scholarly journals A light-induced protease from barley plastids degrades NADPH:protochlorophyllide oxidoreductase complexed with chlorophyllide.

1995 ◽  
Vol 15 (11) ◽  
pp. 6206-6212 ◽  
Author(s):  
C Reinbothe ◽  
K Apel ◽  
S Reinbothe
Keyword(s):  
Product Formation ◽  
In Vitro Transcription ◽  
Precursor Protein ◽  
Dependent Manner ◽  
Hordeum Vulgare L ◽  
Nadph:Protochlorophyllide Oxidoreductase ◽  
Catalytically Active ◽  
Protease Treatment ◽  
Energy Dependent

The NADPH:protochlorophyllide oxidoreductase precursor protein (pPorA) of barley (Hordeum vulgare L. cv. Carina), synthesized from a full-length cDNA clone by coupling in vitro transcription and translation, is a catalytically active protein. It converts protochlorophyllide to chlorophyllide in a light- and NADPH-dependent manner. At least the pigment product of catalysis remains tightly bound to the precursor protein. The chlorophyllide-pPorA complex differs markedly from the protochlorophyllide-pPorA complex with respect to sensitivity to attack by a light-induced, nucleus-encoded, and energy-dependent protease activity of barley plastids. The pPorA-chlorophyllide complex is rapidly degraded, in contrast to pPorA-protochlorophyllide complexes containing or lacking NADPH, which are both resistant to protease treatment. Unexpectedly, pPorA devoid of its substrates or products was less sensitive to proteolysis than the pPorA-chlorophyllide complex, suggesting that both substrate binding and product formation during catalysis had caused differential changes in protein conformation.

scholarly journals A tridecamer DNA sequence supports human mitochondrial RNA 3'-end formation in vitro.

1988 ◽  
Vol 8 (10) ◽  
pp. 4502-4509 ◽  
Author(s):  
T W Christianson ◽  
D A Clayton
Keyword(s):  
Dna Sequence ◽  
Transcription Termination ◽  
In Vitro Transcription ◽  
Mitochondrial Rna ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Transcription System ◽  
Flanking Regions

Vertebrate mitochondrial genomes contain a putative transcription termination site at the boundary between the genes for 16S rRNA and leucyl-tRNA. We have described previously an in vitro transcription system from human cells with the capacity to generate RNA 3' ends with the same map positions as those synthesized in vivo. By assaying the ability of variously truncated templates to support 3'-end formation, we demonstrated that the tridecamer sequence 5'-TGGCAGAGCCCCGG-3', contained entirely within the gene for leucyl-tRNA, is necessary to direct accurate termination. When two tridecamer sequences and their immediate flanking regions were placed in tandem, termination occurred at both promoter-proximal and promoter-distal sites. Furthermore, termination was competitively inhibited, in a concentration-dependent manner, by DNA containing the tridecamer sequence. These results suggest a modest sequence requirement for transcription termination that is contingent on a factor capable of recognizing the presence of the tridecamer DNA sequence.

scholarly journals Functional Analysis of the Heat Shock Regulator HrcA of Chlamydia trachomatis

2002 ◽  
Vol 184 (23) ◽  
pp. 6566-6571 ◽  
Author(s):  
Adam C. Wilson ◽  
Ming Tan
Keyword(s):  
Heat Shock ◽  
Chlamydia Trachomatis ◽  
In Vitro Transcription ◽  
Negative Regulator ◽  
Heat Shock Gene ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Topological State ◽  
Heat Shock Gene Expression

ABSTRACT HrcA is a regulator of bacterial heat shock gene expression that binds to a cis-acting DNA element called CIRCE. It has been proposed that HrcA and CIRCE function as a repressor-operator pair. We have purified recombinant HrcA from the pathogenic bacterium Chlamydia trachomatis and have shown that it is a DNA-binding protein that functions as a negative regulator of transcription. HrcA bound specifically to the CIRCE element in a concentration-dependent manner. HrcA repressed the in vitro transcription of a chlamydial heat shock promoter, and this repression was promoter specific. HrcA-mediated repression appears to be dependent on the topological state of the promoter, as repression on a supercoiled promoter template was greater than that on a linearized template. These results provide direct support for the role of HrcA as a transcriptional repressor in bacteria. This is the first report of the in vitro reconstitution of transcriptional regulation in Chlamydia.

A tridecamer DNA sequence supports human mitochondrial RNA 3'-end formation in vitro

1988 ◽  
Vol 8 (10) ◽  
pp. 4502-4509
Author(s):  
T W Christianson ◽  
D A Clayton
Keyword(s):  
Dna Sequence ◽  
Transcription Termination ◽  
In Vitro Transcription ◽  
Mitochondrial Rna ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Transcription System ◽  
Flanking Regions

Vertebrate mitochondrial genomes contain a putative transcription termination site at the boundary between the genes for 16S rRNA and leucyl-tRNA. We have described previously an in vitro transcription system from human cells with the capacity to generate RNA 3' ends with the same map positions as those synthesized in vivo. By assaying the ability of variously truncated templates to support 3'-end formation, we demonstrated that the tridecamer sequence 5'-TGGCAGAGCCCCGG-3', contained entirely within the gene for leucyl-tRNA, is necessary to direct accurate termination. When two tridecamer sequences and their immediate flanking regions were placed in tandem, termination occurred at both promoter-proximal and promoter-distal sites. Furthermore, termination was competitively inhibited, in a concentration-dependent manner, by DNA containing the tridecamer sequence. These results suggest a modest sequence requirement for transcription termination that is contingent on a factor capable of recognizing the presence of the tridecamer DNA sequence.

scholarly journals Preparation and Characterization of Callus Extract from Pyrus pyrifolia and Investigation of Its Effects on Skin Regeneration

Cosmetics ◽  
2018 ◽  
Vol 5 (4) ◽  
pp. 71 ◽  
Author(s):  
Dae Park ◽  
Deepak Adhikari ◽  
Rudra Pangeni ◽  
Vijay Panthi ◽  
Hyun Kim ◽  
...  
Keyword(s):  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Fold Increase ◽  
Fibroblast Cell ◽  
Product Formation ◽  
Pyrus Pyrifolia ◽  
Type I ◽  
Dependent Manner ◽  
Procollagen Type

In the present study, an aqueous extract was prepared using calli from the in vitro-derived leaves of Pyrus pyrifolia cultured in Murashige and Skoog medium containing picloram for a plant growth regulator. The major biological components in the callus extract were identified as uridine (1), adenosine (2), and guanosine (3). In terms of the antioxidant activity, at 300 µg/mL, the extract exhibited free radical scavenging activity of 76.9% ± 2.88% in the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, comparable to that of 44 µg/mL ascorbic acid (82.5% ± 3.63%). In addition, the IC50 values for inhibition of advanced glycation end product formation from collagen and elastin were 602 ± 2.72 and 3037 ± 102.5 µg/mL, respectively. The extract significantly promoted keratinocyte and fibroblast cell proliferation in a dose-dependent manner. Moreover, fibroblasts treated with 1.36 µg/mL extract exhibited a 1.60-fold increase in procollagen type I C-peptide level compared to controls. The in vitro wound recovery rates of keratinocytes and fibroblasts were also 75% and 38% greater, respectively, than those of serum-free controls at 9 and 36 h after extract treatment (1.36 µg/mL). Additionally, the extract flux across the human epidermis increased by 1598% after its incorporation into elastic nanoliposomes (NLs). Therefore, elastic NLs loaded with Pyrus pyrifolia callus extract have potential use as skin rejuvenators and antiaging ingredients in cosmetic formulations.

scholarly journals Histone Binding Protein RbAp48 Interacts with a Complex of CREB Binding Protein and Phosphorylated CREB

2000 ◽  
Vol 20 (14) ◽  
pp. 4970-4978 ◽  
Author(s):  
Qinghong Zhang ◽  
Ngan Vo ◽  
Richard H. Goodman
Keyword(s):  
Transcriptional Activation ◽  
Binding Protein ◽  
In Vitro Transcription ◽  
Dependent Manner ◽  
Creb Binding Protein ◽  
Histone Binding ◽  
Nuclear Extracts ◽  
Core Histones ◽  
Phosphorylated Creb

ABSTRACT A CREB-CREB binding protein (CBP) complex was used as bait to screen a mouse embryo cDNA library in yeast. One of the strongest interactions identified the histone binding protein RbAp48. RbAp48 also interacted weakly with CBP alone but did not interact with phosphorylated or nonphosphorylated CREB. CBP (or its homologue p300) from HeLa cell nuclear extracts coimmunoprecipitated with RbAp48 and its homologue RbAp46 and bound to a glutathioneS-transferase–RbAp48 fusion protein. This interaction was stimulated by the addition of phosphorylated CREB and allowed the association of core histones and mononucleosomes in an acetylation-dependent manner. RbAp48 lowered theKm of CBP histone acetylase activity and facilitated p300-mediated in vitro transcription of a chromatinized template in the presence of acetylcoenzyme A. These data indicate that the association of phosphorylated CREB with CBP promotes the binding of RbAp48 and its homologue RbAp46, allowing the formation of a complex that facilitates histone acetylation during transcriptional activation.

scholarly journals Interferon regulatory factors and TFIIB cooperatively regulate interferon-responsive promoter activity in vivo and in vitro.

1996 ◽  
Vol 16 (11) ◽  
pp. 6313-6324 ◽  
Author(s):  
I M Wang ◽  
J C Blanco ◽  
S Y Tsai ◽  
M J Tsai ◽  
K Ozato
Keyword(s):  
In Vitro Transcription ◽  
Specific Factor ◽  
Dependent Manner ◽  
Promoter Activation ◽  
Functional Interaction ◽  
Regulatory Factors ◽  
Protein Protein Interaction ◽  
Interferon Regulatory Factors

Interferon regulatory factors (IRFs) bind to the interferon-stimulated response element (ISRE) and regulate interferon- and virus-mediated gene expression. IRF-1 acts as a transcriptional activator, while IRF-2 acts as a repressor. Here we show that IRF-1 and IRF-2 bind to both cellular TFIIB, a component of the basal transcription machinery, and recombinant TFIIB (rTFIIB) and that this protein-protein interaction facilitates binding of IRFs to the ISRE. A functional interaction between TFIIB and IRF was assessed by a newly established in vitro transcription assay in which recombinant IRF-1 (rIRF-1) stimulated transcription specifically from an ISRE-containing template. With this assay we show that rIRF-1 and rTFIIB cooperatively enhance the ISRE promoter in vitro. We found that the activity of an ISRE-containing promoter was cooperatively enhanced upon cotransfection of TFIIB and IRF-1 cDNAs into P19 embryonal carcinoma cells, further demonstrating functional interactions in vivo. The cooperative enhancement by TFIIB and IRF-1 was independent of the TATA sequence in the ISRE promoter but dependent on the initiator sequence (Inr) and was abolished when P19 cells were induced to differentiate by retinoic acid treatment. In contrast, cotransfection of TFIIB and IRF-1 into NIH 3T3 cells resulted in a dose-dependent repression of promoter activation which occurred in a TATA-dependent manner. Our results indicate the presence of a cell type-specific factor that mediates the functional interaction between IRFs and TFIIB and that acts in conjunction with the requirement of TATA and Inr for promoter activation.

scholarly journals Nitrogen Regulation of the codBA (Cytosine Deaminase) Operon from Escherichia coli by the Nitrogen Assimilation Control Protein, NAC

2003 ◽  
Vol 185 (9) ◽  
pp. 2920-2926 ◽  
Author(s):  
Wilson B. Muse ◽  
Christopher J. Rosario ◽  
Robert A. Bender
Keyword(s):  
Escherichia Coli ◽  
Nitrogen Assimilation ◽  
Cytosine Deaminase ◽  
In Vitro Transcription ◽  
Dependent Manner ◽  
E Coli ◽  
Different Response ◽  
Control Protein

ABSTRACT Transcription of the cytosine deaminase (codBA) operon of Escherichia coli is regulated by nitrogen, with about three times more codBA expression in cells grown in nitrogen-limiting medium than in nitrogen-excess medium. β-Galactosidase expression from codBp-lacZ operon fusions showed that the nitrogen assimilation control protein NAC was necessary for this regulation. In vitro transcription from the codBA promoter with purified RNA polymerase was stimulated by the addition of purified NAC, confirming that no other factors are required. Gel mobility shifts and DNase I footprints showed that NAC binds to a site centered at position −59 relative to the start site of transcription and that mutants that cannot bind NAC there cannot activate transcription. When a longer promoter region (positions −120 to +67) was used, a double footprint was seen with a second 26-bp footprint separated from the first by a hypersensitive site. When a shorter fragment was used (positions −83 to +67), only the primary footprint was seen. Nevertheless, both the shorter and longer fragments showed NAC-mediated regulation in vivo. Cytosine deaminase expression in Klebsiella pneumoniae was also regulated by nitrogen in a NAC-dependent manner. K. pneumoniae differs from E. coli in having two cytosine deaminase genes, an intervening open reading frame between the codB and codA orthologs, and a different response to hypoxanthine which increased cod expression in K. pneumoniae but decreased it in E. coli.

scholarly journals Transcription Activator Interactions with Multiple SWI/SNF Subunits

2002 ◽  
Vol 22 (6) ◽  
pp. 1615-1625 ◽  
Author(s):  
Kristen E. Neely ◽  
Ahmed H. Hassan ◽  
Christine E. Brown ◽  
LeAnn Howe ◽  
Jerry L. Workman
Keyword(s):  
In Vitro Transcription ◽  
Cross Linking ◽  
Dependent Manner ◽  
Transcription Activator ◽  
Activation Domains ◽  
Label Transfer ◽  
Activation Potential ◽  
Transcriptional Stimulation

ABSTRACT We have previously shown that the yeast SWI/SNF complex stimulates in vitro transcription from chromatin templates in an ATP-dependent manner. SWI/SNF function in this regard requires the presence of an activator with which it can interact directly, linking activator recruitment of SWI/SNF to transcriptional stimulation. In this study, we determine the SWI/SNF subunits that mediate its interaction with activators. Using a photo-cross-linking label transfer strategy, we show that the Snf5, Swi1, and Swi2/Snf2 subunits are contacted by the yeast acidic activators, Gcn4 and Hap4, in the context of the intact native SWI/SNF complex. In addition, we show that the same three subunits can interact individually with acidic activation domains, indicating that each subunit contributes to binding activators. Furthermore, mutations that reduce the activation potential of these activators also diminish its interaction with each of these SWI/SNF subunits. Thus, three distinct subunits of the SWI/SNF complex contribute to its interactions with activation domains.

scholarly journals Comprehensive Assessment of the Regulons Controlled by the FixLJ-FixK2-FixK1 Cascade in Bradyrhizobium japonicum

2008 ◽  
Vol 190 (20) ◽  
pp. 6568-6579 ◽  
Author(s):  
Socorro Mesa ◽  
Felix Hauser ◽  
Markus Friberg ◽  
Emmanuelle Malaguti ◽  
Hans-Martin Fischer ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Bradyrhizobium Japonicum ◽  
Regulatory System ◽  
In Vitro Transcription ◽  
Negative Control ◽  
Nitrate Respiration ◽  
Dependent Manner ◽  
New Genes ◽  
Number Of Genes

ABSTRACT Symbiotic N2 fixation in Bradyrhizobium japonicum is controlled by a complex transcription factor network. Part of it is a hierarchically arranged cascade in which the two-component regulatory system FixLJ, in response to a moderate decrease in oxygen concentration, activates the fixK 2 gene. The FixK2 protein then activates not only a number of genes essential for microoxic respiration in symbiosis (fixNOQP and fixGHIS) but also further regulatory genes (rpoN 1, nnrR, and fixK 1). The results of transcriptome analyses described here have led to a comprehensive and expanded definition of the FixJ, FixK2, and FixK1 regulons, which, respectively, consist of 26, 204, and 29 genes specifically regulated in microoxically grown cells. Most of these genes are subject to positive control. Particular attention was addressed to the FixK2-dependent genes, which included a bioinformatics search for putative FixK2 binding sites on DNA (FixK2 boxes). Using an in vitro transcription assay with RNA polymerase holoenzyme and purified FixK2 as the activator, we validated as direct targets eight new genes. Interestingly, the adjacent but divergently oriented fixK 1 and cycS genes shared the same FixK2 box for the activation of transcription in both directions. This recognition site may also be a direct target for the FixK1 protein, because activation of the cycS promoter required an intact fixK 1 gene and either microoxic or anoxic, denitrifying conditions. We present evidence that cycS codes for a c-type cytochrome which is important, but not essential, for nitrate respiration. Two other, unexpected results emerged from this study: (i) specifically FixK1 seemed to exert a negative control on genes that are normally activated by the N2 fixation-specific transcription factor NifA, and (ii) a larger number of genes are expressed in a FixK2-dependent manner in endosymbiotic bacteroids than in culture-grown cells, pointing to a possible symbiosis-specific control.

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