title: Granulocytic differentiation of myeloid progenitor cells by p130, the retinoblastoma tumor suppressor homologue.
abstract: The retinoblastoma protein (pRB) and the related pocket proteins, p107 and p130, play crucial roles in mammalian cell cycle control. Recent studies indicate that these pocket proteins are also involved in cellular differentiation processes. We demonstrate in this work that the pRB-related p130 selectively accumulates during the in vitro differentiation of the myeloid progenitor cell, 32Dcl3, into granulocyte in response to granulocyte-colony stimulating factor (G-CSF). This G-CSF-dependent granulocytic differentiation is blocked by the adenovirus E1A oncoprotein, which binds to and inactivates the pRB family of pocket proteins including p130. Furthermore, enforced overexpression of p130 but not pRB inhibits the myeloid cell proliferation that is concomitantly associated with granulocytic differentiation morphologically characterized by nuclear segmentation. However, simple G1-cell cycle arrest induced by cytokine deprivation or ectopic overexpression of the p27 cyclin-dependent kinase inhibitor, or inhibition of E2F activities by dominant negative DP-1 is not sufficient to trigger granulocytic differentiation. The differentiation-promoting activity of p130 in myeloid cells requires both the pocket domain and the spacer domain. Our results indicate that the pRB-related p130 plays a critical role in myeloid cell differentiation and suggest that coupling of cell cycle exit with the cellular differentiation program may be specifically achieved by p130.
authors.affiliation: Department of Viral Oncology, Cancer Institute, Japanese Foundation for Cancer Research, Tokyo, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Mori
authors.forename: H
authors.initials: H
authors.lastname: Higashi
authors.forename: Y
authors.initials: Y
authors.lastname: Hoshikawa
authors.forename: M
authors.initials: M
authors.lastname: Imamura
authors.forename: M
authors.initials: M
authors.lastname: Asaka
authors.forename: M
authors.initials: M
authors.lastname: Hatakeyama
mesh_terms: D017500:Adenovirus E1A Proteins / Q000502:physiology; D000818:Animals; D042846:CDC2-CDC28 Kinases; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D019927:Cyclin E / Q000378:metabolism; D051357:Cyclin-Dependent Kinase 2; D018844:Cyclin-Dependent Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D004268:DNA-Binding Proteins; D050684:E2F Transcription Factors; D016193:G1 Phase / Q000187:drug effects / Q000502:physiology*; D016179:Granulocyte Colony-Stimulating Factor / Q000494:pharmacology*; D006098:Granulocytes / Q000166:cytology*; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000187:drug effects; D051379:Mice; D010750:Phosphoproteins / Q000737:chemistry / Q000502:physiology*; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D017434:Protein Structure, Tertiary; D011506:Proteins; D011993:Recombinant Fusion Proteins / Q000502:physiology; D016160:Retinoblastoma Protein / Q000502:physiology; D056465:Retinoblastoma-Binding Protein 1; D050717:Retinoblastoma-Like Protein p130; D050680:Transcription Factor DP1; D014157:Transcription Factors / Q000502:physiology
chemical_list: D017500:Adenovirus E1A Proteins; C533431:Arid4a protein, mouse; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D019927:Cyclin E; D004268:DNA-Binding Proteins; D050684:E2F Transcription Factors; D010750:Phosphoproteins; D011506:Proteins; C493838:Rbl2 protein, mouse; D011993:Recombinant Fusion Proteins; D016160:Retinoblastoma Protein; D056465:Retinoblastoma-Binding Protein 1; D050717:Retinoblastoma-Like Protein p130; C493736:Tfdp1 protein, mouse; D050680:Transcription Factor DP1; D014157:Transcription Factors; D016179:Granulocyte Colony-Stimulating Factor; D017346:Protein Serine-Threonine Kinases; D042846:CDC2-CDC28 Kinases; C495893:Cdk2 protein, mouse; D051357:Cyclin-Dependent Kinase 2; D018844:Cyclin-Dependent Kinases