title: The E5 proteins.
abstract: The E5 proteins are short transmembrane proteins encoded by many animal and human papillomaviruses. These proteins display transforming activity in cultured cells and animals, and they presumably also play a role in the productive virus life cycle. The E5 proteins are thought to act by modulating the activity of cellular proteins. Here, we describe the biological activities of the best-studied E5 proteins and discuss the evidence implicating specific protein targets and pathways in mediating these activities. The primary target of the 44-amino acid BPV1 E5 protein is the PDGF β receptor, whereas the EGF receptor appears to be an important target of the 83-amino acid HPV16 E5 protein. Both E5 proteins also bind to the vacuolar ATPase and affect MHC class I expression and cell-cell communication. Continued studies of the E5 proteins will elucidate important aspects of transmembrane protein-protein interactions, cellular signal transduction, cell biology, virus replication, and tumorigenesis.
authors.affiliation: Department of Genetics, Yale School of Medicine, USA; Department of Therapeutic Radiology, Yale School of Medicine, USA; Department of Molecular Biophysics & Biochemistry, Yale University, USA; Yale Cancer Center, USA. Electronic address: daniel.dimaio@yale.edu.
authors.forename: Daniel
authors.initials: D
authors.lastname: DiMaio
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Petti
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis; D002471:Cell Transformation, Neoplastic / Q000473:pathology*; D052687:Deltapapillomavirus / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D054884:Host-Pathogen Interactions; D057131:Immune Evasion; D008969:Molecular Sequence Data; D009154:Mutation; D009856:Oncogene Proteins, Viral / Q000235:genetics / Q000378:metabolism*; D030361:Papillomavirus Infections / Q000378:metabolism; D020797:Receptor, Platelet-Derived Growth Factor beta / Q000378:metabolism; D014779:Virus Replication
chemical_list: D009856:Oncogene Proteins, Viral; C054304:oncogene protein E5, Bovine papillomavirus type 1; D020797:Receptor, Platelet-Derived Growth Factor beta
keywords: Cervical cancer; EGF receptor; HPV; PDGF receptor; Papillomaviruses; Transmembrane proteins; Vacuolar ATPase