Analysis of Select Herpes Simplex Virus 1 (HSV-1) Proteins for Restriction of Human Immunodeficiency Virus Type 1 (HIV-1): HSV-1 gM Protein Potently Restricts HIV-1 by Preventing Intracellular Transport and Processing of Env gp160.

teins encoded by viruses that impair or shutdown specific host cell functions during replication can be used as probes to identify potential proteins/pathways used in the replication of viruses from other families. We screened nine proteins from herpes simplex virus type 1 (HSV-1) for the ability to enhance or restrict human immunodeficiency virus type 1 (HIV-1) replication. We show that several HSV-1 proteins (glycoprotein M (gM), US3 and UL24) potently restricted the replication of HIV-1. Unlike UL24 and US3, which reduced viral protein synthesis, we observed that gM restriction of HIV-1 occurred through interference of the processing and transport of gp160, resulting in a significantly reduced level of mature gp120/gp41 released from cells. Finally, we show that an HSV-1 gM mutant lacking the majority of the C-terminal domain (HA-gM[Δ345-473]) restricted neither gp160 processing nor the release of infectious virus. These studies identify and show that proteins from heterologous viruses restrict viruses through novel pathways.