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Melissa Cabral defends her thesis for her MS in Molecular Biology. Watch the presentation on Zoom.

Abstract

Cell division is a highly regulated, multi-complex system often requiring an asset of proteins working in conjunction with one another. This much needed unity is what ensures proper examination of the cell before entering a new phase of the cell cycle. However, cells that infringe multiple phases of the cell cycle (often in the G2 phase), are known to be malicious cancer cells, growing at an untamable rate. The transcriptional repressor, Inducible cAMP Early Repressor, ICER, has not been found to be expressed in many cancer cell lines (Mémin et al., 2011). This abnormal expression for a transcription factor like ICER is questionable since it’s related in regulating growth associated genes that are common for many cancerous cells to hijack. Along with ICER being found in healthy cell tissues, it has also been present in the β‐adrenoceptor pathway. β‐adrenoceptor receptor regulation is related to the sympathetic pathway that would include the cardiovascular system (Tomita et al., 2003). The importance of ICER is related to a cell’s vitality and healthy function.

In this report, we used two commercial based, enhanced green fluorescent protein, EGFP constructs to study the subcellular localization of ICER in human melanoma cells, SK-MEL-24. The constructs were designed to have EGFP either on the N-terminus or C-terminus of ICER-II. The purpose of this design is to witness if the absence of a termini in ICER-IIγ would affect its native localization of the nucleus. The data demonstrate that the EGFP position on ICER did not affect its nuclear localization. Interestingly, the construct of ICER-IIγ with EGFP on its C-terminus was also observed in the centrosome of mitotic cells. Taken together, our results suggest that ICER-IIγ’s N-terminus may be important in a signaling pathway that is related to the cell cycle.