Intracellular Targeting of CaM Kinase II Oligomers

Virginia Commonwealth University, Richmond VA

Investigators

Abstract

A long-term objective of the research in this laboratory is to understand how extracellular cues influence the growth and pathfinding properties of developing neurons. In this project, the role of the enzyme CaM kinase II (CaMK-II) will be characterized during neurogenesis. CaMK-II activity is increased by transient elevations of intracellular calcium. Calcium levels transiently rise at different times and locations in developing neurons. Activated CaMK-II then modifies other proteins by a process called phosphorylation. Which of the four CaMK-II genes is expressed determines the proteins that are phosphorylated. In early embryonic neurons, one of these CaMK-II genes (delta) encodes the majority of the CaMK-II proteins. Later during development, CaMK-IIs are also encoded by the beta CaMK-II gene to supplement delta CaMK-IIs. In this project, the capability of beta and delta CaMK-IIs to interact will be investigated. This is important because the interaction of CaMK-IIs can influence their location and their choice of protein targets. Some of these targets will be identified. The function of beta and delta CaMK-IIs will then be examined during neurogenesis. Functional studies will be conducted in a mouse embryonic cell line (P19) because P19 cells can be differentiated into neurons in vitro and naturally express beta and delta CaMK-IIs. Levels of CaMK-IIs can be increased or decreased in P19 cells and the effect on neurogenesis can then be analyzed. This research will help to better understand the level of protein diversity that can be achieved through alternative gene expression and protein interaction. The research will also contribute to an understanding of the principles of protein assembly and targeting. Finally, this research will provide new insight into the mechanisms by which neurons are formed.