UROP Proceedings 2020-21

School of Science Division of Life Science 39 Calcareous Dinoflagellates Supervisor: WONG Joseph Tin Yum / LIFS Student: MONG Sze Hang / BIOT Course: UROP1000, Summer Being one of the calcareous dinoflagellates, Thoracosphaera heimii works as a major sink of atmospheric carbon dioxide in the world’s oceans (Elbrachter et al., 2008). Moreover, after being found in fossil records from the Cretaceous onwards, T. heimii. can be one of the Paleocene-graphic proxy archives for the reconstruction of the ancient oceanic environment and a better understanding of climate changes (Karwath et al., 2000). Yet, little is known for this species, and thus, it is worth researching the importance behind T. heimii.. With this notion, this report would like to give a fundamental understanding regarding the life cycle of T. heimii. as well as various features of it, including distribution of photosynthetic pigments and crystallization on the cell wall, through observation by light microscope and polarizing light microscope. The Intein Approach for Efficient Production and Purification of Recombinant Proteins in Escherichia Coli Supervisor: WONG Wan Keung / LIFS Student: YUK Tin Cheung / BTGBM Course: UROP1100, Fall Basic Fibroblast Growth Factors is a protein that was found to have versatile applications in the medical stream, including the wound and bone healing, the treatment for myocardial infection. Studies even revealed its potential in stimulating the angiogenesis and neuron extension. Previously, bEGF were extracted from natural sources including placenta, carpus luteum, yet the shortcomings associated with natural extraction were the small quantities and low yield of bEGF obtained. Therefore, scientists have turned to genetically modifying bacteria like E.coli for generating higher quantity of desirable bEGF products. Thanks to the previous researches, a comprehensive method has been developed to isolated the desired bEFG proteins from the cluster of fusion proteins, protein aggregates and other variants from the bacterial expression. In this report, methodologies and results will be presented to cover my experience adopting the technique for extracting the bEGF proteins from the E.Coli cells. G Protein-Coupled Receptors in Cell Signaling Supervisor: WONG Yung Hou / LIFS Student: LIU Zhiyin / BCB Course: UROP1100, Summer Melatonin receptors in mammals termed MT1 and MT2 are members in G protein-coupled receptors(GPCRs) which regulate circadian rhythm and they can form homodimers and heterodimers during signaling. Tango is an assay applied to detect GPCR activation for agonist ligands by the recruitment of β-arrestin which is G protein-indepedent and release of transcription factor (tTA) due to site-specific cleavage. It transfers the instant combination to a stable and visible luciferase gene expression and amplifies the small input signals, which provides us a novel way to detect dimerization of GPCRs. In this study, we propose that bioluminescence can be detected due to dimerization of melatonin receptors by replacing the β-arrestin with MT1/MT2 and modified Tango construct with MT1/MT2 and TEV protease are built. Similar construct modification for other GPCRs can be applied to further research on determination of dimerization.