HOXA3

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

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)[1] Band 7p15.2 Start 27,106,184 bp[1] End 27,152,581 bp[1]
Gene location (Mouse) Chr. Chromosome 6 (mouse)[2] Band 6 B3|6 25.4 cM Start 52,146,042 bp[2] End 52,190,316 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) 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 BioGPS 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 Species Human Mouse Entrez 3200 15400 Ensembl ENSG00000105997 ENSMUSG00000079560 UniProt O43365 P02831 RefSeq (mRNA) NM_030661 NM_153631 NM_153632 NM_010452 RefSeq (protein) NP_109377 NP_705895 NP_034582 Location (UCSC) Chr 7: 27.11 – 27.15 Mb Chr 6: 52.15 – 52.19 Mb PubMed search [3] [4]
Wikidata
View/Edit Human View/Edit Mouse

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]

See also

• Homeobox