Effects of mumps matrix protein mutations on efficiency of particle production and interaction with viral nucleocapsid protein
Correll, Helen May
Area of Honors:
Veterinary and Biomedical Sciences
Bachelor of Science
Anthony Paul Schmitt, Thesis Supervisor Dr. Lester C Griel Jr., Honors Advisor
Mumps virus mutations
The mumps virus is a paramyxovirus that infects humans and can cause disease, with possible lethal or long-lasting side effects. Although a vaccine for this virus was developed, it has recently become relevant again with outbreaks occurring even in countries with comprehensive vaccinations. The matrix protein encoded in the MuV genome is thought to organize viral assembly and budding by its interaction with viral nucleocapsid protein and glycoproteins. The mumps matrix protein along with nucleocapsid protein and a glycoprotein, fusion protein, were previously found to be sufficient for particle production in vitro. This thesis shows that upon certain sequence insertions into the MuV M protein, efficient particle production can still be seen, but the dependence on NP protein for particle production varies. The amount of charged residues found in the inserted sequence, along with the length of insertion, both seem to play a role in mutants ability to produce virus-like particles in the absence of NP protein. The mutant M proteins were found to have a slower rate of degradation in cells when compared to wildtype M, which could provide an explanation for this varied phenotype. This slower degradation rate was also seen in cells when both wildtype M and NP were expressed, indicating that interaction between NP and M stabilizes M in cells similar to the stabilization of mutant M constructs. These findings suggest different roles of the matrix protein, that when varied by mutation, shows a NP independent phenotype for particle production.