检索结果-内蒙古大学图书馆

p300 mediates transcriptional stimulation by the basic helix-loop-helix activators of the insulin gene

MOLECULAR AND CELLULAR BIOLOGY 1998年第5期18卷 2957-2964页

作者： Qiu, Y Sharma, A Stein, R Vanderbilt Univ Med Ctr Dept Mol Physiol & Biophys Nashville TN 37232 USA Vanderbilt Univ Med Ctr Dept Cell Biol Nashville TN 37232 USA

Pancreatic beta-cell type-specific and glucose-inducible transcription of the insulin gene is mediated by the basic helix-loop-helix factors that bind to and activate expression from an E-box element within its enhancer. The E-box activator is a heteromeric complex composed of a beta-cell enriched factor, BETA2/NeuroD, and ubiquitously distributed proteins encoded by the E2A and HEB genes. Previously, we demonstrated that the adenovirus type 5 E1A proteins repressed stimulation by the E-box activator in beta cells. In this study, our objective was to determine how E1A repressed activator function. The results indicate that E1A reduces activation by binding to and sequestering the p300 cellular coactivator protein. Thus, we show that expression of p300 in beta cells can relieve inhibition by E1A, as well as potentiate activation by the endogenous insulin E-box transcription factors, p300 stimulated activation from GAL4 (amino acids 1 to 147) fusion constructs of either BETA2/NeuroD or the E2A-encoded E47 protein. The sequences spanning the activation domains of BETA2/NeuroD (amino acids 156 to 355) and E47 (amino acids 1 to 99 and 325 to 432) were required for this response. The same region of BETA2/NeuroD was shown to be important for binding to p300 in vitro. The sequences of p300 involved in E47 and BETA2/NeuroD association resided between amino acids 1 and 1257 and 1945 and 2377, respectively. A mutation in p300 that abolished binding to BETA2/NeuroD also destroyed the ability of p300 to activate insulin E-box-directed transcription in beta cells. Our results indicate that physical and functional interactions between p300 and the E-box activator factors play an important role in insulin gene transcription.

关键词： .Mediates basic helix-loop-helix activators insulin gene BETA NeuroD

来源：评论

学校读者我要写书评

暂无评论

Id2 promotes apoptosis by a novel mechanism independent of dimerization to basic helix-loop-helix factors

引用

MOLECULAR AND CELLULAR BIOLOGY 1998年第9期18卷 5435-5444页

作者： Florio, M Hernandez, MC Yang, H Shu, HK Cleveland, JL Israel, MA Univ Calif San Francisco Dept Neurosurg Brain Tumor Res Ctr Preuss Lab Mol Neurooncol San Francisco CA 94143 USA St Jude Childrens Res Hosp Dept Biochem Memphis TN 38105 USA Univ Tennessee Dept Biochem Memphis TN 38163 USA

Members of the helix-loop-helix (HLH) family of Id proteins have demonstrated roles in the regulation of differentiation and cell proliferation. Id proteins inhibit differentiation by HLH-mediated heterodimerization with basic HLH transcription factors. This blocks their sequence-specific binding to DNA and activation of target genes that are often expressed in a tissue-specific manner. Id proteins can also act as positive regulators of cell proliferation. The different mechanisms proposed for Id-mediated promotion of entry into S phase also involve HLH-mediated interactions affecting regulators of the G(1)/S transition. We have found that Id2 augments apoptosis in both interleukin3 (IL-3)-dependent 32D.3 myeloid progenitors and U2OS osteosarcoma cells. We could not detect a similar activity for Id3. In contrast to the effects of Id2 on differentiation and cell proliferation, Id2-mediated apoptosis is independent of HLH-mediated dimerization. The ability of Id2 to promote cell death resides in its N-terminal region and is associated with the enhanced expression of a known component of the programmed cell death pathway, the proapoptotic gene BAX.

关键词： .terminal transcription factors programmed cell progenitors cell proliferation target genes proapoptotic Cell Death brain tumor dimerization regulators basic helix-loop-helix Id proteins Id Promotes HLH-mediated dependent myeloid OS osteosarcoma effects of Id

来源：评论

学校读者我要写书评

暂无评论

Characterization of ABF-1, a novel basic helix-loop-helix transcription factor expressed in activated B lymphocytes

引用

MOLECULAR AND CELLULAR BIOLOGY 1998年第6期18卷 3130-3139页

作者： Massari, ME Rivera, RR Voland, JR Quong, MW Breit, TM van Dongen, JJM de Smit, O Murre, C Univ Calif San Diego Dept Biol La Jolla CA 92093 USA Erasmus Univ Univ Hosp Dijkzigt Dept Immunol Rotterdam Netherlands

Proteins of the basic helix-loop-helix (bHLH) family are required for a number of different developmental pathways, including neurogenesis, lymphopoiesis, myogenesis, and sex determination. Using a yeast two-hybrid screen, we have identified a new bHLH transcription factor, ABF-1, from a human B-cell cDNA library. Within the bHLH region, ABF-1 shows a remarkable conservation with other HLH proteins, including tal-1, NeuroD, and paraxis. Its expression pattern is restricted to a subset of lymphoid tissues, Epstein-Barr virus (EBV)-transformed lymphoblastoid cell lines, and activated human B cells. ABF-1 is capable of binding an E-box element either as a homodimer or as a heterodimer with E2A. Furthermore, a heterodimeric complex containing ABF-1 and E2A can be detected in EBV-immortalized lymphoblastoid cell lines. ABF-1 contains a transcriptional repression domain and is capable of inhibiting the transactivation capability of E47 in mammalian cells. ABF-1 represents the first example of a B-cell-restricted bHLH protein, and its expression pattern suggests that ABF-1 may play a role in regulating antigen-dependent B-cell differentiation.

关键词： .human cells bHLH basic helix-loop-helix two-hybrid

来源：评论

学校读者我要写书评

暂无评论

musculin:: a murine basic helix-loop-helix transcription factor gene expressed in embryonic skeletal muscle

引用

MECHANISMS OF DEVELOPMENT 1998年第1-2期76卷 197-201页

作者： Robb, L Hartley, L Wang, CC Harvey, RP Begley, CG Royal Melbourne Hosp Walter & Eliza Hall Inst Med Res Melbourne Vic 3050 Australia Royal Melbourne Hosp CRC Cellular Growth Factors Melbourne Vic 3050 Australia St Vincents Hosp Victor Chang Cardiac Res Inst Darlinghurst NSW 2010 Australia Univ New S Wales Kensington NSW 2010 Australia

We describe the embryonic expression of musclin, a new murine member of the bHLH family of transcription factors. Musculin protein is closely related to human ABF-1. which is expressed in activated B cells, and to epicardin/capsulin/Pod-1, which is expressed in branchial myoblasts. visceral and urogenital mesoderm and epicardium. In situ hyhridisation revealed musculin expression in embryos was largely restricted to the embryonic skeletal muscle lineage. While all skeletal muscles expressed the gene, only a subset of myocytes within each muscle were positive, indicating molecular heterogeneity within fetal muscle. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.

关键词： ABF-1 basic helix-loop-helix capsulin epicardin musculin myogenic regulatory factor myogenesis Pod-1

来源：评论

学校读者我要写书评

暂无评论

Mist1 expression is a common link among serous exocrine cells exhibiting regulated exocytosis

引用

ANATOMICAL RECORD 2000年第2期259卷 157-167页

作者： Pin, CL Bonvissuto, AC Konieczny, SF Purdue Univ Dept Biol Sci W Lafayette IN 47907 USA

Mist1 is a basic helix-loop-helix transcription factor that represses E-box-mediated transcription. Previous studies have suggested that the Mist1 gene is expressed in a wide range of tissues, although a complete characterization of Mist1 protein accumulation in the adult organism has not been described. In an effort to identify specific cell types that contain the Mist1 protein, antibodies specific for Mist1 were generated and used in Western blot and immunohistochemical assays. Our studies show that the Mist1 protein is present in many different tissues but that it is restricted to cell types that are exclusively secretory in nature. Pancreatic acinar cells, serous or seromucous cells of the salivary glands, chief cells of the stomach, and secretory cells of the prostate and seminal vesicle show high levels of Mist1 protein, whereas nonserous exocrine cells, including the mucus-producing cells of the salivary glands, remain Mist1 negative. These results identify Mist1 as the first transcription factor that exhibits this unique serous-specific expression pattern and suggest that Mist1 may have a key role in establishing and maintaining a pathway responsible for the exocytosis of serous secretions. Anat Rec 259:157-167, 2000. (C) 2000 Wiley-Liss, Inc.

关键词： basic helix-loop-helix E-box transcription acinar cells secretion

来源：评论

学校读者我要写书评

暂无评论

The genomic structure and promoter analysis of the human ABF-1 gene

引用

BIOCHIMICA ET BIOPHYSICA ACTA-GENE STRUCTURE AND EXPRESSION 2000年第2-3期1492卷 320-329页

作者： Mitchell, B Mugiya, M Miller, R Ezpeleta, J Rigby, N Vierra, C Univ Pacific Dept Biol Stockton CA 95211 USA Calif State Univ Stanislaus Dept Biol Turlock CA 95382 USA

The human ABF-1 gene is expressed in activated B-cells and Epstein-Barr virus-immortalized lymphoblastoid cell lines. ABF-1 represents the only member belonging to the basic helix-loop-helix (bHLH) family of transcription factors whose expression pattern is restricted to B-cells. ABF-1 forms heterodimeric complexes with E2A to modulate gene transcription. We report the cloning and characterization of the human ABF-1 gene and the promoter region. The gene spans more than 3 kb and contains two exons. Exon 1 contains 274 bp of a 5'-untranslated sequence (UTR) while exon 2 contains 1097 bp of 3'-UTR. Promoter analysis of the 5'-flanking region revealed no apparent B-cell-restricted control elements within similar to 700 bp, but clearly demonstrated the presence of a functional minimal promoter residing immediately upstream of the transcription start site. Analysis of the region containing the minimal promoter activity identified no CCAAT or TATA sequence. Lastly, we have assigned the ABF-1 gene to human chromosome 8q21.1 using fluorescence in situ hybridization (FISH). The cloning of the human ABF-1 gene will facilitate further biochemical and genetic studies of its function in the regulation of B-cell differentiation. (C) 2000 Elsevier Science B.V. All rights reserved.

关键词： basic helix-loop-helix transcription genomic structure activated B-cell factor promoter DNA-binding protein

来源：评论

学校读者我要写书评

暂无评论

Analysis of HeyL expression in wild-type and Notch pathway mutant mouse embryos

引用

MECHANISMS OF DEVELOPMENT 2000年第1-2期98卷 175-178页

作者： Leimeister, C Schumacher, N Steidl, C Gessler, M Univ Wuerzburg Bioctr Theodor Boveri Inst Inst Physiol Chem 1 D-97074 Wuerzburg Germany

In vertebrates Notch signaling regulates cell fate decisions and boundary formation and it underlies several murine and human diseases. Gene targeting experiments point to key roles of Notch receptors. ligands, modulators and downstream targets in somitogenesis, neurogenesis and vascular development. Here we report the embryonic expression of the hairy-related basic helix-loop-helix gene HeyL in wild-type and Notch pathway mutant mice. We show that HeyL is strongly expressed in the presomitic mesoderm, the somites, the peripheral nervous system and smooth muscle of all arteries. Loss of HeyL expression at the level of nascent somites in Notch1 and Delta-like1 knockout mutants implicates HeyL as a Notch effector during somite formation. Furthermore, HeyL expression in vascular smooth muscle cells and in the thymus strikingly overlaps with that of Notch3, mutations of which underlie the CADASIL vascular disorder. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.

关键词： Hey basic helix-loop-helix hairy Notch Delta somitogenesis somites presomititic mesoderm spinal ganglia cranial ganglia mouse smooth muscles arteries vasculature thymus CADASIL

来源：评论

学校读者我要写书评

暂无评论

The basic domain of myogenic basic helix-loop-helix (bHLH) proteins is the novel target for direct inhibition by another bHLH protein, Twist

引用

MOLECULAR AND CELLULAR BIOLOGY 1997年第11期17卷 6563-6573页

作者： Hamamori, Y Wu, HY Sartorelli, V Kedes, L UNIV SO CALIF HMR413 INST MED GENET SCH MED LOS ANGELES CA 90033 USA UNIV SO CALIF SCH MED DEPT BIOCHEM & MOL BIOL LOS ANGELES CA 90033 USA UNIV BRESCIA SCH MED INST CHEM BRESCIA ITALY

In vertebrates, the basic helix-loop-helix (bHLH) protein Twist may be involved in the negative regulation of cellular determination and in the differentiation of several lineages, including myogenesis, osteogenesis, and neurogenesis. Although it has been shown that mouse twist (M-Twist) (i) sequesters E proteins, thus preventing formation of myogenic E protein-MyoD complexes and (ii) inhibits the MEF2 transcription factor, a cofactor of myogenic bHLH proteins, overexpression of E proteins and MEF2 failed to rescue the inhibitory effects of M-Twist on MyoD. We report here that M-Twist physically interacts with the myogenic bHLH proteins in vitro and in vivo and that this interaction is required for the inhibition of MyoD by M-Twist. In contrast to the conventional HLH-HLH domain interaction formed in the MyoD/E12 heterodimer, this novel type of interaction uses the basic domains of the two proteins. While the MyoD HLH domain without the basic domain failed to interact with M-Twist, a MyoD peptide containing only the basic and helix 1 regions was sufficient to interact with M-Twist, suggesting that the basic domain contacts M-Twist. The replacement of three arginine residues by alanines in the M-Twist basic domain was sufficient to abolish both the binding and inhibition of MyoD by M-Twist, while the domain retained other M-Twist functions such as heterodimerization with an E protein and inhibition of MEF2 transactivation. These findings demonstrate that M-Tvvist interacts with MyoD through the basic domains, thereby inhibiting MyoD.

关键词： .interacts inhibits MEF myogenesis bHLH proteins failed basic helix-loop-helix myogenic bHLH bHLH Protein Twist cellular determination twist Twist inhibition of MyoD basic domains

来源：评论

学校读者我要写书评

暂无评论

Regulation of NeuroD expression by activation of the protein kinase-C pathway in Y79 human retinoblastoma cells

引用

NEUROSCIENCE LETTERS 1999年第1期272卷 45-48页

作者： Noma, T Yoon, YS Yamashiro, Y Fujisawa, K Nakazawa, A Yamaguchi Univ Sch Med Dept Biochem Yamaguchi 7558505 Japan Yamaguchi Univ Sch Med Dept Neurosurg Yamaguchi 7558505 Japan

To examine the signals that regulate NeuroD expression, we analyzed the effects of activation of two major signal pathways, the protein kinase A (PKA) pathway and the protein kinase C (PKC) pathway, on the expression of NeuroD in Y79human retinoblastoma cells. Activation of PKC resulted in marked induction of NeuroD mRNA and NeuroD protein. NeuroD mRNA induction was inhibited by calphostin C, an inhibitor of PKC. On the other hand, stimulation of PKA by forskolin had a weak suppressive effect on NeuroD mRNA expression. Induction of NeuroD expression was followed by enhancement of expression of the AK1 gene, one of the target genes of NeuroD, which encodes adenylate kinase isozyme 1, an important enzyme in the cellular adenine nucleotide homeostasis. Our results indicate that NeuroD expression is regulated, at least in part, by the PKC pathway and not by the PKA pathway. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.

关键词： adenylate kinase isozyme 1 basic helix-loop-helix NeuroD protein kinase A protein kinase C reverse transcription-polymerase chain reaction

来源：评论

学校读者我要写书评

暂无评论

Identification and analysis of the promoter region of the human NeuroD-related factor (NDRF)

引用

BIOCHIMICA ET BIOPHYSICA ACTA-GENE STRUCTURE AND EXPRESSION 1999年第1期1445卷 142-147页

作者： Kitamura, T Miyachi, T Nakamura, S Kawakami, H Hiroshima Univ Sch Med Dept Internal Med 4 Minami Ku Hiroshima 7348551 Japan

We isolated and characterized the human NeuroD-related factor (NDRF)/NeuroD2/KW8 gene. The NDRF gene consisted of two exons and one intron. NDRF had one transcriptional starting point, and in its 5'-flanking region, no TATA box was detected, but 16 E boxes (CANNTG) were present. RNA blotting analysis revealed that HIT-T15 and D283 cells expressed a 3.3 kb band of the NDRF transcript. Promoter analysis by luciferase assay demonstrated that luciferase activity changed between -120 and -195, and between -451 and -564, both regions wherein a single E box existed. Radiation hybrid mapping showed that NDRF linked the marker SHGC-36242 with a LOD score of 8.53 and was located on 17q12-22. (C) 1999 Elsevier Science B.V. All rights reserved.

关键词： NeuroD-related factor/NeuroD2/KW8 neurogenesis promoter basic helix-loop-helix E box

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：