The HSV-1 UL45 gene product is not required for growth in vero cells

Abstract

We have constructed a HSV-1 UL45 null mutant (UL45Δ) by inserting a TK- lacZ cassette into a Bc11 site near the 5′ end of the UL45 gene. A polyclonal antiserum produced to an Escherichia coli trpE:UL45 fusion protein was used to show that an 18-kDa polypeptide corresponding to the predicted UL45 gene product was produced in HSV-1 strain KOS-infected Vero cells but was not detected in UL45Δ-infected Vero cells. The absence of the 18-kDa protein had only a slight effect on viral growth in cell culture, indicating that the UL45 gene product is not essential for growth in Vero cells. However, the burst size of UL45A was smaller than HSV-1 KOS in Vero and HeLa cells. UL45Δ also had a smaller plaque size and an altered plaque morphology