IDENTIFICATION OF THE CONTACT SITES OF A FACTOR THAT INTERACTS WITH MOTIF I (ALPHA-CE1) OF THE CHICKEN ALPHA-A-CRYSTALLIN LENS-SPECIFIC ENHANCER

A lens-specific enhancer, an 84bp element between base pairs -162 and -79, of the chicken αA-crystallin gene is composed of two motifs, αCE1 (- 162 and -134) and αCE2 (-119 and -99). Previous studies showed that a nuclear factor which binds to αCE1, termed αCEF1, is present at high levels in lens cells. Methylation interference analysis identified an inverted repeat of 5bp separated by 4bp, 5′-CTGGTTCCCACCAG-3′, between positions -153 and -140 as an αCEF1-binding site. Gel mobility shift assays using synthetic oligonucleotides with site-directed mutations revealed that the αCEF1-binding consensus sequence is 5′-C( T A)GGN6CC( A T)G-3′. Comparison of this binding motif with regulatory sequences of diverse crystallin genes from diverse species suggests that αCE1 may be a ubiquitous crystallin gene enhancer. © 1992.