Date of Award


Document Type


Degree Name

Master of Science (MS)


College of Science and Mathematics



Thesis Sponsor/Dissertation Chair/Project Chair

Carlos A. Molina

Committee Member

Lee H. Lee

Committee Member

John J. Gaynor


Melanoma--Research, Genetic repressors


Inducible cAMP early repressor (ICER) is an endogenous repressor of cAMPresponsive element (CRE) with antiproliferative properties that acts as a potential suppresser for tumors especially melanoma. ICER activity and cellular localization are orchestrated by the performance of the post-translational modifications (PTMs). Ubiquitination and sumoylation are two of the most important types of PTMs that control diverse groups of biological processes for ICER protein. The goal of this project is to study how post-translational modifications alter the function of the transcriptional repressor Inducible cAMP Early Repressor (ICER) in melanoma cells. Since ICER ubiquitination and sumoylation processes take place on the interaction between the ubiquitin and the lysine residues of ICER amino acid sequence, my interest was focused on the downstream targets of each ICER mutants. Through the application of site-directed mutation to the multiple ubiquitination positions of the amino acid Lysine (K) and replacing them by Arginine (R). Then, ICER’s wild type and mutant DNA were transfected into human mammalian model melanoma cells; SK-MEL-24 and subjected to immunocytochemistry, Western Blot and half-life analyses to further understand the modification and regulatory nature of ubiquitination and sumoylation pathways. The results presented an insight on the cellular distribution of ICER mutants’ expression as well as hinted at the importance of ubiquitination and sumoylation in terms of ICER stability.

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