Inhibition of CBP-Mediated Protein Acetylation by the Ets Family Oncoprotein PU.1

Wang, Hong; Kim, Alexander Y.; Ky, Sokun; Rakowski, Carrie; Seo, Sang-Beom; Chakravarti, Debabrata; Atchison, Michael L.; Blobel, Gerd A.

doi:10.1128/mcb.22.11.3729-3743.2002

Cited by 63 publications

(70 citation statements)

References 90 publications

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“…Consistent with the second model, CBP directly acetylates the GATA1 protein, which increases its transcriptional activity (31,32). In addition, a recent study suggested that the Pu.1 protein blocks erythroid differentiation by blocking the CBP-HAT-catalyzed acetylation of GATA1 and other proteins (33).…”

supporting

confidence: 49%

HOXB6 Protein Is Bound to CREB-binding Protein and Represses Globin Expression in a DNA Binding-dependent, PBX Interaction-independent Process

Shen

Chrobak

Krishnan

et al. 2004

Journal of Biological Chemistry

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Although HOXB6 and other HOX genes have previously been associated with hematopoiesis and leukemias, the precise mechanism of action of their protein products remains unclear. Here we use a biological model in which HOXB6 represses ␣-and ␥-globin mRNA levels to perform a structure/function analysis for this homeodomain protein. HOXB6 protein represses globin transcript levels in stably transfected K562 cells in a DNA-binding dependent fashion. However, the capacity to form cooperative DNA-binding complexes with the PBX co-factor protein is not required for HOXB6 biological activity. Neither the conserved extreme N-terminal region, a polyglutamic acid region at the protein C terminus, nor the Ser 214 CKII phosphorylation site was required for DNA binding or activity in this model. We have previously reported that HOX proteins can inhibit CREB-binding protein (CBP)-histone acetyltransferasemediated potentiation of reporter gene transcription. We now show that endogenous CBP is co-precipitated with exogenous HOXB6 from nuclear and cytoplasmic compartments of transfected K562 cells. Furthermore, endogenous CBP co-precipitates with endogenous HOXB6 in day 14.5 murine fetal liver cells during active globin gene expression in this tissue. The CBP interaction motif was localized to the homeodomain but does not require the highly conserved helix 3. Our data suggest that the homeodomain contains most or all of the important structures required for HOXB6 activity in blood cells.The HOX homeodomain (HD) 1 proteins function as master regulators of the body plan (1). In addition, HOX genes are expressed in blood cells in lineage-specific patterns (2, 3), and HOX proteins are important in the growth and differentiation of normal bone marrow cells and in leukemias (4). We cloned two alternatively spliced HOXB6 cDNAs from HEL cells, a human leukemic cell line with erythroid/myeloid bipotential differentiation capacity (3, 5). In a previous study, enforced expression of one of these cDNAs that encoded a 224-amino acid, HD-containing HOXB6 protein repressed the erythroid phenotype in human leukemic cells, as reflected by the loss of ␣-, ␤-, and ␥-globin gene expression; loss of erythroid surface markers; and down-regulation of heme synthesis (6). However, it has proven difficult to describe a precise biochemical mechanism of action to account for these effects. Similarly, despite genetic studies showing that HOX genes influence the expression of downstream targets, the efforts of numerous investigators have yielded few mechanistic details to explain the action of HOX proteins.Although they are thought to function as transcription factors, most full-length HOX proteins, including HOXB6, bind only weakly by themselves to DNA targets containing a TAAT sequence (7-9). Several laboratories demonstrated that HOX proteins exhibited weak activation or repression on reporter genes containing either TAAT multimers (reviewed in Ref. 10) or HOX gene auto-regulatory elements containing TAAT sequences (11, 12). However, in our own studies, HO...

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supporting

confidence: 49%

HOXB6 Protein Is Bound to CREB-binding Protein and Represses Globin Expression in a DNA Binding-dependent, PBX Interaction-independent Process

Shen

Chrobak

Krishnan

et al. 2004

Journal of Biological Chemistry

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“…(GATA) inhibits the function of GATA (PU.1), resulting in dominion by itself, during the development from hematopoietic stem cells toward the monocyte (erythrocyte/megakaryocyte) lineage (21)(22)(23)(24)(25)(26)(27)(28). In contrast, PU.1 and GATA1/GATA2 exhibit a cooperative function in mast cells, as follows: 1) PU.1 and GATA2 cooperatively induce mast cell development (20); 2) PU.1 and GATA1 synergistically transactivate cell type-specific gene regulation in mast cells (5,29); and 3) PU.1 is required for GATA1 expression in mast cells (30).…”

Section: Discussionmentioning

confidence: 99%

Critical Roles for PU.1, GATA1, and GATA2 in the Expression of Human FcεRI on Mast Cells: PU.1 and GATA1 Transactivate FCER1A, and GATA2 Transactivates FCER1A and MS4A2

Inage

Kasakura

Yashiro

et al. 2014

The Journal of Immunology

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The high-affinity IgE receptor, FcεRI, which is composed of α-, β-, and γ-chains, plays an important role in IgE-mediated allergic responses. In the current study, involvement of the transcription factors, PU.1, GATA1, and GATA2, in the expression of FcεRI on human mast cells was investigated. Transfection of small interfering RNAs (siRNAs) against PU.1, GATA1, and GATA2 into the human mast cell line, LAD2, caused significant downregulation of cell surface expression of FcεRI. Quantification of the mRNA levels revealed that PU.1, GATA1, and GATA2 siRNAs suppressed the α transcript, whereas the amount of β mRNA was reduced in only GATA2 siRNA transfectants. In contrast, γ mRNA levels were not affected by any of the knockdowns. Chromatin immunoprecipitation assay showed that significant amounts of PU.1, GATA1, and GATA2 bind to the promoter region of FCER1A (encoding FcεRIα) and that GATA2 binds to the promoter of MS4A2 (encoding FcεRIβ). Luciferase assay and EMSA showed that GATA2 transactivates the MS4A2 promoter via direct binding. These knockdowns of transcription factors also suppressed the IgE-mediated degranulation activity of LAD2. Similarly, all three knockdowns suppressed FcεRI expression in primary mast cells, especially PU.1 siRNA and GATA2 siRNA, which target FcεRIα and FcεRIβ, respectively. From these results, we conclude that PU.1 and GATA1 are involved in FcεRIα transcription through recruitment to its promoter, whereas GATA2 positively regulates FcεRIβ transcription. Suppression of these transcription factors leads to downregulation of FcεRI expression and IgE-mediated degranulation activity. Our findings will contribute to the development of new therapeutic approaches for FcεRI-mediated allergic diseases.

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“…Spi-1/PU.1 and the major erythroid transcription factor GATA-1 cross antagonize one another through direct interaction (Rekhtman et al, 1999;Zhang et al, 1999Zhang et al, , 2000Nerlov et al, 2000). On the other hand, Spi-1/PU.1 inhibits CBP-mediated acetylation of erythroid transcription factors GATA-1, EKLF and NF-E2 (Hong et al, 2002). Both inhibitory effects of Spi-1/PU.1 are thought to contribute to erythroid differentiation arrest and to malignant transformation.…”

Section: Splicing Of Exon 16 In Differentiating Mel Cells Is Regulatementioning

confidence: 99%

Spi-1/PU.1 but not Fli-1 inhibits erythroid-specific alternative splicing of 4.1R pre-mRNA in murine erythroleukemia cells

Théoleyre

Deguillien²,

Morinière³

et al. 2003

Oncogene

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The inclusion of exon 16 in mature protein 4.1R mRNA arises from a stage-specific splicing event that occurs during late erythroid development. We have shown that mouse erythroleukemia (MEL) cells reproduce this erythroid-specific splicing event upon induction of differentiation. We here found that this splicing event is regulated specifically in erythroleukemic cells that have the potential to differentiate and produce hemoglobin, regardless of the nature of the differentiation inducer. Knowing that dysregulated expression of spi-1/pu.1 and fli-1 oncogenes is involved in MEL cell differentiation arrest, we looked at their effect on exon 16 erythroid splicing. We found that exon 16 inclusion requires Spi-1/ PU.1 shutdown in MEL cells, and that enforced expression of Spi-1/PU.1 inhibits exon selection, regardless of the presence or absence of a chemical inducer. By contrast, endogenous overexpression or enforced expression of Fli-1 has no effect on exon selection. We further showed that Spi-1/PU.1 acts similarly on the endogenous and on a transfected exon 16, suggesting a promoterindependent effect of Spi-1/PU.1 on splicing regulation. This study provides the first evidence that Spi-1/PU.1 displays the unique property, not shared with Fli-1, to inhibit erythroid-specific pre-mRNA splicing in erythroleukemia cell context.

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Inhibition of CBP-Mediated Protein Acetylation by the Ets Family Oncoprotein PU.1

Cited by 63 publications

References 90 publications

HOXB6 Protein Is Bound to CREB-binding Protein and Represses Globin Expression in a DNA Binding-dependent, PBX Interaction-independent Process

HOXB6 Protein Is Bound to CREB-binding Protein and Represses Globin Expression in a DNA Binding-dependent, PBX Interaction-independent Process

Critical Roles for PU.1, GATA1, and GATA2 in the Expression of Human FcεRI on Mast Cells: PU.1 and GATA1 Transactivate FCER1A, and GATA2 Transactivates FCER1A and MS4A2

Spi-1/PU.1 but not Fli-1 inhibits erythroid-specific alternative splicing of 4.1R pre-mRNA in murine erythroleukemia cells

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