The role of ARX in cortical development.
The ARX protein (encoded by the aristaless-related homeobox gene) is a member of the paired class of homeoproteins. More precisely, it is a member of the Aristaless subclass of proteins with a glutamine residue (Q) at the critical position 50 of the homeodomain (Q50). Through identification of diverse inherited or de novo mutations, genetic investigations of X-linked mental retardation conditions have demonstrated the implication of ARX in a wide spectrum of disorders extending from phenotypes with severe neuronal migration defects, such as lissencephaly, to mild forms of X-linked mental retardation without apparent brain abnormalities. These investigations have recently directed attention to the role of this gene in brain development. Analysis of its spatiotemporal localization profile have revealed expression mainly in telencephalic structures at all stages of development. Interestingly, in adult, ARX expression becomes restricted to a population of GABAergic neurons. Although the identification of the target genes regulated by ARX remains a crucial step to better understanding its role during brain development, studies of the role of ARX orthologs in different models have indicated that it is essential for important developmental processes such as proliferation, cell differentiation and neuronal migration.
Friocourt
Gaëlle
G
Department of Anatomy and Developmental Biology, University College London, London WC1E 6BT, UK.
Poirier
Karine
K
Rakić
Sonja
S
Parnavelas
John G
JG
Chelly
Jamel
J
D000818:Animals; D002540:Cerebral Cortex / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism; D015870:Gene Expression; D018507:Gene Expression Regulation, Developmental / Q000235:genetics*; D018398:Homeodomain Proteins / Q000235:genetics* / Q000502:physiology; D006801:Humans; D009154:Mutation; D014157:Transcription Factors / Q000502:physiology*
C469264:ARX protein, human; D018398:Homeodomain Proteins; D014157:Transcription Factors