title: P68 RNA helicase mediates PDGF-induced epithelial mesenchymal transition by displacing Axin from beta-catenin.
abstract: The nuclear p68 RNA helicase (referred to as p68) is a prototypical member of the DEAD box family of RNA helicases. The protein plays a very important role in early organ development. In the present study, we characterized the tyrosine phosphorylation of p68 under platelet-derived growth factor (PDGF) stimulation. We demonstrated that tyrosine phosphorylation of p68 at Y593 mediated PDGF-stimulated epithelial-mesenchymal transition (EMT). We showed that PDGF treatment led to phosphorylation of p68 at Y593 in the cell nucleus. The Y593-phosphorylated p68 (referred to as phosphor-p68) promotes beta-catenin nuclear translocation via a Wnt-independent pathway. The phosphor-p68 facilitates beta-catenin nuclear translocation by blocking phosphorylation of beta-catenin by GSK-3beta and displacing Axin from beta-catenin. The beta-catenin nuclear translocation and subsequent interaction with the LEF/TCF was required for the EMT process. These data demonstrated a novel mechanism of phosphor-p68 in mediating the growth factor-induced EMT and uncovered a new pathway to promote beta-catenin nuclear translocation.
authors.affiliation: Department of Biology, Georgia State University, University Plaza, Atlanta, GA 30303, USA.
authors.forename: Liuqing
authors.initials: L
authors.lastname: Yang
authors.forename: Chunru
authors.initials: C
authors.lastname: Lin
authors.forename: Zhi-Ren
authors.initials: ZR
authors.lastname: Liu
mesh_terms: D021581:Active Transport, Cell Nucleus / Q000502:physiology; D000595:Amino Acid Sequence; D000818:Animals; D060466:Axin Protein; D002454:Cell Differentiation / Q000502:physiology*; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D048430:Cell Shape; D053487:DEAD-box RNA Helicases / Q000235:genetics / Q000378:metabolism*; D004847:Epithelial Cells / Q000166:cytology / Q000502:physiology*; D006801:Humans; D008648:Mesoderm / Q000166:cytology* / Q000502:physiology; D008969:Molecular Sequence Data; D010766:Phosphorylation; D010982:Platelet-Derived Growth Factor / Q000378:metabolism*; D016315:Proto-Oncogene Proteins c-abl / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology; D051822:T Cell Transcription Factor 1 / Q000235:genetics / Q000378:metabolism; D014443:Tyrosine / Q000378:metabolism; D051153:Wnt Proteins / Q000378:metabolism; D051176:beta Catenin / Q000235:genetics / Q000378:metabolism*
chemical_list: D060466:Axin Protein; D010982:Platelet-Derived Growth Factor; D034741:RNA, Small Interfering; D012097:Repressor Proteins; D051822:T Cell Transcription Factor 1; D051153:Wnt Proteins; D051176:beta Catenin; D014443:Tyrosine; D016315:Proto-Oncogene Proteins c-abl; D053487:DEAD-box RNA Helicases