UROP Proceedings 2021-22

School of Science Division of Life Science 23 Modeling Peroxisomal Disorders with C. Elegans Supervisor: MAK Ho Yi / LIFS Student: FUNG Ching Nam / SSCI Course: UROP1000, Summer Peroxisome plays an important role in human metabolism, including b-oxidation of very long chain fatty acid and synthesis of plasmalogen (Wang & Subramani, 2017). Mutations in PEX genes, which encode peroxins, could result in peroxisome biogenesis disorders such as Zellweger spectrum disorder (ZSD) (Wang & Subramani, 2017). It was previously reported that peroxisomal beta-oxidation defects in C. elegans caused abnormal lipid droplet expansion (Zhang et al, 2010). Results here shows the effect of diet intervention on lipid droplets size and peroxisomal matrix protein transport in prx-10 mutated C. elegans. Additional plasmids were constructed for further interrogation of PRX-10 function in C. elegans in the future. miRNA Processing Supervisor: NGUYEN Tuan Anh / LIFS Student: JUNG Kwangsek / BIOT Course: UROP1100, Summer With the growing interest in microRNA's role in cellular functions, its biogenesis and maturation are being studied more intensely. This project looks into the effects of mutations in the sequence of the micro-RNA 142 and how it influences the maturation step from primary micro-RNA to pre-micro-RNA. 3 separate mutations, previously reported in human cancer genome sequencing have been opted for analysis. MiRNAs were synthesized in vitro and were used for cleavage assay with Drosha3-DGCR8 microprocessor complex. This report has demonstrated how mutations in the different region affect the cleavage efficiency and the position of the cleavage. Targeting Mitotic Regulators in Cancer Cells for Potential Treatment Supervisor: POON Randy Yat Choi / LIFS Student: CHING Chi Yin / BCB Course: UROP2100, Fall UROP3100, Spring It has been found by our laboratory that during mitosis, Programmed death-ligand 1 (PD-L1) expresses a second band (other than the normal band found in interphase) in Western blots. We hypothesize that PDL1 could be post-translationally modified during mitosis. We intend to investigate the identity of the second band by transfecting various modified constructs of PD-L1 before inducing a mitotic block. It is proven that the transfected PD-L1 shows a similar pattern as the endogenous one which is mentioned in the previous report. For these studies, we focus on cloning and transfecting truncated PD-L1 to study the position of the modification. The studies indicate that the 133-290 truncated and 1-132 truncated PD-L1 only show a single band pattern and with no mitotic shift in the western blot when using HeLa as cell models.