title: Are transforming properties of the bovine papillomavirus E5 protein shared by E5 from high-risk human papillomavirus type 16?
abstract: The E5 proteins of bovine papillomavirus type 1 (BPV-1) and human papillomavirus type 16 (HPV-16) are small (44-83 amino acids), hydrophobic polypeptides that localize to membranes of the Golgi apparatus and endoplasmic reticulum, respectively. While the oncogenic properties of BPV-1 E5 have been characterized in detail, less is known about HPV-16 E5 due to its low expression in mammalian cells. Using codon-optimized HPV-16 E5 DNA, we have generated stable fibroblast cell lines that express equivalent levels of epitope-tagged BPV-1 and HPV-16 E5 proteins. In contrast to BPV-1 E5, HPV-16 E5 does not activate growth factor receptors, phosphoinositide 3-kinase or c-Src, and fails to induce focus formation, although it does promote anchorage-independent growth in soft agar. These variant activities are apparently unrelated to differences in intracellular localization of the E5 proteins since retargeting HPV-16 E5 to the Golgi apparatus does not induce focus formation.
authors.affiliation: Department of Pathology, Georgetown University Medical School, Preclinical Sciences Building, Room GR10C, 3900 Reservoir Road, NW, Box #571432, Washington, DC 20057, USA.
authors.forename: Frank A
authors.initials: FA
authors.lastname: Suprynowicz
authors.forename: Gary L
authors.initials: GL
authors.lastname: Disbrow
authors.forename: Vera
authors.initials: V
authors.lastname: Simic
authors.forename: Richard
authors.initials: R
authors.lastname: Schlegel
mesh_terms: D000818:Animals; D052688:Bovine papillomavirus 1 / Q000235:genetics / Q000378:metabolism; D003062:Codon; D000939:Epitopes / Q000032:analysis; D006801:Humans; D009856:Oncogene Proteins, Viral / Q000737:chemistry* / Q000378:metabolism*; D027383:Papillomaviridae / Q000235:genetics; D017434:Protein Structure, Tertiary; D013329:Structure-Activity Relationship; D000086082:Viroporin Proteins
chemical_list: D003062:Codon; D000939:Epitopes; D009856:Oncogene Proteins, Viral; C083104:E5 protein, Human papillomavirus type 6; C054304:oncogene protein E5, Bovine papillomavirus type 1; C054859:oncogene protein E5, Human papillomavirus type 16; D000086082:Viroporin Proteins