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Binding of a factor to an enhancer element responsible for the tissue specific expression of the chicken αA-crystallin gene

1991; The Company of Biologists; Volume: 113; Issue: 2 Linguagem: Inglês

10.1242/dev.113.2.539

1477-9129

Isao Matsuo, Masahi Kitamura, Kenji Okazaki, Kunio Yasuda,

RNA regulation and disease

ABSTRACT We have characterized a regulatory region of the chicken αA-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 αA-crystallin or β-actin basal promoters fused to the CAT gene. In vivo competition experiments demonstrated that DNA sequences containing the 84 bp element reduced αA-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 61000 Mr (61×103Mr) lens nuclear protein exhibited DNA-binding activity specific to the 84 bp element. Our data suggested that the 61×103Mr nuclear protein, and the 84 bp element that it interacts with, may be involved in regulating the αA-crystallin gene expression in vivo.