Shaw M. Akula

Document Type

Dissertation - University Access Only

Award Date

1999

Degree Name

Doctor of Philosophy (PhD)

Department / School

Biology

Abstract

Bovine herpesvirus type 1 (BHV-1) is the major ruminant herpesviruses. BHV-1 infection is the most common respiratory and reproductive infection of cattle resulting in millions of dollars in loss to the cattle industry every year. Latency is a major concern in BHV-1 infection, as the infected animals are life long carriers. The BHV-1 genome is sequenced and the pathogenic changes induced by BHV-1 are well characterized. However, little is known about the phosphorylation events occurring during a productive BHV -1 infection. This dissertation is focused on tyrosine phosphorylation events occurring during BHV-1 infection. This study identified BHV-1 glycoprotein E (gE) as a tyrosine phosphorylated protein by immunoprecipitation. We used a novel approach to study the function of tyrosine phosphorylated gE. The approach involved studying the effect of functional inhibitors on the wild-type virus (BHV-1) and a gE-deletion mutant virus (BHV-1 gEL\.3 .1 ). The tyrosine kinase inhibitors, genistein and tyrphostin, inhibited the tyrosine phosphorylation of gE, as well as, the replication of BHV-1 in vitro. Genistein and tyrphostin did not significantly inhibit the in vitro replication of BHV-lgE~3 .1, suggesting the tyrosine kinase inhibitors to specifically inhibit gE phosphorylation. Tyrosine phosphorylation of gE was identified as an important post-translational modification in vitro BHV-1 replication. These results also indicated that BHV-1 and BHV-lgEA3.l utilized different pathways of infection. The data from this project showed that the naturally available dietary supplement, genistein, to be a potent and selective inhibitor ofBHV-1 infection. Finally, we provided evidence for gE-dependent and independent pathways of the BHV-1 infection. Further, wild-type BHV-1 infection was not affected by cellular F-actin polymerization, while the BHV- 1 gEA3 . l required cellular F-actin polymerization for maximum viral replication. Our results indicated that inhibition ofF-actin altered the distribution pattern of the late protein (gC) during BHV-lgEA3. I but not wild-type BHV-1 infection. We concluded BHV-1 gE assists in the redistribution of gC and perhaps other viral glycoproteins in the actin-independent pathway ofBHV-1 replication. These observations are significant as they add a new dimension to understanding BHV-1 replication and in developing new strategies to counter BHV -1 infection.

Library of Congress Subject Headings

Cattle -- Virus diseases Herpesvirus diseases in animals Phosphorylation Glycoproteins

Format

application/pdf

Number of Pages

121

Publisher

South Dakota State University

Download

Share

COinS