Activation and repression sequences determine the lens-specific expression of the rat γD-crystallin gene

• Published in: Nucleic acids research Vol. 20; no. 18; pp. 4865 - 4872
• Main Authors: Peek, Ron, Kraft, Harry J., Klok, Erik J., Lubsen, Nicolette H., Schoenmakers, John G.G.
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 25.09.1992
• Subjects: Animals; Base Sequence; Biological and medical sciences; Cell Nucleus - metabolism; Chloramphenicol O-Acetyltransferase - genetics; Chloramphenicol O-Acetyltransferase - metabolism; Crystallins - genetics; DNA - genetics; DNA - isolation & purification; Epithelium - physiology; Fundamental and applied biological sciences. Psychology; Lens, Crystalline - physiology; Molecular and cellular biology; Molecular genetics; Molecular Sequence Data; Nuclear Proteins - metabolism; Oligodeoxyribonucleotides; Promoter Regions, Genetic; Rats; Recombinant Fusion Proteins - metabolism; Restriction Mapping; Transcription. Transcription factor. Splicing. Rna processing; Proteins; Vertebrata; Mammalia; Crystallin; Gene; Rat; Transcription; Rodentia; Tissue specificity; Trans acting regulatory factor; Regulatory sequence; Lens
• ISSN: 0305-1048; 1362-4962
• DOI: 10.1093/nar/20.18.4865

Rat lens nuclear extracts contain a factor that binds to position -57 to -46 of the rat γD-crystallin promoter region. This factor protects the sequence 5′-CTGCCAA- CGCAG-3′ in a footprint analysis. Binding to this region Is crucial for maximal promoter activity In rat lens cells, but this sequence was unable to act as an enhancer when cloned in front of a heterologous promoter. A region directly upstream from this activating sequence, between posItion -85 to -67, acts as a strong silencer of promoter activity in non-lens cells. This silencing effect is mediated by trans-acting factor(s). Our data provide evidence for two regulatory elements In rat γD-crystallin gene expression, an activating sequence active in lens cells and a silencing sequence active only In non-lens cells. The factor that binds to the activating sequence could be detected only in lens cells and may be a determinant of the lens-specific expression of the γ-crystallin genes.