title: Connexin 43 expression is downregulated in raft cultures of human keratinocytes expressing the human papillomavirus type 16 E5 protein.
abstract: A decrease in gap junction-mediated cell-to-cell communication has previously been observed in monolayer cultures of human keratinocytes (HaCaT cells) expressing the human papillomavirus type 16 E5 (HPV16 E5) gene and attributed to the reduced phosphorylation of connexin 43, the most abundant connexin in HaCaT cells. In line with this observation, we have now analyzed the effect of HPV16 E5 on connexin 43 expression in raft cultures produced by transfected HaCaT cells. These keratinocytes transcribe HPV16 E5 under the control of a dexamethasone-inducible promoter. Our results show that treatment with dexamethasone leads to an almost complete disappearance of connexin 43 in rafts expressing the E5 gene but not in control rafts. In our study we discuss the possible effects of this downregulation on cell-cell communication and cellular malignant transformation.
authors.affiliation: Deutsches Krebsforschungszentrum, Heidelberg, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Tomakidi
authors.forename: H
authors.initials: H
authors.lastname: Cheng
authors.forename: A
authors.initials: A
authors.lastname: Kohl
authors.forename: G
authors.initials: G
authors.lastname: Komposch
authors.forename: A
authors.initials: A
authors.lastname: Alonso
mesh_terms: D018929:Cell Culture Techniques; D002460:Cell Line; D002478:Cells, Cultured; D018031:Connexin 43 / Q000276:immunology / Q000378:metabolism*; D003907:Dexamethasone / Q000494:pharmacology; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D017403:In Situ Hybridization; D015603:Keratinocytes / Q000187:drug effects / Q000378:metabolism* / Q000821:virology*; D009856:Oncogene Proteins, Viral / Q000235:genetics* / Q000502:physiology; D012333:RNA, Messenger / Q000032:analysis; D014162:Transfection; D000086082:Viroporin Proteins
chemical_list: D018031:Connexin 43; D003907:Dexamethasone; D009856:Oncogene Proteins, Viral; D012333:RNA, Messenger; C054859:oncogene protein E5, Human papillomavirus type 16; D000086082:Viroporin Proteins