ABSTRACT Phagosome clearance is a major function of the retinal pigment epithelium (RPE), one that is essential for the health of the retina, and therefore our sense of vision. The clearance of phagosomes in the RPE is dependent on molecular motors that orchestrate their transport towards lysosomal compartments for degradation. This delivery involves the microtubule plus-end motor, kinesin-1. However, despite their net movement in the anterograde direction, phagosomes exhibit bidirectional motility on microtubules in the RPE. This indicates the actions of the retrograde motor, dynein, which moves various cargos in eukaryotic cells towards the minus-end of microtubules. The role of dynein in the trafficking of phagosomes in the RPE is not understood. My current research will focus on the contributions of dynein to the motility of phagosomes that promotes their efficient clearance by the RPE. In aim 1, I will utilize state-of-the-art live-cell imaging on human RPE cells to test the role of dynein in mediating transient interactions between phagosomes and degradative endolysosomal compartments. In aim 2, I will perform in-depth molecular studies into the mechanisms that regulate dynein- based transport in the RPE by investigating molecular intermediaries, called adaptor proteins, which link the motor to its cargo. This will provide answers to how the dynein microtubule motor controls cargo specificity by a combinatorial assembly of adaptor proteins. It will also shed light on how adaptor proteins participate in regulating the coordination between opposing microtubule motors that brings about precise intracellular transport. In applying for this award, my goal is to develop an independent research program at the interface of RPE cell biology and molecular motor proteins. My development plan consists of obtaining expertise in advanced live-cell imaging on human RPE (with Dr. David Williams, UCLA) and in-depth molecular training on the dynein motor (with Dr. Samara Reck-Peterson, UCSD). In addition to my research training, I will attend various conferences in vision science and general cell biology, as well as participate in UCLA-sponsored programs that facilitate my transition to an independent principal investigator. Finally, my co-mentors will provide me with guidance on managing a laboratory, training research staff, and preparation of grant applications for several types of funding mechanisms. Collectively, this development plan will prepare me well to obtain and excel in an independent position at a research institution.