Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P15088 (mast cell)
 14,925 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The SCL gene, also known as tal-1, encodes a basic helix-loop-helix transcription factor that is pivotal for the normal development of all hematopoietic lineages. SCL is expressed in committed erythroid, mast, and megakaryocytic cells as well as in hematopoietic stem cells. Nothing is known about the regulation of SCL transcription in mast cells, and in other lineages GATA-1 is the only tissue-specific transcription factor recognized to regulate the SCL gene. We have therefore analyzed the molecular mechanisms underlying SCL expression in mast cells. In this paper, we demonstrate that SCL promoter 1a was regulated by GATA-1 together with Sp1 and Sp3 in a manner similar to the situation in erythroid cells. However, SCL promoter 1b was strongly active in mast cells, in marked contrast to the situation in erythroid cells. Full activity of promoter 1b was dependent on ETS and Sp1/3 motifs. Transcription factors PU.1, Elf-1, Sp1, and Sp3 were all present in mast cell extracts, bound to promoter 1b and transactivated promoter 1b reporter constructs. These data provide the first evidence that the SCL gene is a direct target for PU.1, Elf-1, and Sp3.
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PMID:Transcriptional regulation of the stem cell leukemia gene by PU.1 and Elf-1. 978 9

Interleukin-10 (IL-10) and transforming growth factor beta (TGF-beta) are inhibitory for B and T cells, IgE production, and mast cell proliferation, and they induce apoptosis in eosinophils. These cytokines are therefore candidate genes which could contribute to the development of asthma or allergies. We investigated the hypothesis that polymorphic nucleotides within the IL-10 and TGF-beta gene promoters would link to the expression of allergies and asthma. DNA taken from families with an asthmatic proband was examined for base exchanges by single-stranded conformational polymorphism (SSCP). We demonstrated the presence of a polymorphism in the promoter region of the IL-10 gene and four in the TGF-beta gene promoters (3 in TGF-beta1 and 1 in TGF-beta2). The IL-10 gene polymorphism was a C-to-A exchange 571 base pairs upstream from the translation start site and was present between consensus binding sequences for Sp1 and elevated total serum. This polymorphism was associated with elevated total serum IgE in subjects heterozygotic or homozygotic for this base exchange (p < 0.009). The base exchange at -509 (from the transcription initiation site) in the TGF-beta promoter also linked to elevated total IgE (p < 0.01). This polymorphism represented a C-to-T base exchange which induced a YY1 consensus sequence and is present in a region of the promoter associated with negative transcription regulation.
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PMID:Interleukin-10 and transforming growth factor-beta promoter polymorphisms in allergies and asthma. 984 92

The c-kit gene is expressed in hematopoietic stem cells and lineage progenitor cells but is downregulated during cell development in most lineages, except for mast cells. In mast cells, high expression of c-kit is maintained during development, and c-Kit signaling is essential for mast cell development. To analyze the mechanisms by which c-kit gene expression are regulated in mast cells, we examined mast cell type-specific regulation of the c-kit promoter region. We observed that a GC-box in the c-kit promoter was critical for transcriptional activity and was bound to the transcription factor Sp1 as assessed using reporter assay and electrophoretic mobility assay. Chromatin immunoprecipitation assay and coexpression analyses showed that the transcription factor GATA2, which was recruited to the c-kit promoter in a mast cell-specific manner, in addition to Sp1, transactivated the c-kit promoter via the GC-box. Electrophoretic mobility assay and rechromatin immunoprecipitation assay indicated that GATA2 binds to the GC-box by forming a complex with Sp1. Introduction of Sp1 small interfering RNA significantly reduced the amount not only of Sp1 but also of GATA2 binding to the c-kit promoter in mast cells, resulting in suppression of c-kit transcription. Knockdown of GATA2 suppressed the recruitment of GATA2 toward the c-kit promoter, subsequently suppressing cell surface expression of c-Kit. These findings indicate that GATA2 and Sp1 play crucial roles in expression of the c-kit gene in mast cells.
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PMID:GATA2 and Sp1 positively regulate the c-kit promoter in mast cells. 2083 40

Airway mucin secretion and MC (mast cell) degranulation must be tightly controlled for homoeostasis of the lungs and immune system respectively. We found the exocytic protein Munc18b to be highly expressed in mouse airway epithelial cells and MCs, and localized to the apical pole of airway secretory cells. To address its functions, we created a mouse with a severely hypomorphic Munc18b allele such that protein expression in heterozygotes was reduced by ~50%. Homozygous mutant mice were not viable, but heterozygotes showed a ~50% reduction in stimulated release of mucin from epithelial cells and granule contents from MCs. The defect in MCs affected only regulated secretion and not constitutive or transporter-mediated secretion. The severity of passive cutaneous anaphylaxis was also reduced by ~50%, showing that reduction of Munc18b expression results in an attenuation of physiological responses dependent on MC degranulation. The Munc18b promoter is controlled by INR (initiator), Sp1 (specificity protein 1), Ets, CRE (cAMP-response element), GRE (glucocorticoid-response element), GATA and E-box elements in airway epithelial cells; however, protein levels did not change during mucous metaplasia induced by allergic inflammation. Taken together, the results of the present study identify Munc18b as an essential gene that is a limiting component of the exocytic machinery of epithelial cells and MCs.
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PMID:Munc18b is an essential gene in mice whose expression is limiting for secretion by airway epithelial and mast cells. 2269 44

Cutaneous and subcutaneous mast cell tumours (MCTs) are counted among the most frequent cancers in dogs. However, the genetic aetiology of their development is still mostly unknown, with the exception of KIT and tumor protein p53 (TP53 ) mutations reported in less than a half of cutaneous MCTs. In subcutaneous MCTs, no gene alterations were previously detected. We analysed KIT and TP53 mutations in cutaneous and subcutaneous MCTs, and identified methylated CpG sites in KIT and TP53 promoters and adjacent exon 1 regions. The mutation analysis focused on KIT exons 8, 9 and 11, and TP53 exons 5-8, and revealed mutations in 26% and 7% cutaneous MCT cases, respectively. Moreover, we report a first case of KIT mutation ever detected in subcutaneous MCTs. KIT exon 11 mutations and high Kiupel and Patnaik grades were associated with reduced survival in this study. Both KIT and TP53 gene were generally unmethylated in canine cutaneous MCTs. A sporadic methylation of the CpG positions in KIT promoter and adjacent exon 1 was detected in 70.4% of cutaneous and 82% of subcutaneous MCTs. A sporadic methylation of the CpG positions in the TP53 promoter and exon 1 was observed in 36.8% of the analysed cutaneous MCT samples. Only in two subcutaneous MCTs, we observed more than 30% of clones showing KIT methylation at the CpG positions 13 or 14. The CpG position 14 is involved in a predicted binding site for Sp1 transcription factor. However, the significance of KIT promoter methylation at this specific position needs further evaluation.
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PMID:Mutation and methylation status of KIT and TP53 in canine cutaneous and subcutaneous mast cell tumours. 3157 75