Secondary structure creates mismatched base pairs required for high-affinity binding of cAMP response element-binding protein to the human enkephalin enhancer.

Published

Journal Article

Transactivation studies of the enkephalin enhancer indicate that two cAMP response elements (CRE-1 and CRE-2) are needed to mediate the transcriptional response to cAMP and to the CRE-binding protein (CREB) transcription factor. CRE-1 and CRE-2 are contained within a nearly palindromic region that can form stable hairpin structures in vitro. CREB binds only weakly to the native duplex enhancer and only within CRE-2. In contrast, CREB binds with high affinity to the hairpin in which CRE-1 and CRE-2 come together to form a CREB site with two G.T base pairs. NMR and binding studies show that high-affinity binding to the G.T hairpin requires one of the mismatched G.T pairs. Insertion of that G.T pair into the duplex confers high-affinity binding. Parallel studies with the somatostatin CRE show that the T in one G.T pair is crucial for high-affinity binding. The existence within a short enhancer of alternative sites for a single factor suggests a mechanism for regulation of transcription by DNA structure.

Full Text

Duke Authors

Cited Authors

  • Spiro, C; Richards, JP; Chandrasekaran, S; Brennan, RG; McMurray, CT

Published Date

  • May 15, 1993

Published In

Volume / Issue

  • 90 / 10

Start / End Page

  • 4606 - 4610

PubMed ID

  • 8506306

Pubmed Central ID

  • 8506306

International Standard Serial Number (ISSN)

  • 0027-8424

Digital Object Identifier (DOI)

  • 10.1073/pnas.90.10.4606

Language

  • eng

Conference Location

  • United States