Date: Friday, 4 March 2022

Time: 5:00 p.m. - 6:00 p.m.

Via Zoom: https://hku.zoom.us/j/93758672826?pwd=R0Q5S290R1RyMUZkcHFpQm5xenNEdz09

Meeting ID: 937 5867 2826

Password: 567168

5:00 p.m.

Presenter: Ms. Daisylyn Senna Young TAN, PhD candidate
Primary Supervisor: Dr. Ralf JAUCH
Presentation Title: Decoding how reprogramming transcription factors activate epigenetically silenced DNA
Abstract: DNA binding transcription factors (TFs) can be categorized as pioneer TFs. Pioneers are thought to have a unique ability to bind and activate epigenetically silenced genes. Reprogramming factors such as OCT4 can indeed bind silenced chromatin such as methylated DNA or DNA compacted by nucleosome core particles. However, biochemical evidence of how OCT4 directly binds silenced DNA is sparse. Here, we study the binding of OCT4 and BRN2 to methylated DNA and using purified proteins and structural modelling. We compare OCT4 with BRN2, a POU family member with dissimilar functions in cell fate reprogramming. By comparing binding profiles of OCT4 with BRN2, we deduce the domains, configuration and sequence elements required for OCT4 to target silenced DNA through methylation.

5:30 p.m.

Presenter: Mr. Rajesh RANGANATHAN, MPhil candidate
Primary Supervisor: Dr. You-qiang SONG
Presentation Title: DNA repair hotspots, polymorphisms of BIN1, CLU and TP53INP1 and the risk of late onset Alzheimer’s disease
Abstract: Recently Reid et al. (2021) and Wu et al. (2021) showed in experiments with human embryonic stem-cell induced neurons that DNA repair is enriched at well-defined hotspots that protect essential genes and that the proteins binding to these hotspots are enriched in Alzheimer’s Disease as well. Our study shows that several of these hotspots overlap with single nucleotide polymorphisms (SNPs) and gene regulatory regions identified in previous AD GWAS studies. Specifically, SNP rs78710909 in the enhancer region GH02J127099 differentially binds the TF SP2 and may contribute to the changes in expression observed in BIN1 gene in AD. Similarly, the SNP rs896852 in the locus of AD GWAS SNP, rs896855, is found in the enhancer region GH08J094946, differentially binds the TF NRF1 and may contribute to changes in the expression of TP3INP1 gene in AD.  So this study could provide useful new insights into the potential mechanisms on how the expression of the key genes BIN1, CLU and TP53INP1 is altered in AD.

ALL ARE WELCOME

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