Date of Award

6-2012

Document Type

Open Access

Degree Name

Bachelor of Science

Department

Biology

First Advisor

Barbara Danowski

Language

English

Keywords

microtubules, depolymerization, enzyme, modification, stability

Abstract

Microtubules, or cytoskeletal polymers composed of the protein tubulin, form long hollow tubes in the cell and are responsible for many critical roles. Previous research has shown that depletion of ATP causes microtubules to become stable, i.e. resistant to depolymerization. It has also been shown that enhanced stability of microtubules correlates with increased tubulin acetylation, a common microtubule posttranslation modification. ATP-depletion is a severe metabolic stressor, and as such, we expect that this treatment would activate AMP kinase, an enzyme deemed the “master regulator” of metabolism. When activated by a variety of stressors, this enzyme can initiate a program of limited ‘self-destruction’ called autophagy, which requires microtubules for the transport of autophagosomes. By using western blot analysis, I ascertained that tubulin acetylation increases upon ATP-depletion and that AMP kinase is activated upon ATP depletion in mouse embryo fibroblasts (C3H 10T1/2). By western blot analysis and immunofluorescence microscopy I also confirmed that ATP-depletion causes the acetylation of microtubules and that these acetylated microtubules are resistant to depolymerization by nocodazole. These results suggest a link between tubulin acetylation and the control of ATP levels in the cells.

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