Binding of a factor to an enhancer element responsible for the tissue-specific expression of the chicken alpha A-crystallin gene.
We have characterized a regulatory region of the chicken alpha A-crystallin gene using transfection assays, which revealed that a 84 base pair element (-162 to -79) in the 5' flanking sequence is necessary and sufficient for lens-specific expression. A multimer of this element functions as lens-specific enhancer and synergistically activates transcription from chicken alpha A-crystallin or beta-actin basal promoters fused to the CAT gene. In vivo competition experiments demonstrated that DNA sequences containing the 84 bp element reduced alpha A-crystallin-CAT fusion gene expression. A nuclear factor present exclusively in lens cells binds to the 84 bp element in the region between positions -165 and -140. Southwestern blot analysis showed that 61,000 Mr (61 x 10(3) Mr) lens nuclear protein exhibited DNA-binding activity specific to the 84 bp element. Our data suggested that the 61 x 10(3) Mr nuclear protein, and the 84 bp element that it interacts with, may be involved in regulating the alpha A-crystallin gene expression in vivo.
Matsuo
I
I
Department of Biophysics, Faculty of Science, Kyoto University, Japan.
Kitamura
M
M
Okazaki
K
K
Yasuda
K
K
D000818:Animals; D002642:Chick Embryo; D003459:Crystallins / Q000235:genetics*; D004247:DNA / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics; D004742:Enhancer Elements, Genetic / Q000235:genetics; D015870:Gene Expression / Q000502:physiology*; D005786:Gene Expression Regulation / Q000502:physiology*; D007908:Lens, Crystalline / Q000196:embryology*; D010957:Plasmids; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics; D014158:Transcription, Genetic / Q000502:physiology*; D014162:Transfection
D003459:Crystallins; D004268:DNA-Binding Proteins; D004247:DNA