Date: Friday, 24 May 2019

Venue: Seminar Room 4, G/F
Laboratory Block, Faculty of Medicine Building
21 Sassoon Road, Hong Kong

Time: 5:00 p.m.

Title: The role of Pax1 in the etiology of adolescent idiopathic scoliosis
Speaker: Mrs. VIMALAGOPALAN Divya (MPhil candidate)

Summary:
AIS is the commonest form of scoliosis affecting children with unknown etiology. Researchers believe the involvement of genetics in AIS pathogenesis and GWAS study on humans has listed PAX1 as a risk factor. Pax1 - transcription factor known to regulate the development of vertebral column and intervertebral disc. During somitogenesis Pax1 interpret the notochordal signals and helps in dorso-ventral specification of cells to develop the ventral structures and the IVD. Each compartment of the IVD such as nucleus nulposus (NP), annular fibrosis (AF) and endplate synergistically withstands the axial load where loss of integrity in either of its compartments may trigger an altered stress response and initiate an initial event of curvature.
We are interested in studying the effects of reduced Pax1 expression in postnatal IVD homeostasis. Pax1-/- mutants show congenital scoliotic phenotype with full penetrance while Pax1+/- appear normal in gross appearance.
Our results show Pax1 deficiency dysregulates the IVD development leading to morphological changes including decreased NP cellularity, increased mineralization, loss of lamellar AF, loss/ discontinuity in the NP/AF boundary and disorganized growth plate columns. With these findings we further hypothesis that reduced Pax1 expression together with an external environmental factor may initiate IVD dysregulation leading to initiation and progression of AIS curvature.

Title: The structural studies of bromodomain proteins in complex with histone crotonylation peptides
Speaker: Miss WAN Wenjin (MPhil candidate)

Summary:
Histone modifications are the key epigenetic regulations that play important roles in various cellular activities. Histone lysine crotonylation (Kcr), firstly discovered in 2011, are evolutionary conserved in eukaryotic cells in a wide range of species. Histone Kcr were found to mainly associate with gene promoters and enhancers and stimulate gene expression. Bromodomains are protein interaction modules that were known as acetylation readers. Our lab discovered that bromodomains could also bind to histone crotonylation peptides. According to the microarray results, I chose the bromodomain proteins that have strongest binding with crotonylation peptides to further study their binding patterns through X-ray crystallography.

ALL ARE WELCOME