High impact information on SOX2

• A previously unreported case with severe bilateral microphthalmia and oesophageal atresia has a de novo missense mutation, R74P, that alters a highly evolutionarily conserved residue within the high mobility group domain, which is critical for DNA-binding of SOX2 [1].
• Thus, Wnt and FGF signals converge to activate Sox2 expression through the enhancer N-1c, revealing the direct involvement of the Wnt signal in the initiation of neural plate development [2].
• DC5 contains PAX6 and SOX2 binding sites, and its activity depends on the cooperative binding of these two transcription factors [3].
• Thus, an essential molecular event in lens induction is the 'turning on' of the transcriptional regulators SOX2/3 in the Pax6-expressing ectoderm and these SOX proteins activate crystallin gene expression [4].
• The host epiblast forms a non-regionalized neural tube, which expresses the pan-neural marker SOX-2 (a Sry-related transcription factor) but not any region-specific markers for the forebrain, hindbrain or spinal cord [5].

Biological context of SOX2

• Expression of Sox2, which encodes an HMG-box-type transcription factor, is down-regulated in the neural plate when neural crest segregates from dorsal neural tube and remains low during crest cell migration [6].
• We also observed that L-Maf and Sox2 cooperatively enhanced the transactivation of a reporter gene bearing the delta-crystallin enhancer in ovo, implying that L-Maf and Sox2 can induce delta-crystallin through the same enhancer [7].

Anatomical context of SOX2

• Multiple roles of Sox2, an HMG-box transcription factor in avian neural crest development [6].
• Sox2 expression is subsequently up-regulated in some crest-derived cells in the developing peripheral nervous system and is later restricted to glial sublineages [6].
• However, neither the hypoblast nor any of these factors or combinations thereof can induce the definitive neural marker Sox2 or the formation of a mature neural plate or a forebrain, suggesting that the hypoblast is not a head organizer and that other signals remain to be identified [8].
• Region-specific expression of chicken Sox2 in the developing gut and lung epithelium: regulation by epithelial-mesenchymal interactions [9].
• Although Sox2 expression in the early embryonic CNS appears uniform, it is actually pieced together by five separate enhancers with distinct spatio-temporal specificities, including the one activated by the neural induction signals emanating from Hensen's node [10].

Other interactions of SOX2

• Embryonic expression of the chicken Sox2, Sox3 and Sox11 genes suggests an interactive role in neuronal development [11].
• Dynamic expression of chicken Sox2 and Sox3 genes in ectoderm induced to form neural tissue [12].
• This gene is a member of the subgroup B, which includes Sox1, Sox2 and Sox3 [13].
• Neural plate and sensory placodes share the expression of N-cadherin and Group B1 Sox genes, represented by Sox2 [14].

Analytical, diagnostic and therapeutic context of SOX2

• To identify regulatory sequences for Sox2 expression governing early neurogenesis, we scanned the 50-kb region of the chicken Sox2 locus for enhancer activity utilizing embryo electroporation, resulting in identification of a number of enhancers scattered throughout the analyzed genomic span [15].

References