Hox genes play a fundamental role in the development of the vertebrate central nervous system, heart, axial skeleton, limbs, gut, urogenital tract and external genitalia. The homeobox gene HoxA1 is transcriptionally regulated by retinoic acid (RA) and encodes a transcription factor which has been shown to play important roles in cell differentiation and embryogenesis. HoxA1 is also expressed in cancers, such as mammary tumors, though it is not expres-sed in normal gland or in precancerous mammary tissues. At embryonic stages, HoxA2 is expressed in the mesenchyme and epithelial cells of the palate, however its expression is restricted to the tips of the growing palatal shelves. HoxA2 protein is predominantly expressed in the nuclei of cells in the ventral mantle region of the developing embryo. In the developing and adult mouse spinal cord, HoxA2 protein may contribute to dorsal-ventral patterning and/or to the specification of neuronal phenotype. HoxA7 functions as a potent transcriptional repressor and its action as such requires several domains, including both activator and repressor regions. HoxA7 is expressed in the fetal liver, lung, skeletal muscle, kidney, pancreas and placenta.
Function:
Sequence-specific transcription factor which is part of a developmental regulatory system that provides cells with specific positional identities on the anterior-posterior axis. Acts on the anterior body structures. Seems to act in the maintenance and/or generation of hindbrain segments.
Subcellular Location:
Nucleus.
DISEASE:
Defects in HOXA1 are the cause of Athabaskan brainstem dysgenesis syndrome (ABDS) [MIM:601536]; also known as Narvajo brainstem syndrome. This syndrome is characterized by horizontal gaze palsy, sensorineural deafness, central hypoventilation, and developmental delay. Some patients had swallowing dysfunction, vocal cord paralysis, facial paresis, seizures, and cardiac outflow tract anomalies.
Defects in HOXA1 are the cause of Bosley-Salih-Alorainy syndrome (BSAS) [MIM:601536]. Affected individuals show horizontal gaze abnormalities, deafness, facial weakness, vascular malformations of the internal carotid arteries and cardiac outflow trac. Some patients manifest mental retardation and autism spectrum disorder. In contrast to individuals with ABSD, central hypoventilation is not observed in individuals with BSAS.
Similarity:
Belongs to the Antp homeobox family. Labial subfamily.
Contains 1 homeobox DNA-binding domain.
SWISS:
P49639
Gene ID:
3198
Database links:
Entrez Gene: 3198 Human
Entrez Gene: 15394 Mouse
Entrez Gene: 25607 Rat
Omim: 142955 Human
SwissProt: P49639 Human
SwissProt: P09022 Mouse
SwissProt: O08656 Rat
Unigene: 67397 Human
Unigene: 197 Mouse
Unigene: 228589 Rat
Unigene: 9780 Rat
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