Flavivirus Capsid Protein

Start Date & Time: 
Friday, 2 August, 2013 - 15:00
End Date & Time: 
Friday, 2 August, 2013 - 16:00

Duke-NUS, Amphitheatre

Speaker Details: 

Mah-Lee Ng

Professor, Department of Microbiology, NUS

Director, Electron Microscopy Unit, Yong Loo Lin School of Medicine, NUS


Flavivirus capsid (C) protein is a small structural protein. The main function of C protein is to package viral RNA into the nucleocapsid core during viral assembly. The positively-charged C protein binds to negatively-charged viral RNA, homo-oligomerizes and assembles into cage-like nucleocapsid.  

Our study demonstrated that C protein-RNA association was regulated by the phosphorylation / dephosphorylation of C protein. Phosphorylated C protein was unable to bind to viral RNA but it was transported into the cell nucleus via direct interaction with importin proteins.High throughput protoarray analysis using purified biotinylated full-length C protein unravelled several novel host interacting proteins that are involved in modulating ribosomal RNA processing, cell cycle control, apoptosis and other signal transduction pathways. Dengue virus production was greatly reduced when host cells were arrested at G1-phase during infection.  

In addition to interactions with nuclear proteins, flaviviral C protein also interacts with cytoplasmic proteins during replication process. One such example is the specific interaction with human Sec3 protein (hSec3p). hSec3p is an exocyst component found to be a host anti-viral response against the infecting virus but the C protein was found to be able to abolish this response. 

Most of the anti-viral research targets viral envelope or the enzymatic activity of non-structural proteins such as NS3/NS5 proteins. Our study pinpointed C protein as one of the potential anti-viral target because of its multifunctional roles in nucleocapsid formation and C -host protein interplay. 


Professor Mah-Lee Ng is Professor of Department of Microbiology and is concurrently the Director of the Electron Microscopy Unit, Yong Loo Lin School of Medicine, NUS.

She has mentored/mentoring 50 post-graduate students and over 70 B Sc (Honours) students in addition to her teaching for the undergraduate Science and Dental students. Her primary research interest is on the pathogenesis and anti-viral strategies for flavivirus infections with focus on dengue and West Nile viruses.

Other strength of her research team is on innovative imaging techniques for biomedical research. Professor Ng has been successful in obtaining several external competitive grants for her research. She has over 110 international publications on her research and has given numerous invited lectures at conferences.


Assistant Professor Manoj N Krishnan

Program in Emerging Infectious Diseases

Contact Person: 

Ms Serene Chee

Email: serene.chee@duke-nus.edu.sg