Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P51532 (transcriptional activator)
 6,546 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Myc family proteins play an important role in cellular processes such as proliferation, differentiation, apoptosis and transformation. A number of interaction partners of Myc have been identified, such as Max, p107, TBP, YY1, Miz-1, AP-2 and Nmi. Both Max and Nmi also bind to MycN. In contrast to the well defined binding of Max to Myc family proteins the interaction of Nmi with Myc or MycN is only poorly characterized. By employing the yeast two-hybrid system we have mapped the regions of MycN and Myc responsible for binding to Nmi. For MycN exclusively a central region mediates binding to Nmi. In contrast, for Myc a C-terminal portion of the protein, and possibly also a central part, is involved in Nmi interaction. Nmi does not interact with Max and has no transactivation capabilities in yeast, suggesting that Nmi alone is not a transcriptional activator in mammalian cells. Immunofluorescence demonstrates that both in 293 embryonic kidney cells and in Kelly neuroblastoma cells all detectable ectopically expressed Nmi is localized in the cytoplasm, in part in a punctate, granular pattern. MycN, which is highly expressed in Kelly cells consequent to amplification, appears to be localized exclusively in the nuclei. This directly demonstrates that in the same cell at least the major proportion of MycN and Nmi is localized in different cellular compartments. This result is confirmed by the finding that endogenous Nmi, which is expressed in Kelly cells only after stimulation with interferon gamma, is detected exclusively in the cytoplasm of these cells. Therefore only a very small amount of MycN and Nmi is likely to be involved in MycN/Nmi interaction in vivo.
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PMID:Nmi protein interacts with regions that differ between MycN and Myc and is localized in the cytoplasm of neuroblastoma cells in contrast to nuclear MycN. 1059 90

The BCL6 proto-oncogene encodes a transcriptional repressor that is required for germinal center formation and has been linked to lymphomagenesis. BCL6 functions by directly binding to specific DNA sequences and suppressing the transcription of target genes. Here we report an alternative mechanism by which BCL6 controls the transcription of genes lacking a BCL6 binding site and show that this mechanism was required for the prevention of tumor suppressor p53-independent cell cycle arrest in germinal center B cells. BCL6 interacted with the transcriptional activator Miz-1 and, via Miz-1, bound to the promoter and suppressed transcription of the cell cycle arrest gene CDKN1A. Through this mechanism, BCL6 may facilitate the proliferative expansion of germinal centers during the normal immune response and, when deregulated, the pathological expansion of B cell lymphomas.
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PMID:BCL6 interacts with the transcription factor Miz-1 to suppress the cyclin-dependent kinase inhibitor p21 and cell cycle arrest in germinal center B cells. 1617 1

Amelogenin (AMELX) is the main component of the developing tooth enamel matrix and is essential for enamel thickness and structure. However, little is known about its transcriptional regulation. Using gene expression analysis, we found that MIZ-1, a potent transcriptional activator of CDKN1A, is expressed during odontoblastic differentiation of hDPSCs (human dental pulp stem cells), and is essential for odontoblast differentiation and mineralization. We also investigated how MIZ-1 regulates gene expression of AMELX. Oligonucleotide-pull down assays showed that MIZ-1 binds to an MRE (MIZ-1 binding element) of the AMELX proximal promoter region (bp, -170 to -25). Combined, our ChIP, transient transcription assays, and promoter mutagenesis revealed that MIZ-1 directly binds to the MRE of the Amelx promoter recruits p300 and induces Amelx gene transcription. Finally, we show that the zinc finger protein MIZ-1 is an essential transcriptional activator of Amelx, which is critical in odontogenesis and matrix mineralization in the developing tooth.
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PMID:Role of MIZ-1 in AMELX gene expression. 2895 74

Acute myeloid leukemia (AML) has poor prognosis due to various mutations, e.g., in the FLT3 gene. Therefore, it is important to identify pathways regulated by the activated Flt3 receptor for the discovery of new therapeutic targets. The Myc network of oncogenes and tumor suppressor genes is involved in mechanisms regulating proliferation and survival of cells, including that of the hematopoietic system. In this study, we evaluated the expression of the Myc oncogenes and Mxd antagonists in hematopoietic stem cell and myeloid progenitor populations in the Flt3-ITD-knockin myeloproliferative mouse model. Our data shows that the expression of Myc network genes is changed in Flt3-ITD mice compared with the wild type. Mycn is increased in multipotent progenitors and in the pre-GM compartment of myeloid progenitors in the ITD mice while the expression of several genes in the tumor suppressor Mxd family, including Mxd1, Mxd2, and Mxd4, is concomitantly downregulated, as well as the expression of the Mxd-related gene Mnt and the transcriptional activator Miz-1. LSKCD150+CD48- hematopoietic long-term stem cells are decreased in the Flt3-ITD cells while multipotent progenitors are increased. Of note, PKC412-mediated inhibition of Flt3-ITD signaling results in downregulation of cMyc and upregulation of the Myc antagonists Mxd1, Mxd2, and Mxd4. Our data provides new mechanistic insights into downstream alterations upon aberrant Flt3 signaling and rationale for combination therapies for tyrosine kinase inhibitors with Myc antagonists in treating AML.
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PMID:The Myc/Max/Mxd Network Is a Target of Mutated Flt3 Signaling in Hematopoietic Stem Cells in Flt3-ITD-Induced Myeloproliferative Disease. 3042 Aug 89