Date of Graduation

Fall 2014

Degree

Master of Science in Biology

Department

Biology

Committee Chair

Kyoungtae Kim

Abstract

Vacuolar Protein Sorting 1 (Vps1), the yeast homolog to human dynamin, is a GTPase that acts as a pivotal component in membrane trafficking. In light of observations that VPS1 displayed positive genetic interactions with four genes implicated in the recycling traffic (YPT6, GYP1, RCY1, and RIC1) and with seven ESCRT (Endosomal Sorting Complex Required for Transport) components in the degradation traffic (VPS22, 23, 24, 25, 28, 36, and 37), I investigated the possibility of the physical interactions of Vps1 with the eleven regulators, using a yeast two-hybrid system, and identified novel Vps1 binding partners, including Ypt6, Vps22, Vps24, and Vps36. The GTPase and middle domain of Vps1 appeared to have higher affinities to Ypt6 than the full-length Vps1, whereas the full length of Vps1 had a higher binding affinity to Vps22 than shorter fragments of Vps1. I also provide evidence from an overexpression assay that Vps1 functions downstream of Ypt6. According to the qRT-PCR analysis, the mRNA expression levels of traffic factors were not affected in the absence of VPS1. In addition, the yeast two-hybrid genome-wide screening results revealed Ste24 as a novel binding partner of Vps1. Taken together, my results support an important role of Vps1 in major intracellular trafficking processes, providing novel insight into the activity of Vps1.

Keywords

Vps1, Ypt6, ESCRT, recycling traffic, degradation traffic

Subject Categories

Biology

Copyright

© Hyoeun Ahn McDermott

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