title: The location of endogenous wild-type p53 protein in 293T and HEK293 cells expressing low-risk HPV-6E6 fusion protein with GFP.
abstract: The mechanism underlining human papillomaviruses (HPVs) causing cancer has been studied extensively, and it was concluded that the high-risk HPVs' E6 targeted and degraded tumor suppressor protein p53, leading to infected cells malignant transformation. In contrast, the low-risk HPVs only cause proliferative but non-invasive lesions of infected epithelia. Therefore, we hypothesized that low-risk HPVs' E6 might interact with p53 in a different pattern. We used a mammalian green fluorescent protein (GFP) expression system to express HPV-18E6 and HPV-6E6 fusion proteins in wild-type (wt) p53 cell lines, 293T and HEK293 cells, to investigate the traffic and location of E6s and p53. The results indicated GFP-18E6 was mainly expressed in nucleus, whereas GFP-6E6 was expressed exclusively in cytoplasm. Endogenous wt p53 was shown to be localized in the nuclei of cells transfected with GFP- 18E6. Interestingly, for the first time, we observed that p53 was trapped in the cytoplasm and never translocated into the cell nuclei transfected with GFP-6E6. In conclusion, HPV-6E6 was responsible for the cytoplasmic localization of p53. Therefore, our experiments provide a new insight into the pathogenesis of HPV.
authors.affiliation: State key Laboratory for Infectious Disease Prevention and Control, National Institute for Infectious Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China. sunlina1977@yahoo.com.cn
authors.forename: Lina
authors.initials: L
authors.lastname: Sun
authors.forename: Xinxin
authors.initials: X
authors.lastname: Shen
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu
authors.forename: Ge
authors.initials: G
authors.lastname: Zhang
authors.forename: Jianchun
authors.initials: J
authors.lastname: Wei
authors.forename: Huijuan
authors.initials: H
authors.lastname: Zhang
authors.forename: Enming
authors.initials: E
authors.lastname: Zhang
authors.forename: Fengqin
authors.initials: F
authors.lastname: Ma
mesh_terms: D002460:Cell Line; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007668:Kidney / Q000378:metabolism*; D009856:Oncogene Proteins, Viral / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism*; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D013347:Subcellular Fractions / Q000378:metabolism*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
chemical_list: C068651:E6 protein, Human papillomavirus type 16; D009856:Oncogene Proteins, Viral; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D016159:Tumor Suppressor Protein p53; D049452:Green Fluorescent Proteins