EAPSI: Determining the Atomic Structure of Proteins that Form Brain Connections

Gray Kevin T, Pullman WA

Investigators

Abstract

The brain communicates and forms memories through a specialized group of cells called neurons. These cells form connections through extensions called neurites. Neurites are formed when neurons alter their protein skeleton to reach for other cells. Disruptions to the cellular skeleton can harm memory formation. Tropomodulins (Tmods) are a family of proteins that contribute to the formation of the cellular skeleton in neurons. During seizures, strokes, and methamphetamine exposure and also in Down syndrome and epilepsy, the amounts of Tmods in the brain have been shown to be vastly altered. Understanding the role of Tmods in brain development will elucidate these conditions and may lead to treatments. Previous studies have shown that variation in Tmods' roles in neurite formation correlates with structural differences. The goal of this project is to determine the atomic structure (determinant in protein function) of Tmod2 for comparison with the known structure of Tmod1. This project will be conducted in collaboration with Dr. Fadel Samatey, an expert in protein structure at the Okinawa Institute of Science and Technology in Japan. A solved structure for Tmod2 will uncover details about Tmods' finely tuned role in brain development and disruption in disease states. Crystallization and X-ray Diffraction are techniques that will be used to determine protein structure. This project aims to screen for and optimize crystallization conditions for the leucine rich repeat (LRR) domain of Tmod2 and then determine its structure by X-ray Diffraction. This domain is important for localization of Tmods in muscle cells, thymosin binding and Tmod's actin nucleation ability. Comparison of Tmod structures will lead to residues for mutagenesis that will connect the structure of these proteins to their roles in neurite formation. This NSF EAPSI award is funded in collaboration with the Japan Society for the Promotion of Science.