Date of Graduation

Summer 2010


Master of Science in Biology



Committee Chair

Kyoungtae Kim


eisosome, endocytosis, recycling, slm1, slm2, vesicles

Subject Categories



Endocytosis is the process by which cells recycle the plasma membrane and internalize extracellular components. Slm1 has been identified as a component of eisosome, a static site for endocytosis. Previous studies have shown colocalization between Sur7, an eisosome component with Slm1 and Pil1. Here, I found that Slm1 and Pil1 partially colocalize with each other and inactivation of Slm proteins disrupt the localization of Pil1at nonpermissive temperature. Slm proteins are required for actin cytoskeleton organization and hence endocytosis. Analysis of inactivated Slm proteins reveals that FM4-64 dye trafficking is inhibited at both permissive and non-permissive temperatures. Due to the fact that the severity in actin disruption is correlated with the severity of endocytic defects, I found that the inactivation of SLM genes led to defects in the actin cytoskeleton organization at an optimal temperature. As intact actin cables are important for endosomal motility, I found that endosome motility at optimal temperature was severely restrained in slmts cells. Lack of either Slm1/2 did not show any defect on the receptor-mediated endocytic (RME) pathway. A FM4-64 recycling assay showed that a slmts (slm1-3tsslm2Δ) cell exhibited a recycle defect. I also found that this recycling defect observed in slmts is not dependent on the actin organization. Together, these data indicate that Slm1/2 are important players in the organization of the eisosome and are required for the efficient endocytic trafficking via proper actin cytoskeleton organization, and in recycling through actin independent mechanism. KEYWORDS: eisosome, endocytosis, recycling, slm1, slm2, and vesicles.


© Chitra P. Kamble

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