UROP Proceedings 2021-22

School of Science Division of Life Science 15 Molecular Mechanisms Regulating Biogenesis of Peroxisomes Supervisor: GUO Yusong / LIFS Student: LI Chun Wa / BCB Course: UROP3100, Summer Peroxisomes are vital organelles for most eukaryotes, while they undergo growth and division under homeostatic conditions, they can be generated de novo when depleted. Although the biogenesis of organelle occurs in the ER of yeasts and plants, peroxisomes in mammalian cells have an interesting dual origin from the ER and the mitochondria, in which peroxins Pex3 and Pex16 are the key players in the formation process. To unravel the underlying mechanisms regulating this event, we aim to utilize retention using selective hooks (RUSH) assay to study the trafficking machineries of these peroxins from these 2 donor organelles by synchronizing the vesicle release of these proteins. In UROP 3100, immunofluorescence was performed to determine the localization of Str-Ii_Pex16-SBPEGFP and Str-HA-MAO_VSVG-SBP-EGFP, the ER and mitochondria hook for Pex16 and Pex3, respectively. Our study shows that while VSVG-SBP-EGFP successfully retained in the mitochondria, Str-Ii failed to lock Pex16-SBP-EGFP in ER but instead allowed it to be transported to the ER. Molecular Mechanisms Regulating Biogenesis of Peroxisomes Supervisor: GUO Yusong / LIFS Student: YAU Yin Lam / SSCI Course: UROP1100, Summer In the eukaryotic secretory system, endoplasmic reticulum (ER) and Golgi apparatus play important roles. During the secretion process, coat protein complex II (COPII) captures cargo proteins at ER and form vesicles in a bid to transfer the proteins to Golgi apparatus. Previous studies have shown that PRRC1, a cytosolic factor, may be involved in COPII disassembly, and knockdown of PRRC1 can affect the efficiency of ER transport as well as membrane associations of COPII coats. The C-terminus(263-445) of PRRC1 contains a nucleotide phosphatase (NTPase) domain. To investigate whether the NTPase domain of PRRC1 is critical for its function, His-PRRC1(263-445)-HA has to be generated for carrying on further experiments. CRISPR Cas9 Based Therapeutic Strategy for Alzheimer's Disease Supervisor: IP Nancy Y / LIFS Co-supervisor: FU Kit Yu / LIFS Student: WONG Lok Yin / IRE Course: UROP1100, Summer Familial Alzheimer’s disease(FAD), which accounts for about 5% of all Alzheimer’s disease cases, is caused by one of more than 330 gain-of-function mutations in amyloid precursor protein (APP), presenilin 1 (PSEN1), and presenilin 2 (PSEN2) genes. Previous studies have shown that allele-specific disruption of mutated APP or PSEN1 by targeting mutations directly with CRISPR-Cas9 can effectively alleviate amyloid-related pathologies. Although this gives a promising cure to FAD, more than 330 CRISPR–Cas9 constructs are required for all identified FAD-related mutations, which is not feasible. This project aims to develop a generalized treatment for all FAD patients by targeting non-disease-causing single-nucleotide polymorphism(SNP). Here, this report systematically validated performance of sgRNAs for targeting candidate SNPs.