Regulatory elements in the rat betaB2-crystallin promoter.
The suggested common regulator of the eye lens crystallin genes is c-Maf. Maf responsive elements have been detected in a number of crystallin promoters including that of the rat betaB2-crystallin gene. The betaB2-crystallin gene is active in the post-natal lens and its mRNA reaches its maximal level in the rat lens 6 months after birth. Yet c-Maf has been reported to be present in the rat lens only up to 3 months of age. This discrepancy prompted an investigation into the role of the Maf responsive element (MARE) in the regulation of activity of the rat betaB2-crystallin promoter in rat lens fiber cells. Although betaB2 promoter activity is enhanced by c-Maf in both in vitro differentiating rat lens fiber cells and CHO cells, deletion of the betaB2 MARE, which was mapped to -143/-123, does not decrease betaB2 promoter activity in lens fiber cells. Furthermore, a dominant negative c-Maf construct did not inhibit activity of the betaB2 promoter in lens fiber cells. The data suggest that the betaB2 MARE does not play a major role in regulating activity of the betaB2 promoter. Rather, a putative Sox binding site at -164/-159 and a positive element at -14/-7 seem to be the prime regulatory elements.
Doerwald
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L
Department of Biochemistry, Faculty of Science, University of Nijmegen, 6500 HB Nijmegen, The Netherlands.
Nijveen
H
H
Civil
A
A
van Genesen
S T
ST
Lubsen
N H
NH
D000818:Animals; D002454:Cell Differentiation; D003459:Crystallins / Q000235:genetics*; D004847:Epithelial Cells / Q000166:cytology; D005656:Fungal Proteins / Q000235:genetics; D015870:Gene Expression; D005809:Genes, Regulator / Q000502:physiology*; D017930:Genes, Reporter / Q000502:physiology; D007908:Lens, Crystalline / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000502:physiology*; D051381:Rats; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D014162:Transfection / Q000379:methods
D003459:Crystallins; D005656:Fungal Proteins; C104954:MAF1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors