Date: Friday, 10 December 2021

Venue: Seminar Room 2&3, G/F, Laboratory Block, 21 Sassoon Road, Pokfulam, Hong Kong

Time: 5:00 p.m. - 6:00 p.m.

5:00 p.m.

Speaker: Mr. Chun Hin LEE (PhD candidate)
Primary Supervisor: Dr. Joshua Wing Kei HO
Presentation Title: Bioinformatics methods for mass-spectrometry-based multi-omic data integration
Abstract: Liquid chromatography-mass spectrometry (LC-MS) is a commonly used method for untargeted metabolomic study. Nonetheless, its widespread adoption is hindered by computational and statistical challenges in compound identification, filtering, data normalisation, and statistical analysis. Our overseas collaborators have recently developed a LC-MS based experimental protocol, called Multi-ABLE, which enables simultaneous profiling of metabolomic, lipidomic and proteomic data using a small amount of tissue. Using Multi-ABLE, we are able to readily generate a large amount of multi-omic profiles. Having a scalable bioinformatics pipeline to handle these data hence become a limiting factor for widespread adoption of this technology. My research focuses on the development and optimisation of a bioinformatics pipeline to handle these data from raw mass spectrometry output to a normalised feature table that can be used for statistical analysis easily. In this talk, we will review our current development progress, and showcase an application on an animal model of atherosclerosis.

5:30 p.m. 

Speaker: Miss Guoling FU (PhD candidate)
Primary Supervisor: Dr. Jeff Shih Chieh TI
Presentation Title: Human ɑ4a -tubulin confers detyrosinated microtubules increased stability
Abstract: Microtubule subsets with distinct stability differ in tubulin post-translational modifications (PTMs) that also function as the signals guiding cargo transport. However, the molecular mechanism by which microtubule stability correlates to tubulin PTMs remains poorly understood. Here we find that human ɑ4a-tubulin, a highly conserved de-tyrosinated isotype is resistant to enzymic tyrosination. We developed a strategy to site-specifically label recombinant human tubulin with one fluorophore or a biotin to examine microtubules with defined compositions of tubulin isotypes and PTMs. Compared to ɑ1B/β3 microtubules, the filaments assembled with ɑ4a/β3-tubulin is intrinsically more stable and against MCAK-stimulated depolymerization. Further characterization shows the segregation of microtubule stability from the presence of tyrosine at the C-terminus of ɑ-tubulin. Together, our findings reveal the molecular mechanism by which tubulin isotypes can determine the chemical marks along microtubule tracks by regulating microtubule stability and preference to specific PTMs.

ALL ARE WELCOME

Should you have any enquiries, please feel free to contact Miss Cynthia Cheung at 3917 9748.