Date: 11 January 2024 (Thursday)
Time: 5:00 pm – 6:00 pm
Venue: Cheung Kung Hai Lecture Theatre 1, G/F, William M.W. Mong Block, 21 Sassoon Road

5:00 p.m.

Presenter: Haoran QI (MPhil candidate)
Primary Supervisor: Dr. Mu HE
Presentation Title: Single Molecule analysis of KIF27 shows its slow processive movement with long binding duration along ciliary microtubules
Abstract: Kinesin motor proteins play important roles in intracellular transport, ciliary function and microtubule dynamics regulations. KIF27 is a kinesin motor protein from Kinesin-4 family and homologues to the mammalian KIF7. KIF27 knock-out mice exhibit hydrocephalus and nasal mucus obstruction, indicating cellular defects associated with motile cilia. To gain insight into its roles in regulating motile biogenesis and function, we set out to characterize the modes of actions for KIF27 using recombinant proteins and TIRF microscopy.

By purifying KIF27 motor dimer proteins, and motile cilia specific tubulin isotype, TUBB4B-A1A, we performed microtubule motility assay and microtubule gliding assay using Total Internal Reflection Microscopy (TIRF-M) to investigate the motility of KIF27 single molecules on in vitro polymerized microtubules. Meanwhile, we also purify the KIF27 E160A and R206K mutants which supposed to let the motor lose ATP dependent motility and allow us to generate a mice model to observe whether there’re changes in phenotypes. The results from in vitro assays suggest that KIF27 is an active and motile protein with slow motility and long binding duration. This result reveals KIF27’s interaction with microtubules and highlights KIF27’s distinct features such as different velocity and binding duration compared to KIF7 and KIF4 from Kinesin-4 family. It suggests that KIF27 may play different roles within motile cilia such as potentially engaged in Intraflagellar Transport (IFT) when there’s cargo loading or potential interactions with other kinase proteins. These results also contribute to a deeper understanding of the diverse functions of KIF27 in cellular processes.

5:30 p.m.

Presenter: Jia Yan Tan (MPhil candidate)
Primary Supervisor: Dr. Eric WONG
Presentation Title: Role of plexin A3 in hepatocellular crcinoma progression
Abstract: Plexin/semaphorins are important regulators for cell migration and recent studies have implicated their involvement of cancer growth and metastasis. The study aims to investigate the potential involvement of PLXNA3 during hepatocellular carcinoma (HCC) progression. We have identified PLXNA3 expression to be associated with poorer clinical outcomes, suggesting its potential as a prognostic marker in HCC. Moreover, functional assays also demonstrated a significant association between PLXNA3 expression and enhanced migratory, invasive, cell proliferative and tumor-initiating abilities in HCC cells. Further investigation into the regulatory mechanisms of PLXNA3 expression in HCC revealed that hypoxia-inducible factor 1α (HIF1α) is involved in the transcriptional regulation of PLXNA3, suggesting a potential link of PLXNA3 expression in the hypoxic tumor microenvironment. In summary, current evidences demonstrated the role of PLXNA3 expression in the development of HCC. Future work will focus elucidating the downstream mechanism of PLXNA3 in HCC progression.

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