Farashi S, Azad M, Bayat H, Banan M, Mohammad Parast S and Ohadi M
Posters-Accepted Abstracts: Biol Syst Open Access
We have previously reported a human-specific nucleotide in the promoter sequence of the calreticulin (CALR) gene at position -220C, which is the site of action of valproic acid. Reversion of this nucleotide to the ancestral type, -220A co-occurs with severe deficit in higher brain cognitive functions. This mutation has since been reported in the 1000 genomes database at an approximate frequency of 0.0009 in humans (rs138452745). In the current study, we compare the pattern of protein binding between -220C and -220A using electrophoretic mobility shift assay (EMSA) by oligonucleotide probes representing 24 base pairs encompassing -220C>A. Antibodies reactive against transcription factors CREB, USF and c-Myc were used to identify the specific proteins involved in complexes with DNA. Significant increase was observed in the overall protein complexes binding to the -220C allele vs. -220A. The transcription factors, CREB, USF, and c-Myc, were differentially bound to -220C represented by super shifts. We propose that differential binding of CREB, USF and c-Myc to CALR nucleotide -220C may be linked with the evolution of higher brain functions in human.
