Fully-funded PhD studentship

Start date: October 2013

Applications due: February 25th 2013, 5pm

Title: Molecular mechanisms of enveloped virus egress

After replication viruses face a logistical challenge: How do they ensure progeny virions are efficiently released from host cells? While human pathogens such as Herpes Simplex Virus 1 (HSV-1) are known to subvert host-cell intracellular membrane trafficking pathways in order to leave infected cells, little is known about the molecular mechanisms used to achieve this. This study will use a combination of biochemical, biophysical and structural techniques (including protein X-ray crystallography) to define in atomic detail the interactions between host cell and virus proteins that enable enveloped viruses to exit infected cells and thereby spread the infection to new hosts.

Enveloped viruses subvert host-cell membrane trafficking to ensure that progeny virions are efficiently released from infected cells. While much is known about how viruses such as HIV or Rabies virus recruit the host-cell ESCRT machinery to bud from the plasma membrane, relatively little is known about the exit mechanism used by large double-stranded DNA viruses. These viruses acquire a double envelope at an intracellular organelle such as the trans-Golgi or recycling endosomes, thereby becoming a virus inside a transport vesicle, and are transported to the cell surface whereupon they fuse with the plasma membrane, expelling a singly-enveloped virus to the extracellular milieu. Like ESCRT-mediated virus budding, fusion of virus-containing vesicles with the plasma membrane will require the concerted action of host cell membrane-trafficking machinery. This project aims to determine the host-cell factors required for release of Herpes Simplex Virus 1 (HSV-1) at the plasma membrane of infected cells.

Interactions between virus proteins and the host-cell trafficking machinery will be identified by yeast-two-hybrid library screening and GST pull-downs with mass spectrometry. Interactions identified with these screening techniques will be validated using recombinant components produced by E. coli or mammalian cell culture and the minimal regions required for binding will be mapped using a high-throughput in vitro transcription/translation pull-down assay. Interactions thus validated will be further characterised using biophysical techniques such as isothermal titration calorimetry or surface plasmon resonance. Complexes of these purified recombinant proteins will be subjected to crystallisation trials and, should these prove successful, structures will be determined by X-ray crystallography.

The project will be performed in collaboration with Dr Colin Crump (Division of Virology) during both the initial screening procedures and to validate identified interactions in the context of cellular infection.

Eligibility and details on how to apply are available here.