Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Fusion of the MN1 gene to TEL (ETV6) results in myeloid leukemia. The fusion protein combines the transcription activating domain of MN1 and the DNA binding domain of TEL and is thought to act as a deranged transcription factor. In addition, disruption of the large first exon of the MN1 gene is thought to inactivate MN1 function in a meningioma. To further investigate the role of MN1 in cancer, we generated Mn1 knockout mice. Mn1(+/-) animals were followed for 30 months, but they had no higher incidence of tumor formation than wild-type littermates. Mn1 null mice, however, were found to die at birth or shortly thereafter as the result of a cleft palate. Investigation of newborn or embryonic day 15.5 (E15.5) to E17.5 null mice revealed that the development of several bones in the skull was abnormal. The affected bones are almost exclusively formed by intramembranous ossification. They are either completely agenic at birth (alisphenoid and squamosal bones and vomer), hypoplastic, deformed (basisphenoid, pterygoid, and presphenoid), or substantially thinner (frontal, parietal, and interparietal bones). In heterozygous mice hypoplastic membranous bones and incomplete penetrance of the cleft palate were observed. We conclude that Mn1 is an important factor in development of membranous bones.
Mol Cell Biol 2005 May
PMID:Targeted disruption of the Mn1 oncogene results in severe defects in development of membranous bones of the cranial skeleton. 1587 Feb 92

The p85alpha subunit of phosphatidylinositol 3-kinase (PI-3k) forms a complex with a protein network associated with oncogenic fusion tyrosine kinases (FTKs) such as BCR/ABL, TEL/ABL, TEL/JAK2, TEL/PDGFbetaR, and NPM/ALK, resulting in constitutive activation of the p110 catalytic subunit of PI-3k. Introduction of point mutations in the N-terminal and C-terminal SH2 domain and SH3 domain of p85alpha, which disrupt their ability to bind phosphotyrosine and proline-rich motifs, respectively, abrogated their interaction with the BCR/ABL protein network. The p85alpha mutant protein (p85mut) bearing these mutations was unable to interact with BCR/ABL and other FTKs, while its binding to the p110alpha catalytic subunit of PI-3k was intact. In addition, binding of Shc, c-Cbl, and Gab2, but not Crk-L, to p85mut was abrogated. p85mut diminished BCR/ABL-dependent activation of PI-3k and Akt kinase, the downstream effector of PI-3k. This effect was associated with the inhibition of BCR/ABL-dependent growth of the hematopoietic cell line and murine bone marrow cells. Interestingly, the addition of interleukin-3 (IL-3) rescued BCR/ABL-transformed cells from the inhibitory effect of p85mut. SCID mice injected with BCR/ABL-positive hematopoietic cells expressing p85mut survived longer than the animals inoculated with BCR/ABL-transformed counterparts. In conclusion, we have identified the domains of p85alpha responsible for the interaction with the FTK protein network and transduction of leukemogenic signaling.
Mol Cell Biol 2005 Sep
PMID:Phosphatidylinositol 3-kinase p85{alpha} subunit-dependent interaction with BCR/ABL-related fusion tyrosine kinases: molecular mechanisms and biological consequences. 1613 92

The IGF-binding protein (IGFBP) family consists of six proteins that are expressed and secreted in different tissues. The proteins are regulators of physiological processes throughout the body by modulating the activity of IGF-I and IGF-II. In this article, we describe the coordinated expression of IGFBP5 and MN1 in meningiomas. MN1 is a transcriptional co-activator and we show that MN1 stimulates the IGFBP5 promoter in Hep3B cells. A CACCC-containing sequence, located 140 bp upstream of the transcription start site of the promoter, is required for MN1 action. This sequence matches with the CACCCAC consensus sequence that was selected in an oligonucleotide selection assay performed for MN1. The CACCC element has also been shown to be important for induction of the IGFBP5 promoter by retinoic acid (RA) and progesterone (Pg). We were unable to confirm the effect of Pg on the promoter in Hep3B and U2-osteosarcoma cells regardless of the presence of MN1. On the other hand, we show that induction of the promoter by RA depends on co-expressed MN1 in Hep3B cells. MN1TEL, a leukemia-related fusion protein containing parts of the MN1 and TEL (ETV6) genes, is capable of stimulating the IGFBP5 promoter but is unable to cooperate with RA in Hep3B cells. This suggests that the effects of RA can be negatively affected in leukemias caused by MN1TEL.
J Mol Endocrinol 2007 Feb
PMID:The MN1 oncoprotein activates transcription of the IGFBP5 promoter through a CACCC-rich consensus sequence. 1724 74

The expression of the myeloid markers CD13, CD33, and CD15 in two hundred and eighty-three cases of de novo childhood acute lymphoblastic leukemia (ALL) is examined. The expression of at least one marker is a frequent event which is noted in 64% and 74% of B- and T-lineage ALL cases, respectively. Certain patterns of myeloid antigen expression can be recognized including: no expression of CD13, CD33, and CD15 in mature B-ALL, significantly higher levels of CD13 and CD33 and significantly lower levels of CD15 in TEL-AML1-positive B cell precursor ALL, no expression of CD13 and CD33 in E2A-PBX1-positive B cell precursor ALL cases and common T-ALL (double positive for CD4 and CD8), and no expression of CD13 in MLL-AF4-positive B cell precursor ALL cases. Although the numbers in some ALL subtypes are small, these patterns are consistent with nonrandom expression of myeloid markers in de novo childhood ALL.
Exp Mol Pathol 2007 Aug
PMID:Frequent but nonrandom expression of myeloid markers on de novo childhood acute lymphoblastic leukemia. 1743 63

There are a number of leukemogenic protein-tyrosine kinases (PTKs) associated with leukemic transformation. Although each is linked with a specific disease their functional activity poses the question whether they have a degree of commonality in their effects upon target cells. Exon array analysis of the effects of six leukemogenic PTKs (BCR/ABL, TEL/PDGFRbeta, FIP1/PDGFRalpha, D816V KIT, NPM/ALK, and FLT3ITD) revealed few common effects on the transcriptome. It is apparent, however, that proteome changes are not directly governed by transcriptome changes. Therefore, we assessed and used a new generation of iTRAQ tagging, enabling eight-channel relative quantification discovery proteomics, to analyze the effects of these six leukemogenic PTKs. Again these were found to have disparate effects on the proteome with few common targets. BCR/ABL had the greatest effect on the proteome and had more effects in common with FIP1/PDGFRalpha. The proteomic effects of the four type III receptor kinases were relatively remotely related. The only protein commonly affected was eosinophil-associated ribonuclease 7. Five of six PTKs affected the motility-related proteins CAPG and vimentin, although this did not correspond to changes in motility. However, correlation of the proteomics data with that from the exon microarray not only showed poor levels of correlation between transcript and protein levels but also revealed alternative patterns of regulation of the CAPG protein by different oncogenes, illustrating the utility of such a combined approach.
Mol Cell Proteomics 2008 May
PMID:Eight-channel iTRAQ enables comparison of the activity of six leukemogenic tyrosine kinases. 1795 28

Dysregulation of the receptor tyrosine kinase fibroblast growth factor receptor 3 (FGFR3) plays a pathogenic role in a number of human hematopoietic malignancies and solid tumors. These include t(4;14) multiple myeloma associated with ectopic expression of FGFR3 and t(4;12)(p16;p13) acute myeloid leukemia associated with expression of a constitutively activated fusion tyrosine kinase, TEL-FGFR3. We recently reported that FGFR3 directly tyrosine phosphorylates RSK2 at Y529, which consequently regulates RSK2 activation. Here we identified Y707 as an additional tyrosine in RSK2 that is phosphorylated by FGFR3. Phosphorylation at Y707 contributes to RSK2 activation, through a putative disruption of the autoinhibitory alphaL-helix on the C terminus of RSK2, unlike Y529 phosphorylation, which facilitates ERK binding. Moreover, we found that FGFR3 interacts with RSK2 through residue W332 in the linker region of RSK2 and that this association is required for FGFR3-dependent phosphorylation of RSK2 at Y529 and Y707, as well as the subsequent RSK2 activation. Furthermore, in a murine bone marrow transplant assay, genetic deficiency in RSK2 resulted in a significantly delayed and attenuated myeloproliferative syndrome induced by TEL-FGFR3 as compared with wild-type cells, suggesting a critical role of RSK2 in FGFR3-induced hematopoietic transformation. Our current and previous findings represent a paradigm for tyrosine phosphorylation-dependent regulation of serine-threonine kinases.
Mol Cell Biol 2009 Apr
PMID:Fibroblast growth factor receptor 3 associates with and tyrosine phosphorylates p90 RSK2, leading to RSK2 activation that mediates hematopoietic transformation. 1922 61

Acute lymphoblastic leukemia (ALL) accounts for approximately 80% of all acute leukemias during childhood. Chromosomal anomalies resulting from gene fusion, which are frequent in leukemias, create hybrid transcripts, the great majority of which encode transcription factors. We analyzed 88 pediatric patients (median age 7.3 years) who had B-lineage acute lymphoblastic leukemia (B-ALL), using reverse transcriptase-polymerase chain reaction, to look for gene fusion transcripts of TEL/AML1, E2A/PBX1, BCR/ABL p190, and MLL/AF4. The frequencies of these transcripts were 21.21, 9.68, 3.03, and 0%, respectively. All positive cases had a common B-ALL immunophenotype. The low frequency of the TEL/AML1 transcript that is found in developing countries, such as Brazil, may be due to the low incidence of leukemia; this would support Greaves' hypothesis.
Genet Mol Res 2009 Mar 24
PMID:Molecular and chromosomal mutations among children with B-lineage lymphoblastic leukemia in Brazil's Federal District. 1944 Sep 70

Childhood acute lymphoblastic leukemia (ALL) is caused by malignant immature lymphocytes. Even though childhood ALL can be cured in a large number of patients, around 20% of the patients suffer a relapse after chemotherapy. The origin of the relapse is unclear at the present time. Given the high plasticity of cells, we searched for leukemia-associated genetic aberrations and immunoglobulin (IG) gene rearrangements in mesenchymal stem cells (MSC) from childhood B-cell precursor ALL patients. MSC from all ten ALL patients analyzed presented the chromosomal translocations that had been detected in leukemia cells (TEL-AML1, E2A-PBX1, or MLL rearrangement). The proportions of translocation-positive MSC varied between 10% and 54% depending on the patients and the time point of analysis. Leukemia-specific IG gene rearrangements were detected in the MSC from three ALL patients. The detection of leukemia-associated genetic aberrations in MSC indicates a clonal relationship between MSC and leukemia cells and suggests their involvement in the pathogenesis and/or pathophysiology of childhood ALL.
J Mol Med (Berl) 2010 Mar
PMID:Leukemia-associated genetic aberrations in mesenchymal stem cells of children with acute lymphoblastic leukemia. 2013 87

Signaling pathways and their protein target constituents (e.g. kinases) have become important therapeutic targets in many disease areas. Traditional selectivity profiling for kinase inhibitors has relied upon screening panels of recombinant enzymes in biochemical assay formats. Recent studies have highlighted the importance of using cellular assays to better approximate true biological selectivity. We have developed a portfolio of CellSensor beta-lactamase transcriptional reporter gene assays that can be used to screen for perturbagens of various endogenous signaling pathways. Here we describe a multi-pathway profiling approach for generating compound-pathway selectivity maps. To demonstrate the utility of this approach, we have screened 32 known compounds across a diverse panel of 12 key signaling pathways and generated the first comprehensive cellular pathway selectivity profiles of several clinically approved kinase and other well-known bioactive inhibitors. Selectivity score comparisons identified several kinase inhibitors that were more promiscuous than predicted by traditional biochemical profiling methods. For example, we identified effects of sorafenib on the JAK/STAT pathway and demonstrated the potential therapeutic indication of sorafenib in treating leukemia/myeloproliferative disorder patients harboring TEL-JAK2 or JAK2V617F mutations. Our results indicate that multi-pathway profiling can efficiently characterize both on and off-pathway compound activities, revealing potential novel pathways and opportunities for drug repositioning purposes and/or safety liabilities in one profiling campaign.
Mol Biosyst 2010 Oct
PMID:Multi-pathway cellular analysis of compound selectivity. 2059 73

The expression of genes residing near telomeres is attenuated through telomere position-effect variegation (TPEV). By using a URA3 reporter located at TEL-VII-L of Saccharomyces cerevisiae, it was proposed that the disruptor of telomeric silencing-1 (Dot1) regulates TPEV by catalyzing H3K79 methylation. URA3 reporter assays also indicated that H3K79 methylation is required for HM silencing. Surprisingly, a genome-wide expression analysis of H3K79 methylation-defective mutants identified only a few telomeric genes, such as COS12 at TEL-VII-L, to be subject to H3K79 methylation-dependent natural silencing. Consistently, loss of Dot1 did not globally alter Sir2 or Sir3 occupancy in subtelomeric regions, but only led to some telomere-specific changes. Furthermore, H3K79 methylation by Dot1 did not play a role in the maintenance of natural HML silencing. Therefore, commonly used URA3 reporter assays may not report on natural PEV, and therefore, studies concerning the epigenetic mechanism of silencing in yeast should also employ assays reporting on natural gene expression patterns.
Mol Cell 2011 Apr 08
PMID:Dot1 and histone H3K79 methylation in natural telomeric and HM silencing. 2147 73


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