scholarly journals Core promoter specificities of the Sp1 and VP16 transcriptional activation domains.

1995 ◽  
Vol 15 (11) ◽  
pp. 5906-5916 ◽  
Author(s):  
K H Emami ◽  
W W Navarre ◽  
S T Smale

The core promoter compositions of mammalian protein-coding genes are highly variable; some contain TATA boxes, some contain initiator (Inr) elements, and others contain both or neither of these basal elements. The underlying reason for this heterogeneity remains a mystery, as recent studies have suggested that TATA-containing and Inr-containing core promoters direct transcription initiation by similar mechanisms and respond similarly to a wide variety of upstream activators. To analyze in greater detail the influence of core promoter structure on transcriptional activation, we compared activation by GAL4-VP16 and Sp1 through synthetic core promoters containing a TATA box, an Inr, or both TATA and Inr. Striking differences were found between the two activators, most notably in the relative strengths of the TATA/Inr and Inr core promoters: the TATA/Inr promoter was much stronger than the Inr promoter when transcription was activated by GAL4-VP16, but the strengths of the two promoters were more comparable when transcription was activated by Sp1. To define the domains of Sp1 responsible for efficient activation through an Inr, several Sp1 deletion mutants were tested as GAL4 fusion proteins. The results reveal that the glutamine-rich activation domains, which previously were found to interact with Drosophila TAF110, preferentially stimulate Inr-containing core promoters. In contrast, efficient activation through TATA appears to require additional domains of Sp1. These results demonstrate that activation domains differ in their abilities to function with specific core promoters, suggesting that the core promoter structure found in a given gene may reflect a preference of the regulators of that gene. Furthermore, the core promoter preference of an activation domain may be related to a specific mechanism of action, which may provide a functional criterion for grouping activation domains into distinct classes.

2019 ◽  
Author(s):  
Wei Fang ◽  
Yi Wen ◽  
Xiangyun Wei

AbstractTissue-specific or cell type-specific transcription of protein-coding genes is controlled by both trans-regulatory elements (TREs) and cis-regulatory elements (CREs). However, it is challenging to identify TREs and CREs, which are unknown for most genes. Here, we describe a protocol for identifying two types of transcription-activating CREs—core promoters and enhancers—of zebrafish photoreceptor type-specific genes. This protocol is composed of three phases: bioinformatic prediction, experimental validation, and characterization of the CREs. To better illustrate the principles and logic of this protocol, we exemplify it with the discovery of the core promoter and enhancer of the mpp5b apical polarity gene (also known as ponli), whose red, green, and blue (RGB) cone-specific transcription requires its enhancer, a member of the rainbow enhancer family. While exemplified with an RGB cone-specific gene, this protocol is general and can be used to identify the core promoters and enhancers of other protein-coding genes.


Author(s):  
Anna Sloutskin ◽  
Hila Shir-Shapira ◽  
Richard N. Freiman ◽  
Tamar Juven-Gershon

The development of multicellular organisms and the uniqueness of each cell are achieved by distinct transcriptional programs. Multiple processes that regulate gene expression converge at the core promoter region, an 80 bp region that directs accurate transcription initiation by RNA polymerase II (Pol II). In recent years, it has become apparent that the core promoter region is not a passive DNA component, but rather an active regulatory module of transcriptional programs. Distinct core promoter compositions were demonstrated to result in different transcriptional outputs. In this mini-review, we focus on the role of the core promoter, particularly its downstream region, as the regulatory hub for developmental genes. The downstream core promoter element (DPE) was implicated in the control of evolutionarily conserved developmental gene regulatory networks (GRNs) governing body plan in both the anterior-posterior and dorsal-ventral axes. Notably, the composition of the basal transcription machinery is not universal, but rather promoter-dependent, highlighting the importance of specialized transcription complexes and their core promoter target sequences as key hubs that drive embryonic development, differentiation and morphogenesis across metazoan species. The extent of transcriptional activation by a specific enhancer is dependent on its compatibility with the relevant core promoter. The core promoter content also regulates transcription burst size. Overall, while for many years it was thought that the specificity of gene expression is primarily determined by enhancers, it is now clear that the core promoter region comprises an important regulatory module in the intricate networks of developmental gene expression.


BMC Genomics ◽  
2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Hemant Gupta ◽  
Khyati Chandratre ◽  
Siddharth Sinha ◽  
Teng Huang ◽  
Xiaobing Wu ◽  
...  

Abstract Background Core promoter controls transcription initiation. However, little is known for core promoter diversity in the human genome and its relationship with diseases. We hypothesized that as a functional important component in the genome, the core promoter in the human genome could be under evolutionary selection, as reflected by its highly diversification in order to adjust gene expression for better adaptation to the different environment. Results Applying the “Exome-based Variant Detection in Core-promoters” method, we analyzed human core-promoter diversity by using the 2682 exome data sets of 25 worldwide human populations sequenced by the 1000 Genome Project. Collectively, we identified 31,996 variants in the core promoter region (− 100 to + 100) of 12,509 human genes (https://dbhcpd.fhs.um.edu.mo). Analyzing the rich variation data identified highly ethnic-specific patterns of core promoter variation between different ethnic populations, the genes with highly variable core promoters, the motifs affected by the variants, and their involved functional pathways. eQTL test revealed that 12% of core promoter variants can significantly alter gene expression level. Comparison with GWAS data we located 163 variants as the GWAS identified traits associated with multiple diseases, half of these variants can alter gene expression. Conclusion Data from our study reals the highly diversified nature of core promoter in the human genome, and highlights that core promoter variation could play important roles not only in gene expression regulation but also in disease predisposition.


1996 ◽  
Vol 16 (4) ◽  
pp. 1367-1375 ◽  
Author(s):  
X Luo ◽  
M Sawadogo

USF is a family of basic helix-loop transcriptional factors that recognizes DNA-binding sites similar to those of the Myc oncoproteins. Here, various functional domains in the mouse USF2 protein were identified and characterized. Indirect immunofluorescence studies with transiently transfected cells revealed that both the basic region and the highly conserved USF-specific region (USR) are involved in the nuclear localization of USF2. Cotransfection assays with deletion mutants containing the DNA-binding domain of either USF2 or GAL4 identified two distinct transcriptional activation domains in USF2, the USR and the exon 5-encoded region. Activity of the exon 5 activation domain was detectable in both assay systems. Within USF2, however, its potency varied with the conformation induced by the surrounding regions, especially that encoded by alternatively spliced exon 4. In contrast, the USR activated transcription only in its natural context upstream of the USF2 basic region and only with reporter constructs containing the adenovirus major late minimal promoter but not the E1b minimal promoter. However, insertion of an initiator element downstream of the TATA box rescued the activity of the USR on the E1b-driven reporters. The USR therefore represents a new type of activation domain whose function depends very strongly on the core promoter context.


2001 ◽  
Vol 21 (4) ◽  
pp. 1145-1154 ◽  
Author(s):  
Mario Mencı́a ◽  
Kevin Struhl

ABSTRACT TFIID, a multiprotein complex comprising the TATA-binding protein (TBP) and TBP-associated factors (TAFs), associates specifically with core promoters and nucleates the assembly the RNA polymerase II transcription machinery. In yeast cells, TFIID is not generally required for transcription, although it plays an important role at many promoters. Understanding of the specific functions and physiological roles of individual TAFs within TFIID has been hampered by the fact that depletion or thermal inactivation of individual TAFs generally results in dissociation of the TFIID complex. We describe here C-terminally deleted derivatives of yeast TAF130 that assemble into normal TFIID complexes but are transcriptionally inactive in vivo. In vivo, these mutant TFIID complexes are dramatically reduced in their ability to associate with all promoters tested. In vitro, a TFIID complex containing a deleted form of TAF130 associates poorly with DNA, but it is unaffected for interacting with transcriptional activation domains. These results suggest that the C-terminal region of TAF130 is required for TFIID to associate with promoters.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Clemens Höflich ◽  
Angela Brieger ◽  
Stefan Zeuzem ◽  
Guido Plotz

AbstractPathogenic genetic variants in the ATP7B gene cause Wilson disease, a recessive disorder of copper metabolism showing a significant variability in clinical phenotype. Promoter mutations have been rarely reported, and controversial data exist on the site of transcription initiation (the core promoter). We quantitatively investigated transcription initiation and found it to be located in immediate proximity of the translational start. The effects human single-nucleotide alterations of conserved bases in the core promoter on transcriptional activity were moderate, explaining why clearly pathogenic mutations within the core promoter have not been reported. Furthermore, the core promoter contains two frequent polymorphisms (rs148013251 and rs2277448) that could contribute to phenotypical variability in Wilson disease patients with incompletely inactivating mutations. However, neither polymorphism significantly modulated ATP7B expression in vitro, nor were copper household parameters in healthy probands affected. In summary, the investigations allowed to determine the biologically relevant site of ATP7B transcription initiation and demonstrated that genetic variations in this site, although being the focus of transcriptional activity, do not contribute significantly to Wilson disease pathogenesis.


1996 ◽  
Vol 16 (3) ◽  
pp. 839-846 ◽  
Author(s):  
E M Newton ◽  
U Knauf ◽  
M Green ◽  
R E Kingston

Heat shock factor (HSF) activates transcription in response to cellular stress. Human HSF1 has a central regulatory domain which can repress the activity of its activation domains at the control temperature and render them heat shock inducible. To determine whether the regulatory domain works in tandem with specific features of the HSF1 transcriptional activation domains, we first used deletion and point mutagenesis to define these activation domains. One of the activation domains can be reduced to just 20 amino acids. A GAL4 fusion protein containing the HSF 1 regulatory domain and this 20-amino-acid activation domain is repressed at the control temperature but potently activates transcription in response to heat shock. No specific amino acids in this activation domain are required for response to the regulatory domain; in particular, none of the potentially phosphorylated serine and threonine residues are required for heat induction, implying that heat-induced phosphorylation of the transcriptional activation domains is not required for induction. The regulatory domain is able to confer heat responsiveness to an otherwise completely heterologous chimeric activator that contains a portion of the VP16 activation domain, suggesting that the regulatory domain can sense heat in the absence of other portions of HSF1.


1994 ◽  
Vol 14 (6) ◽  
pp. 3927-3937
Author(s):  
M Kretzschmar ◽  
G Stelzer ◽  
R G Roeder ◽  
M Meisterernst

We have isolated from a crude Hela cell cofactor fraction (USA) a novel positive cofactor that cooperates with the general transcription machinery to effect efficient stimulation of transcription by GAL4-AH, a derivative of the Saccharomyces cerevisiae regulatory factor GAL4. PC2 was shown to be a 500-kDa protein complex and to be functionally and biochemically distinct from native TFIID and previously identified cofactors. In the presence of native TFIID and other general factors, PC2 was necessary and sufficient for activation by GAL4-AH. Cofactor function was specific for transcriptional activation domains of GAL4-AH. The repressor histone H1 further potentiated but was not required for activation of transcription by GAL4-AH. On the basis of the observation that PC2 exerts entirely positive effects on transcription, we propose a model in which PC2 increases the activity of the preinitiation complex in the presence of an activator, thereby establishing a specific pathway during activation of RNA polymerase II.


2021 ◽  
Vol 90 (1) ◽  
pp. 193-219
Author(s):  
Emmanuel Compe ◽  
Jean-Marc Egly

In eukaryotes, transcription of protein-coding genes requires the assembly at core promoters of a large preinitiation machinery containing RNA polymerase II (RNAPII) and general transcription factors (GTFs). Transcription is potentiated by regulatory elements called enhancers, which are recognized by specific DNA-binding transcription factors that recruit cofactors and convey, following chromatin remodeling, the activating cues to the preinitiation complex. This review summarizes nearly five decades of work on transcription initiation by describing the sequential recruitment of diverse molecular players including the GTFs, the Mediator complex, and DNA repair factors that support RNAPII to enable RNA synthesis. The elucidation of the transcription initiation mechanism has greatly benefited from the study of altered transcription components associated with human diseases that could be considered transcription syndromes.


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