title: Identification and characterization of the CRPV E7 protein expressed in COS-7 cells.
abstract: The papillomavirus E7 protein may play an important role in oncogenesis as it is the major viral protein present in human cervical cancer-derived cell lines. Because of the relevance of the cottontail rabbit papillomavirus (CRPV) system for the study of viral-induced malignancies, we characterized its E7 protein expressed by a heterologous strong promoter. An E7-specific antiserum was obtained by immunizing rabbits with a Trp E-E7 fusion protein containing the 88 carboxyl-terminal amino acids of E7. This antiserum specifically precipitated from [35S]cysteine but not from 32PO4-labeled transiently transfected COS-7 cells a 14-kDa protein. The protein was present only in the soluble cytoplasmic fraction and exhibited a heterogeneous sedimentation rate in nondenaturing glycerol gradients.
authors.affiliation: Department of Microbiology and Immunology, School of Medicine, University of California, Los Angeles 90024.
authors.forename: M S
authors.initials: MS
authors.lastname: Barbosa
authors.forename: F O
authors.initials: FO
authors.lastname: Wettstein
mesh_terms: D000818:Animals; D002460:Cell Line; D002472:Cell Transformation, Viral; D002522:Chlorocebus aethiops; D012777:Cottontail rabbit papillomavirus / Q000032:analysis* / Q000502:physiology; D005347:Fibroblasts; D007668:Kidney; D027383:Papillomaviridae / Q000032:analysis*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D013347:Subcellular Fractions / Q000032:analysis; D014764:Viral Proteins / Q000302:isolation & purification*
chemical_list: D011993:Recombinant Fusion Proteins; D014764:Viral Proteins