002/tera.10009. PMID 11857506.
- "Mapping DNA-protein interactions in large genomes by sequence tag analysis of genomic enrichment". Nature Methods 2 (1): 47–53. January 2005. doi:10.1038/nmeth726. PMID 15782160.
- "The high-mobility-group domain of Sox proteins interacts with DNA-binding domains of many transcription factors". Nucleic Acids Research 34 (6): 1735–44. 2006. doi:10.1093/nar/gkl105. PMID 16582099.
External links
- HOXA3+protein,+human at the US National Library of Medicine Medical Subject Headings (MeSH)
This article incorporates text from the United States National Library of Medicine, which is in the public domain.
 |  |
