Research Symposium

BIO

My name is Gregory Regala and I am a second-year honors student studying Biochemistry on a pre-proffessional track. I am from Orlando, FL and really enjoy learning about the mechanisms that drive the biological functions of life. Outside of class and research I am actively involved in the Asian American Student Union, Lambda Phi Epsilon International Fraternity Inc., and previously served as an ambassador for APIA Vote.

Investigating the Role of Csm1 in Ulp2 Localization and its Effects on Sister Chromatid Separation

Abstract

In the model organism Saccharomyces cerevisiae, or budding yeast, the protein Ulp2 plays a crucial role in chromosome cohesion. Ulp2 is a peptidase that deconjugates Smt3/SUMO-1 peptides from proteins, contributing to chromosome cohesion at centromeric regions, recovery from checkpoint arrest due to DNA damage or replication defects, and RNA splicing. It is also a potential Cdc28p substrate, with its human homolog, PML, implicated in promyelocytic leukemia (Engel, 2024).

Ulp2 ensures proper sister chromatid separation by removing SUMO chains at the right time. Research suggests that Csm1, a key nucleolar protein, may regulate Ulp2 localization. While Ulp2 is found in the nucleolus during most of the cell cycle, it relocates to the kinetochore during anaphase. To investigate the effect of Csm1 deletion (Csm1Δ), Ulp2 localization can be tracked using the fluorescent protein tag NG, while the kinetochore protein Nuf2 is tagged with MCH. Further analysis through a NOC arrest allows for synchronized cell cycle evaluation in Csm1Δ mutants.

If Csm1 influences Ulp2 localization, Csm1Δ cells may exhibit premature sister chromatid separation. This hypothesis can be tested using fluorescent tagging of Cen4 with GFP and Tub1 with MCH. In Csm1Δ mutants, Ulp2 is expected to disperse throughout the cytosol instead of concentrating at kinetochores.

This research enhances our understanding of biochemical pathways linked to human diseases, such as cancer and chromosome nondisjunction, by shedding light on Ulp2’s role in chromosomal stability.

Keywords: Biology, Proteins, Biomedical, Cancer