Downstream Regulatory Element Antagonist Modulator (DREAM), also known as calsenilin or K+ channel interacting protein 3 (KChIP-3) belongs to the group of neuronal calcium sensor proteins that are found predominantly in neuronal cells where they regulate diverse aspects of neuronal function ranging from neurotransmitter release to neuronal growth and apoptosis. DREAM is a highly multifunctional protein that interacts with presenilin-1 and presenilin-2, acts as a transcriptional repressor for a number of genes including c-fos gene and prodynorphin gene in Ca2+ dependent manner, and interacts and modulates the activity of A-type of K+ channels. Understanding how calcium-induced conformational changes within EF-hand motifs of DREAM control the protein association to DNA target sequence and modulate the K+ channel activity requires determination of kinetics and energetics of conformational changes that are associated with the transition between apo- and calcium-loaded forms of DREAM as well characterization the impact of the Ca2+ binding on the DREAM equilibrium dynamics. The emphasis of this project is to probe conformational heterogeneity and dynamic motion of DREAM in apo- and Ca2+ bound state using time-resolved fluorescence and anisotropy techniques and to construct time-resolved thermodynamic profiles in terms of volume and enthalpy changes for Ca2+/Mg2+ binding to DREAM using sensitive photothermal beam deflection method in combination with caged calcium compounds that enable rapid increase in Ca2+ concentration. This study will thus determine the role of the individual EF-hands in the Ca2+ signal transductions, the mechanism of signal transduction between the C- and N-terminal domains as well as the role of N- and C-terminal helices in interaction between DREAM and effector proteins.This project will provide multi-disciplinary educational opportunities to graduate and undergraduate students, who will receive broad training in modern experimental biophysics and biochemical methods including protein chemistry. Students' work will be disseminated at national and regional meetings and students will co-author publications. The emphases will be on giving students hands on exposure to advanced topics in an effort to stimulate their interest in chemistry and biophysics. The effort to recruit and train female and minority students will continue with the goal to increase participation and retention of students that are underrepresented in sciences.
