Title

Sequences flanking the E-box contribute to cooperative binding by c-Myc/Max heterodimers to adjacent binding sites

UMMS Affiliation

Program in Gene Function and Expression; Program in Molecular Medicine

Date

6-6-1998

Document Type

Article

Medical Subject Headings

Animals; Base Sequence; Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; Basic-Leucine Zipper Transcription Factors; Binding Sites; DNA-Binding Proteins; Helix-Loop-Helix Motifs; Humans; Ornithine Decarboxylase; *Promoter Regions, Genetic; Protein Precursors; Proto-Oncogene Proteins c-myc; Rats; Thymosin; *Transcription Factors

Disciplines

Genetics and Genomics

Abstract

Previously, we have shown that c-Myc/Max heterodimers, bind cooperatively to the two adjacent, canonical E-boxes (CACGTG) located in the rat ornithine decarboxylase (ODC) gene. In order to study this in more detail, we changed the length of the linker that separates the two E-boxes, as well as their flanking sequences. We found that high affinity, cooperative binding requires a minimal linker length of 1-4 bp and that the binding affinity is influenced by E-box flanking sequences. Binding to the c-Myc responsive element of prothymosin alpha, containing both a canonical and a noncanonical E-box (CAAGTG) was also studied. As shown by DNAseI footprinting analysis, only the canonical E-box is bound by c-Myc/Max and c-Max/Max dimers. Replacing the noncanonical site with a canonical E-box only partially restored high affinity, cooperative binding. By making hybrid fragments between ODC and prothymosin alpha, we found that nucleotides in the linker between the E-boxes influence the affinity of c-Myc/Max heterodimers. Taken together, our results show that E-box sequences and sequences in the linker separating both E-boxes influence cooperative, high affinity binding by c-Myc/Max dimers.

Rights and Permissions

Citation: Biochim Biophys Acta. 1998 Apr 29;1397(2):189-201. Link to article on publisher's site

Comments

At the time of publication, Albertha J. Marian Walhout was not yet affiliated with the University of Massachusetts Medical School.

Related Resources

Link to Article in PubMed

PubMed ID

9565685