Clathrin-coated vesicles (CCVs) modulate receptor-mediated endocytosis (RME) and neurotransmission, two critical events that regulate neuronal growth and nervous system function. However, how the CCV cycle is adapted to neuronal function remains obscure. The proposed studies will explore and disrupt the functions of clathrin light chains (LCs), key regulators of clathrin dynamics, to learn how CCV trafficking mediates neuronal differentiation and function. Interestingly, two divergent LCs (LCa and LCb) are disproportionately expressed in neurons relative to other cell types, possibly to facilitate neurotransmission in addition to RME. Additionally, neurons are largely composed of alternatively spliced LCs. To distinguish the functions of LCa, LCb and their neuronal counterparts, a yeast two-hybrid system will screen proteins that specifically bind these species. Analysis of candidate proteins will elucidate their respective roles in modulating clathrin dynamics in the neuronal and non-neuronal cell. Additionally, LCa and LCb expression will be disrupted in zebrafish and mouse to distinguish the in vivo functions of the respective LCs in neuronal development and nervous system function. The null genotypes will be analyzed for membrane trafficking, synaptic and cognitive deficiencies. Ultimately these complementary approaches will reveal how LC-regulated CCV trafficking specifies tissue and neuronal function. ? ? The candidate Dr. Newmyer has extensive experience in studying constitutive CCV-mediated trafficking in cultured non-neuronal cells. The proposed research will expand her membrane trafficking expertise to studying regulated CCV trafficking within the neuron and within zebrafish and mouse. Dr. Newmyer has established collaborations within UCSF to analyze LC-regulated clathrin function within mice and zebrafish. The proposed studies will identify proteins and generate cell lines to establish a strong research program that identifies the molecular and cellular mechanisms that modulate tissue-specific CCV trafficking. Ultimately, this project will enable the candidate to develop into a neuroscientist and pursue an academic tenure track faculty position.