scholarly journals Identification of SNAPc Subunit Domains That Interact with Specific Nucleotide Positions in the U1 and U6 Gene Promoters

2010 ◽  
Vol 30 (21) ◽  
pp. 5257-5257 ◽  
Author(s):  
Mun Kyoung Kim ◽  
Yoon Soon Kang ◽  
Hsien-Tsung Lai ◽  
Nermeen H. Barakat ◽  
Deodato Magante ◽  
...  
2010 ◽  
Vol 30 (10) ◽  
pp. 2411-2423 ◽  
Author(s):  
Mun Kyoung Kim ◽  
Yoon Soon Kang ◽  
Hsien-Tsung Lai ◽  
Nermeen H. Barakat ◽  
Deodato Magante ◽  
...  

ABSTRACT The small nuclear RNA (snRNA)-activating protein complex (SNAPc) is essential for transcription of genes coding for the snRNAs (U1, U2, etc.). In Drosophila melanogaster, the heterotrimeric DmSNAPc recognizes a 21-bp DNA sequence, the proximal sequence element A (PSEA), located approximately 40 to 60 bp upstream of the transcription start site. Upon binding the PSEA, DmSNAPc establishes RNA polymerase II preinitiation complexes on U1 to U5 promoters but RNA polymerase III preinitiation complexes on U6 promoters. Minor differences in nucleotide sequence of the U1 and U6 PSEAs determine RNA polymerase specificity; moreover, DmSNAPc adopts different conformations on these different PSEAs. We have proposed that such conformational differences in DmSNAPc play a key role in determining the different polymerase specificities of the U1 and U6 promoters. To better understand the structure of DmSNAPc-PSEA complexes, we have developed a novel protocol that combines site-specific protein-DNA photo-cross-linking with site-specific chemical cleavage of the protein. This protocol has allowed us to map regions within each of the three DmSNAPc subunits that contact specific nucleotide positions within the U1 and U6 PSEAs. These data help to establish the orientation of each DmSNAPc subunit on the DNA and have revealed cases in which different domains of the subunits differentially contact the U1 versus U6 PSEAs.


2015 ◽  
Vol 76 (S 01) ◽  
Author(s):  
Georgios Zenonos ◽  
Peter Howard ◽  
Maureen Lyons-Weiler ◽  
Wang Eric ◽  
William LaFambroise ◽  
...  

2018 ◽  
Vol 40 (4) ◽  
pp. 261-267 ◽  
Author(s):  
K Tari ◽  
Z Shamsi ◽  
H Reza Ghafari ◽  
A Atashi ◽  
M Shahjahani ◽  
...  

Chronic lymphocytic leukemia (CLL) is increased proliferation of B-cells with peripheral blood and bone marrow involvement, which is usually observed in older people. Genetic mutations, epigenetic changes and miRs play a role in CLL pathogenesis. Del 11q, del l17q, del 6q, trisomy 12, p53 and IgVH mutations are the most important genetic changes in CLL. Deletion of miR-15a and miR-16a can increase bcl2 gene expression, miR-29 and miR-181 deletions decrease the expression of TCL1, and miR-146a deletion prevents tumor metastasis. Epigenetic changes such as hypo- and hypermethylation, ubiquitination, hypo- and hyperacetylation of gene promoters involved in CLL pathogenesis can also play a role in CLL. Expression of CD38 and ZAP70, presence or absence of mutation in IgVH and P53 mutation are among the factors involved in CLL prognosis. Use of monoclonal antibodies against surface markers of B-cells like anti-CD20 as well as tyrosine kinase inhibitors are the most important therapeutic approaches for CLL.


2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Qi An ◽  
Chenyan Sun ◽  
Ruidi Li ◽  
Shuhui Chen ◽  
Xinpei Gu ◽  
...  

Abstract Background Calcitonin gene-related peptide (CGRP) as a mediator of microglial activation at the transcriptional level may facilitate nociceptive signaling. Trimethylation of H3 lysine 27 (H3K27me3) by enhancer of zeste homolog 2 (EZH2) is an epigenetic mark that regulates inflammatory-related gene expression after peripheral nerve injury. In this study, we explored the relationship between CGRP and H3K27me3 in microglial activation after nerve injury, and elucidated the underlying mechanisms in the pathogenesis of chronic neuropathic pain. Methods Microglial cells (BV2) were treated with CGRP and differentially enrichments of H3K27me3 on gene promoters were examined using ChIP-seq. A chronic constriction injury (CCI) rat model was used to evaluate the role of CGRP on microglial activation and EZH2/H3K27me3 signaling in CCI-induced neuropathic pain. Results Overexpressions of EZH2 and H3K27me3 were confirmed in spinal microglia of CCI rats by immunofluorescence. CGRP treatment induced the increased of H3K27me3 expression in the spinal dorsal horn and cultured microglial cells (BV2) through EZH2. ChIP-seq data indicated that CGRP significantly altered H3K27me3 enrichments on gene promoters in microglia following CGRP treatment, including 173 gaining H3K27me3 and 75 losing this mark, which mostly enriched in regulation of cell growth, phagosome, and inflammation. qRT-PCR verified expressions of representative candidate genes (TRAF3IP2, BCL2L11, ITGAM, DAB2, NLRP12, WNT3, ADAM10) and real-time cell analysis (RTCA) verified microglial proliferation. Additionally, CGRP treatment and CCI increased expressions of ITGAM, ADAM10, MCP-1, and CX3CR1, key mediators of microglial activation in spinal dorsal horn and cultured microglial cells. Such increased effects induced by CCI were suppressed by CGRP antagonist and EZH2 inhibitor, which were concurrently associated with the attenuated mechanical and thermal hyperalgesia in CCI rats. Conclusion Our findings highly indicate that CGRP is implicated in the genesis of neuropathic pain through regulating microglial activation via EZH2-mediated H3K27me3 in the spinal dorsal horn.


Author(s):  
Helen Ray-Jones ◽  
Mikhail Spivakov

AbstractTranscriptional enhancers play a key role in the initiation and maintenance of gene expression programmes, particularly in metazoa. How these elements control their target genes in the right place and time is one of the most pertinent questions in functional genomics, with wide implications for most areas of biology. Here, we synthesise classic and recent evidence on the regulatory logic of enhancers, including the principles of enhancer organisation, factors that facilitate and delimit enhancer–promoter communication, and the joint effects of multiple enhancers. We show how modern approaches building on classic insights have begun to unravel the complexity of enhancer–promoter relationships, paving the way towards a quantitative understanding of gene control.


BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Zhiwei Chen ◽  
Longhua Zhou ◽  
Panpan Jiang ◽  
Ruiju Lu ◽  
Nigel G. Halford ◽  
...  

Abstract Background Sucrose nonfermenting-1 (SNF1)-related protein kinases (SnRKs) play important roles in regulating metabolism and stress responses in plants, providing a conduit for crosstalk between metabolic and stress signalling, in some cases involving the stress hormone, abscisic acid (ABA). The burgeoning and divergence of the plant gene family has led to the evolution of three subfamilies, SnRK1, SnRK2 and SnRK3, of which SnRK2 and SnRK3 are unique to plants. Therefore, the study of SnRKs in crops may lead to the development of strategies for breeding crop varieties that are more resilient under stress conditions. In the present study, we describe the SnRK gene family of barley (Hordeum vulgare), the widespread cultivation of which can be attributed to its good adaptation to different environments. Results The barley HvSnRK gene family was elucidated in its entirety from publicly-available genome data and found to comprise 50 genes. Phylogenetic analyses assigned six of the genes to the HvSnRK1 subfamily, 10 to HvSnRK2 and 34 to HvSnRK3. The search was validated by applying it to Arabidopsis (Arabidopsis thaliana) and rice (Oryza sativa) genome data, identifying 50 SnRK genes in rice (four OsSnRK1, 11 OsSnRK2 and 35 OsSnRK3) and 39 in Arabidopsis (three AtSnRK1, 10 AtSnRK2 and 26 AtSnRK3). Specific motifs were identified in the encoded barley proteins, and multiple putative regulatory elements were found in the gene promoters, with light-regulated elements (LRE), ABA response elements (ABRE) and methyl jasmonate response elements (MeJa) the most common. RNA-seq analysis showed that many of the HvSnRK genes responded to ABA, some positively, some negatively and some with complex time-dependent responses. Conclusions The barley HvSnRK gene family is large, comprising 50 members, subdivided into HvSnRK1 (6 members), HvSnRK2 (10 members) and HvSnRK3 (34 members), showing differential positive and negative responses to ABA.


2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Julen Mendieta-Esteban ◽  
Marco Di Stefano ◽  
David Castillo ◽  
Irene Farabella ◽  
Marc A Marti-Renom

Abstract Chromosome conformation capture (3C) technologies measure the interaction frequency between pairs of chromatin regions within the nucleus in a cell or a population of cells. Some of these 3C technologies retrieve interactions involving non-contiguous sets of loci, resulting in sparse interaction matrices. One of such 3C technologies is Promoter Capture Hi-C (pcHi-C) that is tailored to probe only interactions involving gene promoters. As such, pcHi-C provides sparse interaction matrices that are suitable to characterize short- and long-range enhancer–promoter interactions. Here, we introduce a new method to reconstruct the chromatin structural (3D) organization from sparse 3C-based datasets such as pcHi-C. Our method allows for data normalization, detection of significant interactions and reconstruction of the full 3D organization of the genomic region despite of the data sparseness. Specifically, it builds, with as low as the 2–3% of the data from the matrix, reliable 3D models of similar accuracy of those based on dense interaction matrices. Furthermore, the method is sensitive enough to detect cell-type-specific 3D organizational features such as the formation of different networks of active gene communities.


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