Distal Sox binding elements of the alphaB-crystallin gene show lens enhancer activity in transgenic mouse embryos.
alphaB-Crystallin, a member of the small heat shock protein (sHSP) family, is expressed in various tissues including lens, heart, and skeletal muscle. Previously we identified the gene of HSPB2, another member of the sHSP family, located 1-kb upstream of the alphaB-crystallin gene in a head-to-head manner. In the present study, we found a highly conserved region of 220 bp approximately 2.4-kb upstream of the alphaB-crystallin gene and examined its role in expression of the alphaB-crystallin gene. Transgenic mice containing 3 kb of the upstream sequence of the alphaB-crystallin gene showed lacZ reporter gene expression in the lens as well as the myotome and heart on embryonic day 12.5. Deletion analysis revealed that the -2656/-2267 region including the conserved region with four putative Sox binding elements (E1-E4) exhibits lens enhancer activity toward the alphaB-crystallin promoter. Gel shift assays showed that the Sox1 and Sox2 proteins preferentially bound to E2 and E4. Moreover, disruption of E2 and E4 abolished the reporter gene expression in the lens. These results indicate that the newly identified enhancer with Sox elements activates the alphaB-crystallin promoter in the lens, although they are separated by the entire HSPB2 gene.
Ijichi
Nobuhiro
N
Division of Disease Genes, Research Center for Genetic Information, Medical Institute of Bioregulation, Kyushu University, Maidashi 3-1-1, Higashi-ku, Fukuoka 812-8582.
Tsujimoto
Naomi
N
Iwaki
Toru
T
Fukumaki
Yasuyuki
Y
Iwaki
Akiko
A
D000818:Animals; D001483:Base Sequence; D017124:Conserved Sequence / Q000235:genetics; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004622:Embryo, Mammalian / Q000378:metabolism*; D004742:Enhancer Elements, Genetic / Q000235:genetics*; D018507:Gene Expression Regulation, Developmental; D017930:Genes, Reporter / Q000235:genetics; D024002:HMGB Proteins; D055551:HSP27 Heat-Shock Proteins; D006360:Heat-Shock Proteins / Q000235:genetics; D006609:High Mobility Group Proteins / Q000378:metabolism*; D007908:Lens, Crystalline / Q000196:embryology / Q000378:metabolism*; D051379:Mice; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000378:metabolism*; D011485:Protein Binding; D020218:Response Elements / Q000235:genetics; D055748:SOXB1 Transcription Factors; D014157:Transcription Factors; D038203:alpha-Crystallin B Chain / Q000235:genetics*
D004268:DNA-Binding Proteins; D024002:HMGB Proteins; D055551:HSP27 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D006609:High Mobility Group Proteins; C486699:Hspb2 protein, mouse; D009687:Nuclear Proteins; D055748:SOXB1 Transcription Factors; C098693:Sox1 protein, mouse; C527783:Sox2 protein, mouse; D014157:Transcription Factors; D038203:alpha-Crystallin B Chain