HOXA3

HOXA3
Identifiers
Aliases	HOXA3, HOX1, HOX1E, homeobox A3
External IDs	OMIM: 142954; MGI: 96175; HomoloGene: 40725; GeneCards: HOXA3; OMA:HOXA3 - orthologs
Gene location (Human)
Chr.	Chromosome 7 (human)
End	27,152,581 bp
Gene location (Mouse)
Chr.	Chromosome 6 (mouse)
End	52,190,316 bp
RNA expression pattern
	Top expressed in
	caput epididymis; ; corpus epididymis; ; right uterine tube; ; left uterine tube; ; parietal pleura; ; renal medulla; ; tibia; ; Descending thoracic aorta; ; visceral pleura; ; gastric mucosa;
	Top expressed in
	ascending aorta; ; aortic valve; ; tail of embryo; ; tunica albuginea of testis; ; thoracic vertebral column; ; thyroid gland; ; lumbar subsegment of spinal cord; ; genital tubercle; ; rete testis; ; left lung lobe;
	More reference expression data
	More reference expression data
Gene ontology
Molecular function	sequence-specific DNA binding; DNA binding; DNA-binding transcription factor activity; HMG box domain binding; protein binding; DNA-binding transcription factor activity, RNA polymerase II-specific; RNA polymerase II cis-regulatory region sequence-specific DNA binding;
Cellular component	nucleoplasm; nucleus;
Biological process	embryonic skeletal system morphogenesis; glossopharyngeal nerve morphogenesis; regulation of transcription, DNA-templated; thymus development; transcription, DNA-templated; embryonic skeletal system development; multicellular organism development; animal organ formation; blood vessel remodeling; thyroid gland development; cartilage development; parathyroid gland development; angiogenesis; positive regulation of cell population proliferation; animal organ morphogenesis; specification of animal organ position; anterior/posterior pattern specification; regulation of transcription by RNA polymerase II; calcium ion transport; gene expression; magnesium ion homeostasis; bone mineralization; negative regulation of calcium ion transport; phosphate ion homeostasis; calcium ion homeostasis; positive regulation of receptor binding; positive regulation of transcription by RNA polymerase II;
	Sources:Amigo / QuickGO
Orthologs
	3200
	15400
	ENSG00000105997
	ENSMUSG00000079560
	O43365
	P02831
	NM_030661; NM_153631; NM_153632
	NM_010452
	NP_109377; NP_705895
	NP_034582
	Wikidata
View/Edit Human	View/Edit Mouse

Homeobox protein Hox-A3 is a protein that in humans is encoded by the HOXA3 gene.^[5]^[6]^[7]

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.^[7]

During normal fetal development, HoxA3 is expressed in mesenchymal neural crest cells and endodermal cells found in the third pharyngeal pouch.^[8] Expression of HoxA3 in these cells affects the proper formation of the thymus, thyroid, and parathyroid organs.^[9]^[10] 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.^[9] Knockout of HoxA3 leads to failure in forming the thymus (athymia) and parathyroid gland (aparthyroidism).^[10] 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.^[9] Mutant HoxA3 models show similar phenotypes as those seen in DiGeorge's syndrome, and it is possible that the two are linked.^[9]

Regulation

The HOXA3 gene is repressed by the microRNA miR-10a.^[11]

References

^ ^a ^b ^c GRCh38: Ensembl release 89: ENSG00000105997 – Ensembl, May 2017
^ ^a ^b ^c GRCm38: Ensembl release 89: ENSMUSG00000079560 – Ensembl, May 2017
^ "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
^ "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
^ McAlpine PJ, Shows TB (July 1990). "Nomenclature for human homeobox genes". Genomics. 7 (3): 460. doi:10.1016/0888-7543(90)90186-X. PMID 1973146.
^ Scott MP (November 1992). "Vertebrate homeobox gene nomenclature". Cell. 71 (4): 551–3. doi:10.1016/0092-8674(92)90588-4. PMID 1358459. S2CID 13370372.
^ ^a ^b "Entrez Gene: HOXA3 homeobox A3".
^ Hunt P, Gulisano M, Cook M, Sham MH, Faiella A, Wilkinson D, et al. (October 1991). "A distinct Hox code for the branchial region of the vertebrate head". Nature. 353 (6347): 861–4. Bibcode:1991Natur.353..861H. doi:10.1038/353861a0. PMID 1682814. S2CID 4312466.
^ ^a ^b ^c ^d Manley NR, Capecchi MR (July 1995). "The role of Hoxa-3 in mouse thymus and thyroid development". Development. 121 (7): 1989–2003. doi:10.1242/dev.121.7.1989. PMID 7635047.
^ ^a ^b Chojnowski JL, Masuda K, Trau HA, Thomas K, Capecchi M, Manley NR (October 2014). "Multiple roles for HOXA3 in regulating thymus and parathyroid differentiation and morphogenesis in mouse". Development. 141 (19): 3697–708. doi:10.1242/dev.110833. PMC 4197593. PMID 25249461.
^ Han L, Witmer PD, Casey E, Valle D, Sukumar S (August 2007). "DNA methylation regulates MicroRNA expression". Cancer Biology & Therapy. 6 (8): 1284–8. doi:10.4161/cbt.6.8.4486. PMID 17660710.