title: Potent Inhibition of Human Cytomegalovirus by Modulation of Cellular SNARE Syntaxin 5.
abstract: Formation of the cytoplasmic viral assembly compartment (cVAC) is an important step for efficient human cytomegalovirus (HCMV) assembly. To do this, the virus must alter and repurpose the normal cellular balance of membrane and protein flux, a process that is not well understood. Although a recent screen identified three viral proteins essential for cVAC formation, less is known about the contribution of cellular factors. We show that HCMV infection increases the protein level of a cellular trafficking factor, syntaxin 5 (STX5), a member of the syntaxin family of SNARE proteins. STX5 is recruited to the cVAC in infected cells and is required for the efficient production of infectious virions. We find that STX5 is important for normal cVAC morphology and the proper localization of viral proteins. A previously identified inhibitor of trafficking, Retro94, causes the mislocalization of STX5, an altered cVAC morphology, and dispersal of viral proteins. The presence of Retro94 results in severely impaired production of infectious virions, with a decrease as great as 5 logs. We show that this inhibition is conserved among different strains of HCMV and the various cell types that support infection, as well as for murine CMV. Thus, our data identify a key cellular trafficking factor important for supporting HCMV infection.
  
  
  OBJECTIVE
  Human cytomegalovirus (HCMV) infection causes severe disease and mortality in immunocompromised individuals, including organ transplant and AIDS patients. In addition, infection of a developing fetus may result in lifelong complications such as deafness and learning disabilities. Understanding in detail the processes involved in HCMV replication is important for developing novel treatments. One of these essential processes, assembly of infectious virions, takes places in the cytoplasmic viral assembly compartment. We identify a cellular protein, syntaxin 5, important for generating this compartment, and show that it is required for the efficient production of infectious virions. We also show that a small molecule that disrupts this protein also significantly reduces the amount of infectious virions that are generated. Thus, by pinpointing a cellular protein that is important in the replication cycle of HCMV, we identified a novel target that can be pursued for therapeutic intervention.
authors: Department of Microbiology and Immunology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania, USA.
authors: Linda
authors: L
authors: Cruz
authors: Department of Microbiology and Immunology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania, USA.
authors: Nicholas T
authors: NT
authors: Streck
authors: Department of Microbiology and Immunology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania, USA.
authors: Kevin
authors: K
authors: Ferguson
authors: Department of Pharmacology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania, USA.
authors: Trisha
authors: T
authors: Desai
authors: Department of Pharmacology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania, USA.
authors: Dhimant H
authors: DH
authors: Desai
authors: Department of Pharmacology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania, USA.
authors: Shantu G
authors: SG
authors: Amin
authors: Department of Microbiology and Immunology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania, USA nbuchkovich@hmc.psu.edu.
authors: Nicholas J
authors: NJ
authors: Buchkovich
mesh_terms: D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure / Q000821:virology; D003587:Cytomegalovirus / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D003593:Cytoplasm / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure / Q000821:virology; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure / Q000821:virology; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure / Q000821:virology; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D054884:Host-Pathogen Interactions; D006801:Humans; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D021381:Protein Transport / Q000187:drug effects; D050765:Qa-SNARE Proteins / Q000235:genetics* / Q000378:metabolism; D011799:Quinazolines / Q000494:pharmacology*; D015398:Signal Transduction; D014771:Virion / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D019065:Virus Assembly / Q000187:drug effects / Q000235:genetics; D000097573:Red Fluorescent Protein
chemical_list: D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins; D050765:Qa-SNARE Proteins; D011799:Quinazolines; D000097573:Red Fluorescent Protein; C000612950:STX6 protein, human
keywords: Golgi apparatus; HCMV; SNARE; assembly; assembly compartment; cytomegalovirus; protein trafficking