POU domain factors of the Brn-3 class recognize functional DNA elements which are distinctive, symmetrical, and highly conserved in evolution.

AUTOR(ES)

Gruber, C A

RESUMO

To better understand the diversity of function within the POU domain class of transcriptional regulators, we have determined the optimal DNA recognition site of several proteins of the POU-IV (Brn-3) subclass by random oligonucleotide selection. The consensus recognition element derived in this study, ATAATTAAT, is clearly distinct from octamer sites described for the POU factor Oct-1. The optimal POU-IV site determined here also binds Brn-3.0 with significantly higher affinity than consensus recognition sites previously proposed for this POU subclass. The binding affinity of Brn-3.0 on its optimal site, several variants of this site, and several naturally occurring POU recognition elements is highly correlated with the activation of reporter gene expression by Brn-3.0 in transfection assays. The preferred DNA recognition site of Brn-3.0 resembles strongly the optimal sites of another mammalian POU-IV class protein, Brn-3.2, and of the Caenorhabditis elegans Brn-3.0 homolog Unc-86, demonstrating that the site-specific DNA recognition properties of these factors are highly conserved between widely divergent species.

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