GATA-1 interacts with the myeloid PU.1 transcription factor and represses PU.1-dependent transcription

Blood ◽  
2000 ◽  
Vol 95 (8) ◽  
pp. 2543-2551 ◽  
Author(s):  
Claus Nerlov ◽  
Erich Querfurth ◽  
Holger Kulessa ◽  
Thomas Graf

Abstract The GATA-1 transcription factor is capable of suppressing the myeloid gene expression program when ectopically expressed in myeloid cells. We examined the ability of GATA-1 to repress the expression and function of the PU.1 transcription factor, a central regulator of myeloid differentiation. We found that GATA-1 is capable of suppressing the myeloid phenotype without interfering with PU.1 gene expression, but instead was capable of inhibiting the activity of the PU.1 protein in a dose-dependent manner. This inhibition was independent of the ability of GATA-1 to bind DNA, suggesting that it is mediated by protein-protein interaction. We examined the ability of PU.1 to interact with GATA-1 and found a direct interaction between the PU.1 ETS domain and the C-terminal finger region of GATA-1. Replacing the PU.1 ETS domain with the GAL4 DNA-binding domain removed the ability of GATA-1 to inhibit PU.1 activity, indicating that the PU.1 DNA-binding domain, rather than the transactivation domain, is the target for GATA-1–mediated repression. We therefore propose that GATA-1 represses myeloid gene expression, at least in part, through its ability to directly interact with the PU.1 ETS domain and thereby interfere with PU.1 function.

Blood ◽  
2000 ◽  
Vol 95 (8) ◽  
pp. 2543-2551 ◽  
Author(s):  
Claus Nerlov ◽  
Erich Querfurth ◽  
Holger Kulessa ◽  
Thomas Graf

The GATA-1 transcription factor is capable of suppressing the myeloid gene expression program when ectopically expressed in myeloid cells. We examined the ability of GATA-1 to repress the expression and function of the PU.1 transcription factor, a central regulator of myeloid differentiation. We found that GATA-1 is capable of suppressing the myeloid phenotype without interfering with PU.1 gene expression, but instead was capable of inhibiting the activity of the PU.1 protein in a dose-dependent manner. This inhibition was independent of the ability of GATA-1 to bind DNA, suggesting that it is mediated by protein-protein interaction. We examined the ability of PU.1 to interact with GATA-1 and found a direct interaction between the PU.1 ETS domain and the C-terminal finger region of GATA-1. Replacing the PU.1 ETS domain with the GAL4 DNA-binding domain removed the ability of GATA-1 to inhibit PU.1 activity, indicating that the PU.1 DNA-binding domain, rather than the transactivation domain, is the target for GATA-1–mediated repression. We therefore propose that GATA-1 represses myeloid gene expression, at least in part, through its ability to directly interact with the PU.1 ETS domain and thereby interfere with PU.1 function.


2017 ◽  
Author(s):  
Jungeui Hong ◽  
Nathan Brandt ◽  
Ally Yang ◽  
Tim Hughes ◽  
David Gresham

Understanding the molecular basis of gene expression evolution is a central problem in evolutionary biology. However, connecting changes in gene expression to increased fitness, and identifying the functional basis of those changes, remains challenging. To study adaptive evolution of gene expression in real time, we performed long term experimental evolution (LTEE) of Saccharomyces cerevisiae (budding yeast) in ammonium-limited chemostats. Following several hundred generations of continuous selection we found significant divergence of nitrogen-responsive gene expression in lineages with increased fitness. In multiple independent lineages we found repeated selection for non-synonymous mutations in the zinc finger DNA binding domain of the activating transcription factor (TF), GAT1, that operates within incoherent feedforward loops to control expression of the nitrogen catabolite repression (NCR) regulon. Missense mutations in the DNA binding domain of GAT1 reduce its binding affinity for the GATAA consensus sequence in a promoter-specific manner, resulting in increased expression of ammonium permease genes via both direct and indirect effects, thereby conferring increased fitness. We find that altered transcriptional output of the NCR regulon results in antagonistic pleiotropy in alternate environments and that the DNA binding domain of GAT1 is subject to purifying selection in natural populations. Our study shows that adaptive evolution of gene expression can entail tuning expression output by quantitative changes in TF binding affinities while maintaining the overall topology of a gene regulatory network.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 3403-3403
Author(s):  
Xinyang Zhao ◽  
Ly P. Vu ◽  
Fabiana Perna ◽  
Fan Liu ◽  
Hao Xu ◽  
...  

Abstract Abstract 3403 RUNX1 is a transcription factor that is required for definitive hematopoietic development, and helps regulate long term hematopoietic stem cell self-renewal, platelet production, and lymphocyte development during adult hematopoiesis. RUNX1 is known to be modified via phosphorylation, acetylation, ubiquitination and methylation, for example on R208 and R210 by PRMT1, which activates its activating function. We continue to investigate how the methylation of RUNX1 by other protein arginine methyl transferases (PRMTs) regulates its function. Loop 9 of the DNA binding domain (the Runt domain) of RUNX1 contains an SGRGK sequence that is also present on the tails of histone H2A and H4. The histone tails of H4 and H2A can be methylated by a purified PRMT5 complex in vitro. An enzymatically active in vitro PRMT5 complex capable of methylating histones and SM proteins requires two subunits: both PRMT5 and MEP50, a WD 40 repeat domain protein. Nevertheless, this purified PRMT5/MEP50 complex cannot methylate the DNA binding domain of the RUNX1 protein in vitro. We show that RUNX1 also can be symmetrically methylated at R142 within the SGRGK motif in vitro by a nuclear PRMT5/MEP50 complex which also contains COPR5. We show after RUNX1 is methylated on R142 within the nucleus of HEL cells, RUNX1 is exported to the cytoplasm in a CRM1 dependent manner, as the export of methylated RUNX1 is blocked by lemptomycin B. CRM1 interacts with PRMT5, supporting that PRMT5 mediated arginine methylation tags protein for nuclear export. Therefore, PRMT5 not only involves in epigenetic regulation by methylation of histones but also it can directly controls the level of transcription factor proteins within the nucleus. Polycytocemia Vera patients who express the Jak2V617F mutation have low PRMT5 activity due to JAK2V617F mediated PRMT5 phosphorylation (Liu et al 2011). How Jak2 signaling affects RUNX1 methylation and RUNX1 localization within the nucleus is still under investigation. By controlling the amount of RUNX1 available within the cell nucleus, PRMT5 may regulate lineage differentiation potential and growth potential of hematopoietic stem and progenitor cells. The nuclear localization of RUNX1 can be changed through post translational modification such as arginine methylation in addition to point mutations and translocations involving RUNX1 found patients with leukemia and pre-leukemic diseases. Disclosures: No relevant conflicts of interest to declare.


2009 ◽  
Vol 424 (2) ◽  
pp. 253-261 ◽  
Author(s):  
Yukiko Takemori ◽  
Yasuaki Enoki ◽  
Noritaka Yamamoto ◽  
Yo Fukai ◽  
Kaori Adachi ◽  
...  

HSF (heat-shock transcription factor) trimers bind to the HSE (heat-shock element) regulatory sequence of target genes and regulate gene expression. A typical HSE consists of at least three contiguous inverted repeats of the 5-bp sequence nGAAn. Yeast HSF is able to recognize discontinuous HSEs that contain gaps in the array of the nGAAn sequence; however, hHSF1 (human HSF1) fails to recognize such sites in vitro, in yeast and in HeLa cells. In the present study, we isolated suppressors of the temperature-sensitive growth defect of hHSF1-expressing yeast cells. Intragenic suppressors contained amino acid substitutions in the DNA-binding domain of hHSF1 that enabled hHSF1 to regulate the transcription of genes containing discontinuous HSEs. The substitutions facilitated hHSF1 oligomerization, suggesting that the DNA-binding domain is important for this conformational change. Furthermore, other oligomerization-prone derivatives of hHSF1 were capable of recognizing discontinuous HSEs. These results suggest that modulation of oligomerization is important for the HSE specificity of hHSF1 and imply that hHSF1 possesses the ability to bind to and regulate gene expression via various types of HSEs in diverse cellular processes.


1998 ◽  
Vol 18 (3) ◽  
pp. 1590-1600 ◽  
Author(s):  
Kazushi Inoue ◽  
Charles J. Sherr

ABSTRACT A novel 761-amino-acid transcription factor, DMP1, contains a central DNA binding domain that includes three imperfect myb repeats flanked by acidic transactivating domains at the amino and carboxyl termini. D-type cyclins associate with a region of the DMP1 DNA binding domain immediately adjacent to the myb repeats to form heteromeric complexes which detectably interact neither with cyclin-dependent kinase 4 (CDK4) nor with DNA. The segment of D-type cyclins required for its interaction with DMP1 falls outside the “cyclin box,” which contains the residues predicted to contact CDK4. Hence, D-type cyclin point mutants that do not interact with CDK4 can still bind to DMP1. Enforced coexpression of either of three D-type cyclins (D1, D2, or D3) with DMP1 in mammalian cells canceled its ability to activate gene expression. This property was not shared by cyclins A, B, C, or H; did not depend upon CDK4 or CDK2 coexpression; was not subverted by a mutation in cyclin D1 that prevents its interaction with CDK4; and was unaffected by inhibitors of CDK4 catalytic activity. Introduction of DMP1 into mouse NIH 3T3 fibroblasts inhibited entry into S phase. Cell cycle arrest depended upon the ability of DMP1 to bind to DNA and to transactivate gene expression and was specifically antagonized by coexpression of D-type cyclins, including a D1 point mutant that does not bind to CDK4. Taken together, these findings suggest that DMP1 induces genes that inhibit S phase entry and that D-type cyclins can override DMP1-mediated growth arrest in a CDK-independent manner.


Biochemistry ◽  
2004 ◽  
Vol 43 (51) ◽  
pp. 16027-16035 ◽  
Author(s):  
Shinichiro Oka ◽  
Yasuhisa Shiraishi ◽  
Takuya Yoshida ◽  
Tadayasu Ohkubo ◽  
Yukio Sugiura ◽  
...  

1996 ◽  
Vol 236 (3) ◽  
pp. 911-921 ◽  
Author(s):  
Jurgen Schultheiss ◽  
Olaf Kunert ◽  
Uwe Gase ◽  
Klaus-Dieter Scharf ◽  
Lutz Nover ◽  
...  

2003 ◽  
Vol 17 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Raj Kumar ◽  
E. Brad Thompson

Abstract The N-terminal domains (NTDs) of many members of the nuclear hormone receptor (NHR) family contain potent transcription-activating functions (AFs). Knowledge of the mechanisms of action of the NTD AFs has lagged, compared with that concerning other important domains of the NHRs. In part, this is because the NTD AFs appear to be unfolded when expressed as recombinant proteins. Recent studies have begun to shed light on the structure and function of the NTD AFs. Recombinant NTD AFs can be made to fold by application of certain osmolytes or when expressed in conjunction with a DNA-binding domain by binding that DNA-binding domain to a DNA response element. The sequence of the DNA binding site may affect the functional state of the AFs domain. If properly folded, NTD AFs can bind certain cofactors and primary transcription factors. Through these, and/or by direct interactions, the NTD AFs may interact with the AF2 domain in the ligand binding, carboxy-terminal portion of the NHRs. We propose models for the folding of the NTD AFs and their protein-protein interactions.


Sign in / Sign up

Export Citation Format

Share Document