scholarly journals Induction of the mammalian GRP78/BiP gene by Ca2+ depletion and formation of aberrant proteins: activation of the conserved stress-inducible grp core promoter element by the human nuclear factor YY1.

1997 ◽  
Vol 17 (1) ◽  
pp. 54-60 ◽  
Author(s):  
W W Li ◽  
Y Hsiung ◽  
Y Zhou ◽  
B Roy ◽  
A S Lee
Keyword(s):  
Endoplasmic Reticulum ◽  
Transcriptional Activation ◽  
Core Promoter ◽  
Affinity Purification ◽  
Biochemical Properties ◽  
Protein Glycosylation ◽  
Calcium Stores ◽  
Nuclear Factor ◽  
Core Element ◽  
Grp78 Promoter

Previously, we have identified a constitutive nuclear factor, p70CORE, from HeLa cell nuclear extract which interacts specifically with the stress-inducible change region (SICR) of the grp78 promoter. Here we report that p70CORE is identical to YY1, a member of the GLI zinc finger family, by criteria of biochemical properties including apparent molecular weight, binding site homology, immunoreactivity, and affinity purification. Recombinant YY1 binds the double-stranded SICR with high specificity but has no affinity for its single-stranded form. In cotransfection studies, YY1 specifically enhanced the transcriptional activation of the grp78 promoter under a variety of stress conditions: depletion of the endoplasmic reticulum calcium stores, protein glycosylation block, and formation of aberrant proteins by azetidine treatment. In contrast, YY1 has minimal effect on the stress induction of the hsp70 promoter. YY1 enhancement of the grp78 stress response is dependent on its DNA-binding domain, with little effect on the basal expression of the promoter. The effect of YY1 transactivation may be mediated by the highly conserved grp78 core element. This is the first example of the ubiquitous factor YY1 involved in regulating inducible gene expression and its involvement in mediating stress signals generated from the endoplasmic reticulum to the nucleus.

Transcriptional activation of the glucose-regulated protein genes and their heterologous fusion genes by beta-mercaptoethanol

1987 ◽  
Vol 7 (8) ◽  
pp. 2974-2976
Author(s):  
Y K Kim ◽  
A S Lee
Keyword(s):  
Transcriptional Activation ◽  
Mammalian Cells ◽  
Calcium Ionophore ◽  
Calcium Ionophore A23187 ◽  
Protein Glycosylation ◽  
Temperature Sensitive ◽  
Ionophore A23187 ◽  
Grp78 Promoter ◽  
Steady State Levels ◽  
Tata Sequence

The sulfhydryl-reducing agent beta-mercaptoethanol preferentially stimulates the synthesis of glucose-regulated proteins (GRPs) in mammalian cells. The rapid and large increase in GRPs is due to transcriptional activation of GRP94 and GRP78 genes, resulting in a rapid increase in the steady-state levels of GRP transcripts. From analysis of 5'-deletion mutants, the region of beta-mercaptoethanol responsiveness in the GRP78 promoter was mapped within 450 nucleotides upstream of the TATA sequence. This same general region was demonstrated to be important for induction of the GRP78 gene by the calcium ionophore A23187, glucose starvation, and a temperature-sensitive mutation in a K12 cell line defective in protein glycosylation.

scholarly journals Endoplasmic Reticulum Stress Induction of the Grp78/BiP Promoter: Activating Mechanisms Mediated by YY1 and Its Interactive Chromatin Modifiers

2005 ◽  
Vol 25 (11) ◽  
pp. 4529-4540 ◽  
Author(s):  
Peter Baumeister ◽  
Shengzhan Luo ◽  
William C. Skarnes ◽  
Guangchao Sui ◽  
Edward Seto ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Transcription Factor ◽  
Er Stress ◽  
Transcriptional Activation ◽  
Stress Conditions ◽  
Histone H4 ◽  
Stress Induction ◽  
Histone H4 Acetylation ◽  
Grp78 Promoter

ABSTRACT The unfolded protein response is an evolutionarily conserved mechanism whereby cells respond to stress conditions that target the endoplasmic reticulum (ER). The transcriptional activation of the promoter of GRP78/BiP, a prosurvival ER chaperone, has been used extensively as an indicator of the onset of the UPR. YY1, a constitutively expressed multifunctional transcription factor, activates the Grp78 promoter only under ER stress conditions. Previously, in vivo footprinting analysis revealed that the YY1 binding site of the ER stress response element of the Grp78 promoter exhibits ER stress-induced changes in occupancy. Toward understanding the underlying mechanisms of these unique phenomena, we performed chromatin immunoprecipitation analyses, revealing that YY1 only occupies the Grp78 promoter upon ER stress and is mediated in part by the nuclear form of ATF6. We show that YY1 is an essential coactivator of ATF6 and uncover their specific interactive domains. Using small interfering RNA against YY1 and insertional mutation of the gene encoding ATF6α, we provide direct evidence that YY1 and ATF6 are required for optimal stress induction of Grp78. We also discovered enhancement of the ER-stressed induction of the Grp78 promoter through the interaction of YY1 with the arginine methyltransferase PRMT1 and evidence of its action through methylation of the arginine 3 residue on histone H4. Furthermore, we detected ER stress-induced binding of the histone acetyltransferase p300 to the Grp78 promoter and histone H4 acetylation. A model for the ER stress-mediated transcription factor binding and chromatin modifications at the Grp78 promoter leading to its activation is proposed.

scholarly journals Transcriptional activation of the glucose-regulated protein genes and their heterologous fusion genes by beta-mercaptoethanol.

1987 ◽  
Vol 7 (8) ◽  
pp. 2974-2976 ◽  
Author(s):  
Y K Kim ◽  
A S Lee
Keyword(s):  
Transcriptional Activation ◽  
Mammalian Cells ◽  
Calcium Ionophore ◽  
Calcium Ionophore A23187 ◽  
Protein Glycosylation ◽  
Temperature Sensitive ◽  
Ionophore A23187 ◽  
Grp78 Promoter ◽  
Steady State Levels ◽  
Tata Sequence

The sulfhydryl-reducing agent beta-mercaptoethanol preferentially stimulates the synthesis of glucose-regulated proteins (GRPs) in mammalian cells. The rapid and large increase in GRPs is due to transcriptional activation of GRP94 and GRP78 genes, resulting in a rapid increase in the steady-state levels of GRP transcripts. From analysis of 5'-deletion mutants, the region of beta-mercaptoethanol responsiveness in the GRP78 promoter was mapped within 450 nucleotides upstream of the TATA sequence. This same general region was demonstrated to be important for induction of the GRP78 gene by the calcium ionophore A23187, glucose starvation, and a temperature-sensitive mutation in a K12 cell line defective in protein glycosylation.

Transcriptional profiling of genes that are regulated by the endoplasmic reticulum-bound transcription factor AIbZIP/CREB3L4 in prostate cells

2007 ◽  
Vol 31 (2) ◽  
pp. 295-305 ◽  
Author(s):  
Sonia Ben Aicha ◽  
Julie Lessard ◽  
Mélissa Pelletier ◽  
Andréa Fournier ◽  
Ezequiel Calvo ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Transcription Factor ◽  
Blot Hybridization ◽  
Active Form ◽  
Physiological Role ◽  
Protein Processing ◽  
Protein Glycosylation ◽  
Bzip Transcription Factor ◽  
Calcium Stores ◽  
Northern Blot Hybridization

The androgen-regulated protein androgen-induced bZIP (AIbZIP) is a bZIP transcription factor that localizes to the membrane of the endoplasmic reticulum (ER). The physiological role of AIbZIP is unknown, but other ER-bound transcription factors such as ATF6 and SREBPs play a crucial role in the regulation of protein processing and lipid synthesis, respectively. In response to alterations in the intracellular milieu, ATF6 and SREBPs are processed to their transcriptionally active forms by regulated intramembrane proteolysis. In humans, AIbZIP mRNA is expressed in several organs including the pancreas, liver, and gonads, but it is especially abundant in prostate epithelial cells. We therefore used LNCaP human prostate cancer cells as a model to identify stimuli that lead to AIbZIP activation and define the transcriptional targets of AIbZIP. In LNCaP cells, AIbZIP was processed to its transcriptionally active form by drugs that deplete ER calcium stores (i.e., A23187 and caffeine), but it was unaffected by an inhibitor of protein glycosylation (tunicamycin). To identify AIbZIP-regulated genes, we generated LNCaP cell lines that conditionally express the processed form of AIbZIP and used Affymetrix microarrays to screen for AIbZIP-regulated transcripts. Selected genes ( n = 48) were validated by Northern blot hybridization. The results reveal that the downstream targets of AIbZIP include genes that are implicated in protein processing (e.g., BAG3, DNAJC12, KDELR3). Strikingly, a large number of AIbZIP-regulated transcripts encode proteins that are involved in transcriptional regulation, small molecule transport, signal transduction, and metabolism. These results suggest that AIbZIP plays a novel role in cell homeostasis.

scholarly journals CRISPR-based transcriptional activation tool for silent genes in filamentous fungi

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
László Mózsik ◽  
Mirthe Hoekzema ◽  
Niels A. W. de Kok ◽  
Roel A. L. Bovenberg ◽  
Yvonne Nygård ◽  
...  
Keyword(s):  
Filamentous Fungi ◽  
Transcriptional Activation ◽  
Core Promoter ◽  
Crop Protection ◽  
Gene Clusters ◽  
Growth Conditions ◽  
Biosynthetic Gene ◽  
Biosynthetic Gene Clusters ◽  
Fluorescent Reporter ◽  
A Genome

AbstractFilamentous fungi are historically known to be a rich reservoir of bioactive compounds that are applied in a myriad of fields ranging from crop protection to medicine. The surge of genomic data available shows that fungi remain an excellent source for new pharmaceuticals. However, most of the responsible biosynthetic gene clusters are transcriptionally silent under laboratory growth conditions. Therefore, generic strategies for activation of these clusters are required. Here, we present a genome-editing-free, transcriptional regulation tool for filamentous fungi, based on the CRISPR activation (CRISPRa) methodology. Herein, a nuclease-defective mutant of Cas9 (dCas9) was fused to a highly active tripartite activator VP64-p65-Rta (VPR) to allow for sgRNA directed targeted gene regulation. dCas9-VPR was introduced, together with an easy to use sgRNA “plug-and-play” module, into a non-integrative AMA1-vector, which is compatible with several filamentous fungal species. To demonstrate its potential, this vector was used to transcriptionally activate a fluorescent reporter gene under the control of the penDE core promoter in Penicillium rubens. Subsequently, we activated the transcriptionally silent, native P. rubens macrophorin biosynthetic gene cluster by targeting dCas9-VPR to the promoter region of the transcription factor macR. This resulted in the production of antimicrobial macrophorins. This CRISPRa technology can be used for the rapid and convenient activation of silent fungal biosynthetic gene clusters, and thereby aid in the identification of novel compounds such as antimicrobials.

scholarly journals Endoplasmic reticulum and oxidant stress mediate nuclear factor-κB activation in the subfornical organ during angiotensin II hypertension

2015 ◽  
Vol 308 (10) ◽  
pp. C803-C812 ◽  
Author(s):  
Colin N. Young ◽  
Anfei Li ◽  
Frederick N. Dong ◽  
Julie A. Horwath ◽  
Catharine G. Clark ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Endoplasmic Reticulum ◽  
Transcription Factor ◽  
Angiotensin Ii ◽  
Er Stress ◽  
Bioluminescence Imaging ◽  
Nuclear Factor Κb ◽  
Nuclear Factor ◽  
Ang Ii ◽  
Arterial Blood

Endoplasmic reticulum (ER) stress and reactive oxygen species (ROS) generation in the brain circumventricular subfornical organ (SFO) mediate the central hypertensive actions of Angiotensin II (ANG II). However, the downstream signaling events remain unclear. Here we tested the hypothesis that angiotensin type 1a receptors (AT1aR), ER stress, and ROS induce activation of the transcription factor nuclear factor-κB (NF-κB) during ANG II-dependent hypertension. To spatiotemporally track NF-κB activity in the SFO throughout the development of ANG II-dependent hypertension, we used SFO-targeted adenoviral delivery and longitudinal bioluminescence imaging in mice. During low-dose infusion of ANG II, bioluminescence imaging revealed a prehypertensive surge in NF-κB activity in the SFO at a time point prior to a significant rise in arterial blood pressure. SFO-targeted ablation of AT1aR, inhibition of ER stress, or adenoviral scavenging of ROS in the SFO prevented the ANG II-induced increase in SFO NF-κB. These findings highlight the utility of bioluminescence imaging to longitudinally track transcription factor activation during the development of ANG II-dependent hypertension and reveal an AT1aR-, ER stress-, and ROS-dependent prehypertensive surge in NF-κB activity in the SFO. Furthermore, the increase in NF-κB activity before a rise in arterial blood pressure suggests a causal role for SFO NF-κB in the development of ANG II-dependent hypertension.

UV stimulation induces nuclear factor κB (NF-κB) DNA-binding activity but not transcriptional activation

2001 ◽  
Vol 29 (6) ◽  
pp. 688-691 ◽  
Author(s):  
K. J. Campbell ◽  
N. R. Chapman ◽  
N. D. Perkins
Keyword(s):  
Dna Binding ◽  
Transcriptional Activation ◽  
Cellular Response ◽  
Uv Light ◽  
Binding Protein ◽  
Nuclear Factor Κb ◽  
Camp Response Element Binding ◽  
Binding Activity ◽  
Nuclear Factor ◽  
Dna Binding Activity

The cellular response to DNA-damaging agents is partly mediated by DNA-binding transcription factors such as p53 and nuclear factor κB (NF-κB). Typically NF-κB activation is associated with resistance to apoptosis. Following stimulation with UV light however, NF-κB activation has been shown to be required for programmed cell death. To study this effect further and to determine the relationship between NF-κB and p53 function, we have examined the effect of UV light on U2OS cells. UV stimulation resulted in the activation of NF-κB DNA-binding and the induction of p53. Surprisingly, and in contrast with tumour necrosis factor α stimulation, this UV-induced NF-κB was transcriptionally inert. These observations suggest a model in which the NF-κB switch from an anti-apoptotic to a pro-apoptotic role within the cell results from modulation of its ability to stimulate gene expression, possibly as a result of the ability of p53 to sequester transcriptional co-activator proteins such as p300/CREB (cAMP-response-element-binding protein)-binding protein.

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