Structure of Epac2 in complex with a cyclic AMP analogue and RAP1B

Holger Rehmann, Ernesto Arias-Palomo, Michael A. Hadders, Frank Schwede, Oscar Llorca, Johannes L. Bos

Research output: Contribution to journalArticlepeer-review

125 Scopus citations


Epac proteins are activated by binding of the second messenger cAMP and then act as guanine nucleotide exchange factors for Rap proteins. The Epac proteins are involved in the regulation of cell adhesion and insulin secretion. Here we have determined the structure of Epac2 in complex with a cAMP analogue (Sp-cAMPS) and RAP1B by X-ray crystallography and single particle electron microscopy. The structure represents the cAMP activated state of the Epac2 protein with the RAP1B protein trapped in the course of the exchange reaction. Comparison with the inactive conformation reveals that cAMP binding causes conformational changes that allow the cyclic nucleotide binding domain to swing from a position blocking the Rap binding site towards a docking site at the Ras exchange motif domain.

Original languageEnglish (US)
Pages (from-to)124-127
Number of pages4
Issue number7209
StatePublished - Sep 4 2008
Externally publishedYes

ASJC Scopus subject areas

  • General


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