EPAC2 MD Simulation

In eukaryotes, the exchange protein directly activated by cAMP (EPAC) is a crucial cAMP receptor that regulates important signaling cascades. It has been demonstrated that auto-inhibition is an approach used by epac proteins to regulate the balance between the active and inactive states. The N-terminus of the CBD provides an ionic interface that masks the Rap recognition site's perimeter in the absence of cAMP. This interface is weakened by cAMP binding at the distal Phosphate Binding Cassette (PBC). Comprehensive unexpected dynamic features, explaining previously unidentified facets of EPAC activation and autoinhibition. The simulations demonstrate, in particular, that cAMP binding significantly perturbs the dynamics in the distal catalytic region, which aids in the identification of the Rap1b substrate.

Furthermore, examination of the activation intermediates suggests that EPAC allostery may be mediated by a hybrid mechanism that combines aspects of conformational selection and induced fit.

Cyclic Adenosine Monophosphate (cAMP) mediates the guanine nucleotide exchange factor EPAC (Exchange Protein Activated by Camp) to a tiny protein Rap. Since cAMP signaling regulates a number of regulatory pathways and keeps EPAC levels stable, an overexpression of this signaling cascade can lead to neurological and cardiovascular illnesses as well as malfunction. EPAC proteins are found in several subcellular locations and have a multidomain structure with several isoforms. Furthermore, it can exist in various states with (open) or without (closed) cAMP. In this work, we focused on EPAC2, hoping to use dynamics analysis to find structural insights.