title: Induction of Wnt/β-catenin signaling in mouse mesenchymal stem cells is associated with activation of the p130 and E2f4 and formation of the p130/Gsk3β/β-catenin complex.
abstract: Proteins p130 and E2f4, members of the retinoblastoma protein (pRb) family/E2F transcription factor family, are the key elements in regulation of cell cycle and differentiation. The functional role of the p130/E2f4 in mesenchymal stem cells (MSC) is unclear. We demonstrate here that activation of the Wnt/β-catenin pathway in mouse MSC is associated with accumulation of active forms of the p130, E2f4, and β-catenin but does not result in inhibition of cell cycle progression. The levels and phosphorylation patterns of p130, E2f4, and β-catenin in MSC do not change during cell cycle progression. This is different from control T98G glyoblastoma cells that accumulated differently phosphorylated forms of the p130 in quiescence, and under active proliferation. In MSC, synchronized at G0/G1 and S cell cycle phases, the p130 and β-catenin physically interact each other, whereas Gsk3β was associated and co-precipitated with both p130 and β-catenin. Our results indicate that Wnt/β-catenin and pRb signal pathways interact with each other and form common p130/Gsk3β/β-catenin complex during MSC cycle progression. Physiological relevance of such complex may be associated with coupling of the cell cycle and differentiation in MSC, which is related to a wide differentiation potential of these stem cells.
authors.affiliation: Laboratory of Cell Pathology, Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia.
authors.forename: Nikolay
authors.initials: N
authors.lastname: Petrov
authors.forename: Olga
authors.initials: O
authors.lastname: Zhidkova
authors.forename: Vladimir
authors.initials: V
authors.lastname: Serikov
authors.forename: Valery
authors.initials: V
authors.lastname: Zenin
authors.forename: Boris
authors.initials: B
authors.lastname: Popov
mesh_terms: D000818:Animals; D002453:Cell Cycle / Q000502:physiology; D045744:Cell Line, Tumor; D050704:E2F4 Transcription Factor / Q000235:genetics / Q000378:metabolism*; D038362:Glycogen Synthase Kinase 3 / Q000235:genetics / Q000378:metabolism*; D000071679:Glycogen Synthase Kinase 3 beta; D057809:HEK293 Cells; D006801:Humans; D008297:Male; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000378:metabolism*; D051379:Mice; D008822:Mice, Transgenic; D046912:Multiprotein Complexes / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation / Q000502:physiology; D050717:Retinoblastoma-Like Protein p130 / Q000235:genetics / Q000378:metabolism*; D051153:Wnt Proteins / Q000235:genetics / Q000378:metabolism*; D060449:Wnt Signaling Pathway / Q000502:physiology*; D051176:beta Catenin / Q000235:genetics / Q000378:metabolism*
chemical_list: D050704:E2F4 Transcription Factor; C493763:E2f4 protein, mouse; D046912:Multiprotein Complexes; C493838:Rbl2 protein, mouse; D050717:Retinoblastoma-Like Protein p130; D051153:Wnt Proteins; D051176:beta Catenin; C000605506:GSK3B protein, human; D000071679:Glycogen Synthase Kinase 3 beta; C000605507:Gsk3b protein, mouse; D038362:Glycogen Synthase Kinase 3