NF-E2p18/mafK is required in DMSO-induced differentiation of Friend erythroleukemia cells by enhancing NF-E2 activity

Francastel, Claire; Poindessous-Jazat, Virginie; Augery-Bourget, Yvette; Robert-Lézénès, J

doi:10.1038/sj.leu.2400552

Cited by 25 publications

(19 citation statements)

References 4 publications

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“…As shown, the amounts of both the protein and mRNA of p45 were increased after DMSO induction as reported previously (30). Significantly, the increase of the level of p45 protein in MEL cells during differentiation was in parallel with the drastic decreases of both the level of p45 phosphorylated at S157 or P-p45(S157), and that of P-JNK (Fig.…”

Section: P-jnk-mediated Turnover and Differential Chromatin-binding Osupporting

confidence: 61%

JNK-mediated turnover and stabilization of the transcription factor p45/NF-E2 during differentiation of murine erythroleukemia cells

Lee

Shyu

Hsu

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

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Regulation of the homeostatic concentrations of specific sets of transcription factors is essential for correct programming of cell proliferation and differentiation. We have characterized the signal transduction pathways regulating the catabolisis of p45/NF-E2, a bZIP factor activating the erythroid and megakaryocytic gene transcription. Through use of different approaches including nano-scale proteomics, we show that activated-JNK, or Phospho-JNK (P-JNK), physically interacts with p45/NF-E2 and phosphorylates its Ser157 residue. This reaction leads to the poly-ubiquitination of p45/NF-E2 at one or more of six Lys residues, one of which being also a sumoylation site, and its degradation through the proteasome pathway. Significantly, this regulatory pathway of p45/NF-E2 by P-JNK exists only in uninduced murine erythroleukemia (MEL) cells but not in differentiated MEL cells in which JNK is inactivated on DMSO induction. Based on the above data and analysis of the chromatin-binding kinetics of p45/NF-E2 and the erythroid gene repressor Bach1 during the early phase of MEL differentiation, we suggest a model for the regulation of erythroid maturation. In the model, the posttranslational modifications and turnover of p45/NF-E2, as mediated by P-JNK, contribute to the control of its homeostatic concentration and consequently, its regulatory functions in the progression of erythroid differentiation and erythroid gene expression.egulation of erythroid differentiation is complex and occurs in multiple steps. Cytokines and nuclear hormones all play important roles in the maturation of erythroid cells. For example, it is known that signaling from the erythropoietin (Epo) receptor activates several pathways to promote cell proliferation, differentiation, and survival (1). Transcription factors such as GATA-1, EKLF, Bach1, and NF-E2 are also crucial for regulation of erythroid differentiation and maturation (2, 3). Among the many systems for studying the molecular mechanisms of erythroid differentiation is MEL (4-6). The MEL cells are derived from murine erythroleukemia by infection of the Friend virus, causing Epo-independent polyclonal expansion through a constitutive activation of the Epo receptor (7). During the early hours after exposure to differentiation-inducing agents such as DMSO or hexamethylene bisacetamide (HMBA), MEL cells undergo alterations that commit them to cessation of growth and to development of the characteristics of differentiation (8, 9).Multiple kinases are involved during MEL differentiation. For example, the inhibition of PI3 kinase reduces the GATA-1 binding to its DNA targets and thus, prevents MEL differentiation. On one hand, the PKC δ, and possibly PKC ε and PKC ζ as well, also plays a role in the HMBA-mediated differentiation of MEL, although their downstream targets are not clear yet (10). On the other hand, the MAPK families including p38, JNK, and ERK have been shown to be essential for Epo-dependent cell growth (11,12). This subfamily of the MAPK, including JNK and p38, could be activate...

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Section: P-jnk-mediated Turnover and Differential Chromatin-binding Osupporting

confidence: 61%

JNK-mediated turnover and stabilization of the transcription factor p45/NF-E2 during differentiation of murine erythroleukemia cells

Lee

Shyu

Hsu

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

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“…745A cells were transfected by electroporation as previously described 17 with either the pSFFVneo plasmid (745A/Neo) or plasmid constructs. Individual cell clones were selected with 300 g/mL geneticin (G418; Gibco-BRL).…”

Section: Cell Lines and Transfectionmentioning

confidence: 99%

Bcl-XL is required for heme synthesis during the chemical induction of erythroid differentiation of murine erythroleukemia cells independently of its antiapoptotic function

Hafid-Medheb

Augery-Bourget

Minatchy

et al. 2003

Blood

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Bcl-XL is essential for the survival and normal maturation of erythroid cells, especially at the late stage of erythroid differentiation. It remains unclear whether Bcl-XL serves only as a survival factor for erythroid cells or if it can induce a signal for differentiation. We have previously shown that dimethyl sulfoxide (DMSO) induction of erythroid differentiation in murine erythroleukemia (MEL) cells correlates with delay of apoptosis and specific induction of Bcl-XL. In this study, we investigate the contribution of Bcl-2 and Bcl-XL to survival and erythroid differentiation by generating stable MEL transfectants expressing these antiapoptotic regulators. Overexpression of Bcl-2 completely prevented apoptosis of MEL cells before and after DMSO induction, whereas overexpression of Bcl-XL only delayed it. Overexpression of Bcl-2 or Bcl-XL neither induced spontaneous erythroid differentiation nor accelerated DMSO-induced differentiation. Inhibition of Bcl-XL by antisense transcripts accelerated apoptosis in DMSO-treated MEL cells and blocked the synthesis of hemoglobin without altering the growth arrest associated with terminal erythroid differentiation. An antisense oligonucleotide to Bcl-XL did not induce apoptosis in MEL cells overexpressing Bcl-2 but greatly decreased their hemoglobin synthesis when treated with DMSO, suggesting that Bcl-XL is necessary for erythroid differentiation independently of its antiapoptotic function. Importantly, Bcl-XL antisense transcripts prevented heme synthesis but not globin mRNA induction in DMSO-treated MEL cells. Furthermore, inhibition of hemoglobin synthesis by Bcl-XLantisense was reversed by addition of exogenous hemin. Finally, Bcl-XL localized to mitochondria during MEL erythroid differentiation, suggesting that it may mediate a critical mitochondrial transport function related to heme biosynthesis.

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“…However, NF-E2 DNA-binding activity and transcriptional activity increase markedly upon induction (14,20). NF-E2p18 is expressed at significantly lower levels than NF-E2p45, and overexpression of NF-E2p18 in uninduced MEL cells leads to an increase in NF-E2 DNA binding activity, increased globin gene expression, and accelerated erythroid differentiation (20,21).…”

mentioning

confidence: 99%

Nuclear relocation of a transactivator subunit precedes target gene activation

Francastel

Magis

Groudine

2001

Proc. Natl. Acad. Sci. U.S.A.

130

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Murine erythroleukemia (MEL) cells are a model system to study reorganization of the eukaryotic nucleus during terminal differentiation. Upon chemical induction, MEL cells undergo erythroid differentiation, leading to activation of globin gene expression. Both processes strongly depend on the transcriptional activator NF-E2. Before induction of differentiation, both subunits of the NF-E2 heterodimer are present, but little DNA-binding activity is detectable. Using immunofluorescence microscopy, we show that the two NF-E2 subunits occupy distinct nuclear compartments in uninduced MEL cells; the smaller subunit NF-E2p18 is found primarily in the centromeric heterochromatin compartment, whereas the larger subunit NF-E2p45 occupies the euchromatin compartment. Concomitant with the commitment period of differentiation that precedes globin gene activation, NF-E2p18, along with other transcriptional repressors, relocates to the euchromatin compartment. Thus, relocation of NF-E2 p18 may be a rate-limiting step in formation of an active NF-E2 complex. To understand the mechanisms of NF-E2 localization, we show that centromeric targeting of NF-E2p18 requires dimerization, but not with an erythroid-specific partner, and that the transactivation domain of NF-E2p45 may be necessary and sufficient to prevent its localization in centromeric heterochromatin. Finally, using fluorescence in situ hybridization, we show that, upon differentiation, the ␤-globin gene loci relocate away from heterochromatin compartments to euchromatin. This relocation correlates with both transcriptional activation of the globin locus and relocation of NF-E2p18 away from heterochromatin, suggesting that these processes are linked.

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NF-E2p18/mafK is required in DMSO-induced differentiation of Friend erythroleukemia cells by enhancing NF-E2 activity

Abstract: encoding heme biosynthetic enzymes, porphobilinogen

Cited by 25 publications

References 4 publications

JNK-mediated turnover and stabilization of the transcription factor p45/NF-E2 during differentiation of murine erythroleukemia cells

JNK-mediated turnover and stabilization of the transcription factor p45/NF-E2 during differentiation of murine erythroleukemia cells

Bcl-XL is required for heme synthesis during the chemical induction of erythroid differentiation of murine erythroleukemia cells independently of its antiapoptotic function

Nuclear relocation of a transactivator subunit precedes target gene activation

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