Two distinct subgroups of Group B Sox genes for transcriptional activatorsand repressors: their expression during embryonic organogenesis of the chicken

Citation
M. Uchikawa et al., Two distinct subgroups of Group B Sox genes for transcriptional activatorsand repressors: their expression during embryonic organogenesis of the chicken, MECH DEVEL, 84(1-2), 1999, pp. 103-120
Citations number
41
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Cell & Developmental Biology
Journal title
MECHANISMS OF DEVELOPMENT
ISSN journal
0925-4773 → ACNP
Volume
84
Issue
1-2
Year of publication
1999
Pages
103 - 120
Database
ISI
SICI code
0925-4773(199906)84:1-2<103:TDSOGB>2.0.ZU;2-H
Abstract
Group B Sox genes, Sox-1, -2 and -3 are known to activate crystallin genes and to be involved in differentiation of lens and neural tissues. Screening of chicken genomic sequences for more Group B Sos genes identified two add itional genes, Sox14 and Sox21. Proteins encoded by Sox14 and Sox21 genes a re similar to each other but distinct from those coded by Sox1-3 (subgroup B1) except for the HMG domain and Group B homology immediately C-proximal o f the HMG domain. C-terminal domains of SOX21 and SOX14 proteins function a s strong and weak repression domains, respectively, when linked to the GAL4 DNA binding domain. These SOX proteins strongly (SOX21) or moderately (SOX 14) inhibited activation of delta 1-crystallin DC5 enhancer by SOX1 or SOX2 , establishing that Sox14 and Sox21 are repressing subgroup (B2) of Group B Sox genes. Phis provides the first evidence for the occurrence of represso r SOX proteins. Activating (B1) and repressing (B2) subgroups of Group B So x genes display interesting overlaps of expression domains in developing ti ssues (e.g. optic tectum, spinal cord, inner ear, alimentary tract. branchi al arches). Within each subgroup, most expression domains of Sox1 and -3 ar e included in those of Sox2 (e.g. CNS, PNS, inner ear), while co-expression of Sox14 and Sox21 occurs in highly restricted sites of the CNS, with the likely temporal order of Sox21 preceding Sox14 (e.g. interneurons of the sp inal cord). These expression patterns suggest that target genes of Group B SOX proteins are finely regulated by the counterbalance of activating and r epressing SOX proteins. (C) 1999 Elsevier Science Ireland Ltd. All rights r eserved.