Pax-6 and lens-specific transcription of the chicken delta 1-crystallin gene

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 92; no. 10; pp. 4681 - 4685
• Main Authors: Cvekl, A, Sax, C M, Li, X, McDermott, J B, Piatigorsky, J
• Format: Journal Article
• Language: English
• Published: United States National Acad Sciences 09-05-1995
• Subjects: Animals; Base Sequence; beta-Galactosidase - biosynthesis; Binding Sites; Chick Embryo; Chickens; Chloramphenicol O-Acetyltransferase - biosynthesis; Cloning, Molecular; Crystallins - biosynthesis; DNA-Binding Proteins - biosynthesis; DNA-Binding Proteins - metabolism; Enhancer Elements, Genetic; Epithelium - metabolism; Eye Proteins; Fibroblasts - metabolism; Gene Expression; Guinea Pigs; Homeodomain Proteins; Lens, Crystalline - metabolism; Mice; Molecular Sequence Data; Oligodeoxyribonucleotides; Organ Specificity; Paired Box Transcription Factors; PAX6 Transcription Factor; Recombinant Proteins - biosynthesis; Repressor Proteins; Sequence Homology, Nucleic Acid; Transcription Factors - metabolism; Transcription, Genetic; Transfection
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.92.10.4681

The abundance of delta-crystallin in the chicken eye lens provides an advantageous marker for tissue-specific gene expression during cellular differentiation. The lens-specific expression of the delta 1-crystallin gene is governed by an enhancer in the third intron, which binds a positive (delta EF2) and negative (delta EF1) factor in its core region. Here we show by DNase I footprinting, electrophoretic mobility-shift assays, and cotransfection experiments with the delta 1-promoter/enhancer fused to the chloramphenicol acetyltransferase reporter gene that the delta 1-crystallin enhancer has two adjacent functional Pax-6 binding sites. We also demonstrate by DNase I footprinting that the delta EF1 site can bind the transcription factor USF, raising the possibility that USF may cooperate with Pax-6 in activation of the chicken delta 1- and alpha A-crystallin genes. These data, coupled with our recent demonstration that Pax-6 activates the alpha A-crystallin gene, suggest that Pax-6 may have been used extensively throughout evolution to recruit and express crystallin genes in the lens.