Mapping the proteins of the herpes simplex virus type 1 capsid

Adamson, Walt Eric (2006) Mapping the proteins of the herpes simplex virus type 1 capsid. PhD thesis, University of Glasgow.

Abstract

The aims of the work presented in this thesis were to use a variety of mutagenesis techniques to investigate the proteins of the HSV-1 capsid.

Triplexes are heterotrimers formed by two proteins in a 1:2 stoichiometry. The single-copy protein is called VP19C, and the dimeric protein is VP23. Insertional and deletional mutagenesis was carried out on VP19C and the effects of the mutations on virus growth and capsid assembly were examined. Insertional mutagenesis showed that VP19C can be divided into three regions with respect to their ability to tolerate five amino acid insertions, with two regions of approximately 100 amino acids at the N- and C-terminal regions of the protein being more tolerant of such insertions than a ~350 amino acid central region. The N-terminal ~100 amino acids of the protein, which are particularly insensitive to insertional mutagenesis, correspond to a region that is poorly conserved among herpesviruses. Some, but not all, severely disabled mutants were compromised in their ability to bind VP23 and VP5.

Analysis of deletional mutants revealed the presence of an unusual nuclear localisation signal (NLS) near the N-terminus of VP19C. This was mapped to a 33 amino acid region by fusion of specific sequences to a green fluorescent protein (GFP) marker.

By replacing the endogenous NLS with that from the simian virus 40 (SV40) large T antigen, we were able to show that the first 45 amino acids of VP19C were not essential for assembly of functional capsids and infectious virus particles. However, removing the first 63 amino acids resulted in the formation of aberrant capsids and prevented virus growth, suggesting that the poorly-conserved N-terminal sequences have some as-yet-unidentified function.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Subjects: Q Science > QR Microbiology > QR355 Virology
• Colleges/Schools: College of Medical Veterinary and Life Sciences > School of Life Sciences > Life Sciences Biomolecular Science
• Supervisor's Name: Rixon, Dr. Frazer
• Date of Award: 2006
• Depositing User: Angi Shields
• Unique ID: glathesis:2006-3963
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 07 Feb 2013 12:02
• Last Modified: 07 Feb 2013 12:02
• URI: https://theses.gla.ac.uk/id/eprint/3963