Date of Graduation

Spring 2012


Master of Science in Cell and Molecular Biology


Biomedical Sciences

Committee Chair

Joshua Smith


Thd14, sirtuin, stress response, DNA damage, Tetrahymena thermophila

Subject Categories

Medical Molecular Biology


Thd14 is a histone deacetylase (HDAC) present in the ciliate Tetrahymena thermophila and is a member of the sirtuin family of HDACs. Sirtuins are thought to affect many cellular processes including those related to: cancer, diabetes, life span, and Parkinson's disease. Previous research has shown that Thd14 may be involved in degradation of the macronucleus during conjugation. Thd14 has also been shown to associate with nucleoli in the macronucleus in vegetatively growing cells and to form a large nucleolar associated aggregate in response to starvation. The goal of this research was to characterize the role of Thd14 following DNA damage. This research has determined that expression of THD14 increases in response to DNA damage by MMS, UV or H2O2. Localization studies using GFP-Thd14 revealed that Thd14 forms a large aggregate in the macronucleus following treatment with MMS, UV or H2O2. Overexpression of Thd14 was found to decrease survivability of cells treated with H2O2; while knockdown of Thd14 by shRNA increased survivability following MMS treatment. Through co-immunoprecipitation coupled with mass spectrometry, Thd14 was found to interact with a Tetrahymena homologue of Hsp70a. These findings and those made previously indicate that Thd14 is a stress responsive sirtuin, with changing localization and expression in response to genotoxic or metabolic stress.


© Kyle Aaron Cottrell

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