FUNCTIONAL IDENTIFICATION OF TRANSCRIPTION CONTROL SEQUENCES OF THE MOUSE CRRY GENE

The mouse C receptor-related gene Crry is expressed by a wide variety of cells. Those sequences required for the transcriptional control of this gene were identified by deletion analysis of regions 5' of the in itiating ATG. Fusion of Crry promoter sequences to the reporter gene C AT identified a region approximately 1500 bp upstream of the transcrip tional start site that enhanced transcription of this gene construct. Gel shift and methylation interference assays were performed, and a sp ecific protein-DNA complex was identified within this region. These as says defined a 16-bp sequence 1642 bp 5' of the initiating ATG that bo und a protein in nuclear extracts prepared from all murine cell lines and tissues examined. The methylation interference assay indicated tha t the core region of the DNA sequence recognized by the protein was GG AA, the common core binding site for the ets family of proto-oncogenes . Oligonucleotides prepared from this sequence with the GGAA sequence did inhibit the DNA/protein complex formation, whereas those with a mu tant GGAA sites did not. The minimal site identified by methylation in terference was able to up-regulate transcription when placed downstrea m of a heterologous promoter, whereas the same sequence with an altere d GGAA site could not. Thus, this site functions as an enhancer.