Vps1's Implication on Late Endosome-to-Vacuole Traffic

Date of Graduation

Spring 2012

Degree

Master of Science in Biology

Department

Biology

Committee Chair

Kyoungtae Kim

Abstract

Previous studies have shown Vps1 to be necessary for both sorting of soluble vacuolar proteins from the Golgi and retention of Golgi membrane proteins. I have recently found that Vps1 is implicated in membrane trafficking from the plasma membrane through the endosomal system to the vacuole. Loss of Vps1 resulted in accumulation of FM4-64 puncta that colocalize with a late endosomal marker (GFP-Pep12), indicating a slower late endosome-to-vacuole traffic. In addition, Vps1 was found to genetically interact with Vps36 and Ypt7, which are involved in the late endosome-to-vacuole traffic. Protein's functional role is generally correlated with its localization, so I investigated the subcellular localization of Vps1-GFP in relation to endocytic sites and endosomal compartments. In a FM4-64 pulse-chase experiment, I found that the extent of colocalization of FM4-64 with Vps1-GFP drastically increased after 20 min chase, indicating Vps1-carrying vesicles are among the population of late endosomal compartments. Consistently, I observed that Vps1-GFP coincides with PI3P (endosomal marker), but not with the plasma membrane endocytic markers such as Abp1 and Ede1, suggesting that Vps1 is a component of endosomal compartments. Taken together, I postulate that Vps1 is required for an efficient traffic toward the vacuole from late endosomal compartments.

Keywords

Vps1, endosome, vacuole, trafficking, FM4-64

Subject Categories

Biology

Copyright

© Jacob Robert Hayden

Citation-only

Campus Only

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