Investigation of the Interaction Between Two Herpes Simplex Type 1 Viral Capsid Proteins: the Binding of VP5 and VP22a
Cavagnol, Robert M.
MetadataShow full item record
The herpes simplex virus contains double-stranded DNA surrounded by an icosahedral capsid structure that is composed of seven structural proteins: VPS, VP19c, VP21, VP22a, VP23, VP24, and VP26. These proteins are encoded by six genes (UL18, UL19, UL26, UL26.S, UL3S, and UL38), each having been identified and isolated. The capsid itself is composed of two domains: an outer shell and an inner scaffold structure. The formation of the capsid is believed to occur with the scaffold assembling first and the shell forming around it. DNA is then packaged into the capsid, it buds out of the nucleus and forms a mature virion. The capsid assembly reaction is essential to the development of an infectious particle (Gibson et al., 1972). Furthermore, it has been shown that VPS, which comprises about 70% of the outer shell, interacts with the major constituent of the scaffold structure, VP22a (Thomsen et al .. , 1994). The interaction between VPS and VP22a is the focus of this investigation. Analysis of VP5 and VP22a involved the utilization of two individual protein systems. Recombinant viruses were created using the baculovirus system and used to infect insect cells that produced the desired proteins. These proteins were isolated and analyzed using co-immunoprecipitation, in vitro capsid assembly, and in vivo capsid assembly reactions. Protein interaction was also tested using the yeast two-hybrid system. Cells were first plated onto agar lacking uracil and then assayed for the production of 𝛽-galactosidase. Growth on the agar without uracil and production of 𝛽-galactosidase both depended upon the interaction of the two proteins.