scholarly journals Investigation of the Wilson gene ATP7B transcriptional start site and the effect of core promoter alterations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Clemens Höflich ◽  
Angela Brieger ◽  
Stefan Zeuzem ◽  
Guido Plotz
Keyword(s):  
Wilson Disease ◽  
Transcription Initiation ◽  
Transcriptional Activity ◽  
Core Promoter ◽  
Transcriptional Start Site ◽  
Copper Metabolism ◽  
Biologically Relevant ◽  
The Core ◽  
Translational Start

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.

scholarly journals Transcriptional Regulation of PEN-2, a Key Component of the γ-Secretase Complex, by CREB

2006 ◽  
Vol 26 (4) ◽  
pp. 1347-1354 ◽  
Author(s):  
Ruishan Wang ◽  
Yun-wu Zhang ◽  
Ping Sun ◽  
Runzhong Liu ◽  
Xian Zhang ◽  
...  
Keyword(s):  
Transcriptional Regulation ◽  
Transcriptional Activity ◽  
Start Codon ◽  
Gamma Secretase ◽  
Mobility Shift ◽  
Endoproteolytic Cleavage ◽  
Notch Cleavage ◽  
Translational Start

ABSTRACT Gamma-secretase, which is responsible for the intramembranous cleavage of Alzheimer's β-amyloid precursor protein (APP), the signaling receptor Notch, and many other substrates, is a multiprotein complex consisting of at least four components: presenilin (PS), nicastrin, APH-1, and PEN-2. Despite the fact that PEN-2 is known to mediate endoproteolytic cleavage of full-length PS and APH-1 and nicastrin are required for maintaining the stability of the complex, the detailed physiological function of each component remain elusive. Unlike that of PS, the transcriptional regulation of PEN-2, APH-1, and nicastrin has not been investigated. Here, we characterized the upstream regions of the human PEN-2 gene and identified a 238-bp fragment located 353 bp upstream of the translational start codon as the key region necessary for the promoter activity. Further analysis revealed a CREB binding site located in the 238-bp region that is essential for the transcriptional activity of the PEN-2 promoter. Mutation of the CREB site abolished the transcriptional activity of the PEN-2 promoter. Electrophoretic mobility shift assays and chromatin immunoprecipitation analysis showed the binding of CREB to the PEN-2 promoter region both in vitro and in vivo. Activation of the CREB transcriptional factor by forskolin dramatically promoted the expression of PEN-2 mRNA and protein, whereas the other components of the γ-secretase complex remained unaffected. Forskolin treatment slightly increases the secretion of soluble APPα and Aβ without affecting Notch cleavage. These results demonstrate that expression of PEN-2 is regulated by CREB and suggest that the specific control of PEN-2 expression may imply additional physiological functions uniquely assigned to PEN-2.

Repression of cyclin D1: a novel function of MYC

1994 ◽  
Vol 14 (6) ◽  
pp. 4032-4043
Author(s):  
A Philipp ◽  
A Schneider ◽  
I Väsrik ◽  
K Finke ◽  
Y Xiong ◽  
...  
Keyword(s):  
Cyclin D1 ◽  
Transcription Initiation ◽  
Core Promoter ◽  
Constitutive Expression ◽  
Mrna Levels ◽  
Amino Terminal ◽  
3T3 Fibroblasts ◽  
Tata Element

Constitutive expression of human MYC represses mRNA levels of cyclin D1 in proliferating BALB/c-3T3 fibroblasts. We expressed a series of mutant alleles of MYC and found that downregulation of cyclin D1 is distinct from previously described properties of MYC. In particular, we found that association with Max is not required for repression of cyclin D1 by MYC in vivo. Conversely, the integrity of a small amino-terminal region (amino acids 92 to 106) of MYC is critical for repression of cyclin D1 but dispensable for transformation of established RAT1A cells. Runoff transcription assays showed that repression occurs at the level of transcription initiation. We cloned the promoter of the gene for human cyclin D1 and found that it lacks a canonical TATA element. Transcription starts at an initiator element similar to that of the adenovirus major late promoter; this element can be directly bound by USF in vitro. Expression of MYC represses the cyclin D1 promoter via core promoter elements and antagonizes USF-mediated transactivation. Taken together, our data define a new pathway for gene regulation by MYC and show that the cyclin D1 gene is a target gene for repression by MYC.

scholarly journals Dual Negative Control of spx Transcription Initiation from the P3 Promoter by Repressors PerR and YodB in Bacillus subtilis

2006 ◽  
Vol 189 (5) ◽  
pp. 1736-1744 ◽  
Author(s):  
Montira Leelakriangsak ◽  
Kazuo Kobayashi ◽  
Peter Zuber
Keyword(s):  
Oxidative Stress ◽  
Bacillus Subtilis ◽  
Transcription Initiation ◽  
Transcriptional Start Site ◽  
Regulatory Region ◽  
Point Mutations ◽  
Negative Control ◽  
Response To Treatment ◽  
Additive Increase

ABSTRACT The spx gene encodes an RNA polymerase-binding protein that exerts negative and positive transcriptional control in response to oxidative stress in Bacillus subtilis. It resides in the yjbC-spx operon and is transcribed from at least five promoters located in the yjbC regulatory region or in the yjbC-spx intergenic region. Induction of spx transcription in response to treatment with the thiol-specific oxidant diamide is the result of transcription initiation at the P3 promoter located upstream of the spx coding sequence. Previous studies conducted elsewhere and analyses of transcription factor mutants using transformation array technology have uncovered two transcriptional repressors, PerR and YodB, that target the cis-acting negative control elements of the P3 promoter. Expression of an spx-bgaB fusion carrying the P3 promoter is elevated in a yodB or perR mutant, and an additive increase in expression was observed in a yodB perR double mutant. Primer extension analysis of spx RNA shows the same additive increase in P3 transcript levels in yodB perR mutant cells. Purified YodB and PerR repress spx transcription in vitro when wild-type spx P3 promoter DNA was used as a template. Point mutations at positions within the P3 promoter relieved YodB-dependent repression, while a point mutation at position +24 reduced PerR repression. DNase I footprinting analysis showed that YodB protects a region that includes the P3 −10 and −35 regions, while PerR binds to a region downstream of the P3 transcriptional start site. The binding of both repressors is impaired by the treatment of footprinting reactions with diamide or hydrogen peroxide. The study has uncovered a mechanism of dual negative control that relates to the oxidative stress response of gram-positive bacteria.

scholarly journals Differential Expression of the Smb Bacteriocin in Streptococcus mutans Isolates

2008 ◽  
Vol 52 (8) ◽  
pp. 2742-2749 ◽  
Author(s):  
Hideo Yonezawa ◽  
Howard K. Kuramitsu ◽  
Shu-ichi Nakayama ◽  
Jiro Mitobe ◽  
Mizuho Motegi ◽  
...  
Keyword(s):  
Differential Expression ◽  
Streptococcus Mutans ◽  
Transcription Initiation ◽  
Start Codon ◽  
Nucleotide Position ◽  
Start Site ◽  
Low Level ◽  
Translational Start ◽  
High Level

ABSTRACT The two-component lantibiotic Smb is produced by Streptococcus mutans GS5. In the present study, we identified seven strains of S. mutans containing the smb gene cluster. These strains could be classified into high- and low-level Smb producers relative to the levels of Smb production by indicator strains in vitro. This classification was dependent upon the transcription levels of the structural smbA and smbB genes. Sequence analysis upstream of smbA in the high- and low-level Smb-producing strains revealed differences at nucleotide position −46 relative to the smbA start codon. Interestingly, the transcription start site was present upstream of the point mutation, indicating that both groups of strains have the same promoter constructs and that the differential expression of smbA and smbB mRNA occurred subsequent to transcription initiation. In addition, smbA::lacZ fusion expression was higher when it was regulated by the sequences of strains with high-level Smb activity than when it was regulated by the comparable region from strains with low-level Smb activity. Taken together, we conclude that high- or low-level Smb expression is dependent on the presence of a G or a T nucleotide at position −46 relative to the smbA translational start site in S. mutans Smb producers.

scholarly journals Multiple Mechanisms Are Used for Growth Rate and Stringent Control of leuV Transcriptional Initiation inEscherichia coli

1999 ◽  
Vol 181 (18) ◽  
pp. 5771-5782 ◽  
Author(s):  
Dmitry K. Pokholok ◽  
Maria Redlak ◽  
Charles L. Turnbough ◽  
Sara Dylla ◽  
Walter M. Holmes
Keyword(s):  
Growth Rate ◽  
Binding Site ◽  
Transcription Initiation ◽  
Core Promoter ◽  
Cellular Level ◽  
Structural Variants ◽  
Stringent Control ◽  
The Stability

ABSTRACT Expression of the Escherichia coli leuV operon, which contains three tRNA1 Leu genes, is regulated by several mechanisms including growth-rate-dependent control (GRDC) and stringent control (SC). Structural variants of the leuV promoter which differentially affect these regulatory responses have been identified, suggesting that promoter targets for GRDC and SC may be different and that GRDC of the leuV promoter occurs in the absence of guanosine 3′,5′-bisdiphosphate. To determine the mechanisms of the leuV promoter regulation, we have examined the stability of promoter open complexes and the effects of nucleotide triphosphate (NTP) concentration on the efficiency of theleuV promoter and its structural variants in vitro and in vivo. The leuV promoter open complexes were an order of magnitude more stable to heparin challenge than those ofrrnBp 1. The major initiating nucleotide GTP as well as other NTPs increased the stability of the leuVpromoter open complexes. When the cellular level of purine triphosphates was increased at slower growth rates by pyrimidine limitation, a 10% reduction in leuV promoter activity was seen. It therefore appears that transcription initiation from theleuV promoter is less sensitive to changes in intracellular NTP concentration than that from rrnBp 1. Comparative analysis of regulation of the leuV promoter with and without upstream activating sequences (UAS) demonstrated that the binding site for factor of inversion stimulation (FIS) located in UAS is essential for maximal GRDC. Moreover, the presence of UAS overcame the effects of leuV promoter mutations, which abolished GRDC of the leuV core promoter. However, although the presence of putative FIS binding site was essential for optimal GRDC, both mutant and wild-type leuV promoters containing UAS showed improved GRDC in a fis mutant background, suggesting that FIS protein is an important but not unique participant in the regulation of the leuV promoter.

scholarly journals The Core Promoter Is a Regulatory Hub for Developmental Gene Expression

2021 ◽  
Vol 9 ◽  
Author(s):  
Anna Sloutskin ◽  
Hila Shir-Shapira ◽  
Richard N. Freiman ◽  
Tamar Juven-Gershon
Keyword(s):  
Gene Expression ◽  
Transcriptional Activation ◽  
Transcription Initiation ◽  
Promoter Region ◽  
Core Promoter ◽  
Developmental Gene ◽  
Core Promoter Region ◽  
Developmental Gene Expression ◽  
The Core ◽  
Regulatory Module

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.

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