title: Unexpected role for p19INK4d in posttranscriptional regulation of GATA1 and modulation of human terminal erythropoiesis.
abstract: Terminal erythroid differentiation is tightly coordinated with cell-cycle exit, which is regulated by cyclins, cyclin-dependent kinases, and cyclin-dependent kinase inhibitors (CDKI), yet their roles in erythropoiesis remain to be fully defined. We show here that p19INK4d, a member of CDKI family, is abundantly expressed in erythroblasts and that p19INK4dknockdown delayed erythroid differentiation, inhibited cell growth, and led to increased apoptosis and generation of abnormally nucleated late-stage erythroblasts. Unexpectedly, p19INK4dknockdown did not affect cell cycle. Rather, it led to decreased expression of GATA1 protein. Importantly, the differentiation and nuclear defects were rescued by ectopic expression of GATA1. Because the GATA1 protein is protected by nuclear heat shock protein family (HSP) member HSP70, we examined the effects of p19INK4dknockdown on HSP70 and found that p19INK4dknockdown led to decreased expression of HSP70 and its nuclear localization. The reduced levels of HSP70 are the result of reduced extracellular signal-regulated kinase (ERK) activation. Further biochemical analysis revealed that p19INK4ddirectly binds to Raf kinase inhibitor PEBP1 and that p19INK4dknockdown increased the expression of PEBP1, which in turn led to reduced ERK activation. Thus we have identified an unexpected role for p19INK4dvia a novel PEBP1-p-ERK-HSP70-GATA1 pathway. These findings are likely to have implications for improved understanding of disordered erythropoiesis.
authors.affiliation: The State Key Laboratory of Medical Genetics & School of Life Sciences, Central South University, Changsha, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Han
authors.affiliation: The State Key Laboratory of Medical Genetics & School of Life Sciences, Central South University, Changsha, China.|Laboratory of Membrane Biology, New York Blood Center, New York, NY.
authors.forename: Jieying
authors.initials: J
authors.lastname: Zhang
authors.affiliation: The State Key Laboratory of Medical Genetics & School of Life Sciences, Central South University, Changsha, China.
authors.forename: Yuanliang
authors.initials: Y
authors.lastname: Peng
authors.affiliation: Xiangya Hospital, Central South University, Changsha, China.
authors.forename: Minyuan
authors.initials: M
authors.lastname: Peng
authors.affiliation: The State Key Laboratory of Medical Genetics & School of Life Sciences, Central South University, Changsha, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Chen
authors.affiliation: The State Key Laboratory of Medical Genetics & School of Life Sciences, Central South University, Changsha, China.
authors.forename: Huiyong
authors.initials: H
authors.lastname: Chen
authors.affiliation: Xiangya Hospital, Central South University, Changsha, China.
authors.forename: Jianhui
authors.initials: J
authors.lastname: Song
authors.affiliation: Key Laboratory of Experimental Hematology, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Science & Peking Union Medical College, Tianjin, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Hu
authors.affiliation: Molecular Science and Biomedicine Laboratory, State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Biology, College of Chemistry and Chemical Engineering, Hunan University, Changsha, China.
authors.forename: Mao
authors.initials: M
authors.lastname: Ye
authors.affiliation: Molecular Science and Biomedicine Laboratory, State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Biology, College of Chemistry and Chemical Engineering, Hunan University, Changsha, China.
authors.forename: Jianglin
authors.initials: J
authors.lastname: Li
authors.affiliation: Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA.|Division of Hematology/Oncology, Boston Children's Hospital and Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA.
authors.forename: Vijay G
authors.initials: VG
authors.lastname: Sankaran
authors.affiliation: Red Cell Physiology Laboratory, New York Blood Center, New York, NY; and.
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Hillyer
authors.affiliation: Red Cell Physiology Laboratory, New York Blood Center, New York, NY; and.
authors.forename: Narla
authors.initials: N
authors.lastname: Mohandas
authors.affiliation: Laboratory of Membrane Biology, New York Blood Center, New York, NY.|College of Life Sciences, Zhengzhou University, Zhengzhou, China.
authors.forename: Xiuli
authors.initials: X
authors.lastname: An
authors.affiliation: The State Key Laboratory of Medical Genetics & School of Life Sciences, Central South University, Changsha, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Liu
mesh_terms: D015153:Blotting, Western; D002478:Cells, Cultured; D050764:Cyclin-Dependent Kinase Inhibitor p19 / Q000378:metabolism*; D004920:Erythropoiesis / Q000502:physiology*; D005312:Fetal Blood; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D050982:GATA1 Transcription Factor / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000502:physiology*; D055785:Gene Knockdown Techniques; D006801:Humans; D047468:Immunoprecipitation; D016133:Polymerase Chain Reaction; D015398:Signal Transduction / Q000502:physiology
chemical_list: C493974:CDKN2D protein, human; D050764:Cyclin-Dependent Kinase Inhibitor p19; D050982:GATA1 Transcription Factor; C494688:GATA1 protein, human