Synthesis, phosphorylation, and nuclear localization of human papillomavirus E7 protein in Schizosaccharomyces pombe.
The complete E7 protein-encoding open reading frame of human papillomavirus type 16 (HPV-16) was expressed in the fission yeast Schizosaccharomyces pombe, under the control of a cloned yeast promoter. The HPV-16 E7 protein synthesized in S. pombe is a 17-kDa phosphoprotein which is recognized by anti-E7 antibodies (raised in rabbits against E7 fusion protein produced in Escherichia coli). The mobility during sodium dodecyl sulfate-polyacrylamide-gel electrophoresis of native E7 phosphoprotein synthesized in S. pombe is identical to that of the E7 phosphoprotein immunoprecipitated from human CaSki cells. Immunofluorescence staining showed that HPV-16 E7 phosphoprotein is localized in the nuclei of transformed S. pombe. These results indicate that E7 protein synthesized by S. pombe is apparently indistinguishable from HPV-16 E7 protein synthesized in higher eukaryotic cells expressing genes of HPV-16, and also that the phosphorylated, nuclear HPV-16 E7 protein is synthesized in S. pombe in a form compatible with its biological activity.
Tommasino
M
M
Molecular Virology, Sclavo Research Centre, Siena, Italy.
Contorni
M
M
Scarlato
V
V
Bugnoli
M
M
Maundrell
K
K
Cavalieri
F
F
D000818:Animals; D001483:Base Sequence; D002467:Cell Nucleus / Q000648:ultrastructure; D005455:Fluorescent Antibody Technique; D006801:Humans; D008969:Molecular Sequence Data; D009856:Oncogene Proteins, Viral / Q000096:biosynthesis / Q000235:genetics*; D016366:Open Reading Frames; D027383:Papillomaviridae / Q000235:genetics; D010750:Phosphoproteins / Q000096:biosynthesis / Q000235:genetics*; D010766:Phosphorylation; D011401:Promoter Regions, Genetic; D014176:Protein Biosynthesis; D011817:Rabbits; D012568:Schizosaccharomyces / Q000235:genetics* / Q000648:ultrastructure; D014158:Transcription, Genetic
D009856:Oncogene Proteins, Viral; D010750:Phosphoproteins; C066076:oncogene protein E7, Human papillomavirus type 8