HSV1_Single_Molecule · Single molecule imaging of herpes simplex virus type 1 DNA replication

Herpes simplex virus type 1 (HSV-1) is a widespread and well-known pathogen. However, we still lack a complete understanding of the mechanism of HSV-1 genome replication. We propose to revisit long-standing questions of the HSV-1 genome replication mechanism using cutting-edge single molecule imaging techniques. This approach enables the detection of transient structures and heterogeneous behavior, leading to further crucial insights into this fundamental process. The current model for HSV-1 genome replication comprises an origin-dependent followed by an origin-independent stage. Whereas we do have evidence and a good understanding of the origin-dependent phase, we completely lack evidence for the proposed structures of the origin-independent phase. Thus, in the proposed project we want to study aspects of the origin-dependent replication phase. Specifically, we want to reveal the role of the HSV-1 origin binding protein UL9 during replication as this protein was proposed to act as a switch from the first to the second stage. It has been shown that UL9 is an essential protein during the origin-dependent stage but dispensable and even inhibitory during the second, origin-independent stage. We here propose to use single-molecule imaging techniques to reveal the inhibitory effect of UL9 on HSV-1 mediated replication and to further characterize the specific conditions of UL9 binding to the origins of replication.