Requirement of New Protein Synthesis of a Transcription Factor for Memory Consolidation: Paradoxical Changes in mRNA and Protein Levels of C/EBP

2006 ◽  
Vol 356 (3) ◽  
pp. 569-577 ◽  
Author(s):  
Dai Hatakeyama ◽  
Hisayo Sadamoto ◽  
Takayuki Watanabe ◽  
Akiko Wagatsuma ◽  
Suguru Kobayashi ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Protein Synthesis ◽  
Memory Consolidation ◽  
Protein Levels ◽  
New Protein

scholarly journals Gain-of-function genetic screen of the kinome reveals BRSK2 as an inhibitor of the NRF2 transcription factor

2019 ◽  
Author(s):  
Tigist Y Tamir ◽  
Brittany M Bowman ◽  
Megan J Agajanian ◽  
Dennis Goldfarb ◽  
Travis P Schrank ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Protein Synthesis ◽  
Human Cancer ◽  
Genetic Screen ◽  
Mtor Signaling ◽  
Negative Regulator ◽  
Dependent Manner ◽  
Gain Of Function ◽  
Protein Levels ◽  
Nrf2 Protein

AbstractNFE2L2/NRF2 is a transcription factor and master regulator of cellular antioxidant response. Aberrantly high NRF2-dependent transcription is recurrent in human cancer, and conversely NRF2 protein levels as well as activity is diminished with age and in neurodegenerative disorders. Though NRF2 activating drugs are clinically beneficial, NRF2 inhibitors do not yet exist. Here we used a gain-of-function genetic screen of the kinome to identify new druggable regulators of NRF2 signaling. We found that the understudied protein kinase Brain Specific Kinase 2 (BRSK2) and the related BRSK1 kinases suppress NRF2-dependent transcription and NRF2 protein levels in an activity-dependent manner. Integrated phosphoproteomics and RNAseq studies revealed that BRSK2 drives AMPK activation and suppresses mTOR signaling. As a result, BRSK2 kinase activation suppressed ribosome-RNA complexes, global protein synthesis, and NRF2 protein levels. Collectively, our data establish the catalytically active BRSK2 kinase as a negative regulator of NRF2 via the AMPK/mTOR signaling. This signaling axis may prove useful for therapeutically targeting NRF2 in human diseases.Summary StatementBRSK2 suppresses NRF2 signaling by inhibiting protein synthesis through mTOR downregulation.

scholarly journals Safety profile of the transcription factor EB (TFEB)-based gene therapy through intracranial injection in mice

2020 ◽  
Vol 11 (1) ◽  
pp. 241-250
Author(s):  
Zhenyu Li ◽  
Guangqian Ding ◽  
Yudi Wang ◽  
Zelong Zheng ◽  
Jianping Lv
Keyword(s):  
Gene Therapy ◽  
Transcription Factor ◽  
Neurodegenerative Diseases ◽  
Brain Tissue ◽  
Inflammatory Responses ◽  
Tissue Samples ◽  
Protein Levels ◽  
Virus Serotype ◽  
Transcription Factor Eb ◽  
The Brain

AbstractTranscription factor EB (TFEB)-based gene therapy is a promising therapeutic strategy in treating neurodegenerative diseases by promoting autophagy/lysosome-mediated degradation and clearance of misfolded proteins that contribute to the pathogenesis of these diseases. However, recent findings have shown that TFEB has proinflammatory properties, raising the safety concerns about its clinical application. To investigate whether TFEB induces significant inflammatory responses in the brain, male C57BL/6 mice were injected with phosphate-buffered saline (PBS), adeno-associated virus serotype 8 (AAV8) vectors overexpressing mouse TFEB (pAAV8-CMV-mTFEB), or AAV8 vectors expressing green fluorescent proteins (GFPs) in the barrel cortex. The brain tissue samples were collected at 2 months after injection. Western blotting and immunofluorescence staining showed that mTFEB protein levels were significantly increased in the brain tissue samples of mice injected with mTFEB-overexpressing vectors compared with those injected with PBS or GFP-overexpressing vectors. pAAV8-CMV-mTFEB injection resulted in significant elevations in the mRNA and protein levels of lysosomal biogenesis indicators in the brain tissue samples. No significant changes were observed in the expressions of GFAP, Iba1, and proinflammation mediators in the pAAV8-CMV-mTFEB-injected brain compared with those in the control groups. Collectively, our results suggest that AAV8 successfully mediates mTFEB overexpression in the mouse brain without inducing apparent local inflammation, supporting the safety of TFEB-based gene therapy in treating neurodegenerative diseases.

scholarly journals The hypoxia sensitive metal transcription factor MTF-1 activates NCX1 brain promoter and participates in remote postconditioning neuroprotection in stroke

2021 ◽  
Vol 12 (5) ◽  
Author(s):  
Valeria Valsecchi ◽  
Giusy Laudati ◽  
Ornella Cuomo ◽  
Rossana Sirabella ◽  
Lucio Annunziato ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Brain Ischemia ◽  
Femoral Artery ◽  
Infarct Volume ◽  
Neuroprotective Effect ◽  
Artery Occlusion ◽  
Sodium Calcium Exchanger ◽  
Protein Levels ◽  
Relevant Role ◽  
Remote Postconditioning

AbstractRemote limb ischemic postconditioning (RLIP) is an experimental strategy in which short femoral artery ischemia reduces brain damage induced by a previous harmful ischemic insult. Ionic homeostasis maintenance in the CNS seems to play a relevant role in mediating RLIP neuroprotection and among the effectors, the sodium-calcium exchanger 1 (NCX1) may give an important contribution, being expressed in all CNS cells involved in brain ischemic pathophysiology. The aim of this work was to investigate whether the metal responsive transcription factor 1 (MTF-1), an important hypoxia sensitive transcription factor, may (i) interact and regulate NCX1, and (ii) play a role in the neuroprotective effect mediated by RLIP through NCX1 activation. Here we demonstrated that in brain ischemia induced by transient middle cerebral occlusion (tMCAO), MTF-1 is triggered by a subsequent temporary femoral artery occlusion (FAO) and represents a mediator of endogenous neuroprotection. More importantly, we showed that MTF-1 translocates to the nucleus where it binds the metal responsive element (MRE) located at −23/−17 bp of Ncx1 brain promoter thus activating its transcription and inducing an upregulation of NCX1 that has been demonstrated to be neuroprotective. Furthermore, RLIP restored MTF-1 and NCX1 protein levels in the ischemic rat brain cortex and the silencing of MTF-1 prevented the increase of NCX1 observed in RLIP protected rats, thus demonstrating a direct regulation of NCX1 by MTF-1 in the ischemic cortex of rat exposed to tMCAO followed by FAO. Moreover, silencing of MTF-1 significantly reduced the neuroprotective effect elicited by RLIP as demonstrated by the enlargement of brain infarct volume observed in rats subjected to RLIP and treated with MTF-1 silencing. Overall, MTF-dependent activation of NCX1 and their upregulation elicited by RLIP, besides unraveling a new molecular pathway of neuroprotection during brain ischemia, might represent an additional mechanism to intervene in stroke pathophysiology.

Lipopolysaccharide-induced sensitization of adenylyl cyclase activity in murine macrophages

2006 ◽  
Vol 290 (1) ◽  
pp. C143-C151 ◽  
Author(s):  
Y. Osawa ◽  
H. T. Lee ◽  
C. A. Hirshman ◽  
D. Xu ◽  
C. W. Emala
Keyword(s):  
Protein Synthesis ◽  
Adenylyl Cyclase ◽  
Actinomycin D ◽  
Inhibitory Effect ◽  
Cytokine Release ◽  
Adenylyl Cyclase Activity ◽  
Phosphorylation State ◽  
Murine Macrophages ◽  
Dependent Pathway ◽  
New Protein

LPS is known to modulate macrophage responses during sepsis, including cytokine release, phagocytosis, and proliferation. Although agents that elevate cAMP reverse LPS-induced macrophage functions, whether LPS itself modulates cAMP and whether LPS-induced decreases in proliferation are modulated via a cAMP-dependent pathway are not known. Murine macrophages (RAW264.7 cells) were treated with LPS in the presence or absence of inhibitors of prostaglandin signaling, protein kinases, CaM, Giproteins, and NF-κB translocation or transcription/translation. LPS effects on CaMKII phosphorylation and the expression of relevant adenylyl cyclase (AC) isoforms were measured. LPS caused a significant dose (5–10,000 ng/ml)- and time (1–8 h)-dependent increase in forskolin-stimulated AC activity that was abrogated by pretreatment with SN50 (an NF-κB inhibitor), actinomycin D, or cycloheximide, indicating that the effect is mediated via NF-κB-dependent transcription and new protein synthesis. Furthermore, LPS decreased the phosphorylation state of CaMKII, and pretreatment with a CaM antagonist attenuated the LPS-induced sensitization of AC. LPS, cAMP, or PKA activation each independently decreased macrophage proliferation. However, inhibition of NF-κB had no effect on LPS-induced decreased proliferation, indicating that LPS-induced decreased macrophage proliferation can proceed via PKA-independent signaling pathways. Taken together, these findings indicate that LPS induces sensitization of AC activity by augmenting the stimulatory effect of CaM and attenuating the inhibitory effect of CaMKII on isoforms of AC that are CaMK sensitive.

The Vitamin D Receptor Represses Transcription of the Pituitary Transcription Factor Pit-1 Gene without Involvement of the Retinoid X Receptor

2006 ◽  
Vol 20 (4) ◽  
pp. 735-748 ◽  
Author(s):  
Samuel Seoane ◽  
Roman Perez-Fernandez
Keyword(s):  
Vitamin D ◽  
Transcription Factor ◽  
Vitamin D Receptor ◽  
Retinoid X Receptor ◽  
Breast Adenocarcinoma ◽  
Mobility Shift ◽  
Histone Deacetylase 1 ◽  
Protein Levels ◽  
Repressive Effect ◽  
Mcf 7

Abstract Pituitary transcription factor-1 (Pit-1) plays a key role in cell differentiation during organogenesis of the anterior pituitary, and as a transcriptional activator for the pituitary GH and prolactin genes. However, Pit-1 is also expressed in nonpituitary cell types and tissues. In breast tumors, Pit-1 mRNA and protein levels are increased with respect to normal breast, and in MCF-7 human breast adenocarcinoma cells, Pit-1 increases GH secretion and cell proliferation. We report here that 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] administration to MCF-7 cells induces a significant decrease in Pit-1 mRNA and protein levels. By deletion analyses, we mapped a region (located between −147 and −171 bp from the transcription start site of the Pit-1 gene) that is sufficient for the repressive response to 1,25-(OH)2D3. Gel mobility shift and chromatin immunoprecipitation assays confirmed the direct interaction between the vitamin D receptor (VDR) as homodimer (without the retinoid X receptor), and the Pit-1 promoter, supporting the view that Pit-1 is a direct transcriptional target of VDR. Our data also indicate that recruitment of histone deacetylase 1 is involved in this repressive effect. This ligand-dependent Pit-1 gene inhibition by VDR in the absence of the retinoid X receptor seems to indicate a new mechanism of transcriptional repression by 1,25-(OH)2D3.

Phased Protein Synthesis at Several Circadian Times Does Not Change Protein Levels in Gonyaulax

1996 ◽  
Vol 11 (1) ◽  
pp. 57-67 ◽  
Author(s):  
Paul Markovic ◽  
Till Roenneberg ◽  
David Morse
Keyword(s):  
Protein Synthesis ◽  
Protein Levels

scholarly journals Nerve growth factor withdrawal-induced cell death in neuronal PC12 cells resembles that in sympathetic neurons.

1992 ◽  
Vol 119 (6) ◽  
pp. 1669-1680 ◽  
Author(s):  
P W Mesner ◽  
T R Winters ◽  
S H Green
Keyword(s):  
Cell Death ◽  
Protein Synthesis ◽  
Nerve Growth Factor ◽  
Growth Factor ◽  
Programmed Cell Death ◽  
Pc12 Cells ◽  
Sympathetic Neurons ◽  
Nerve Growth ◽  
Neuronal Pc12 Cells ◽  
New Protein

Previous studies have shown that in neuronal cells the developmental phenomenon of programmed cell death is an active process, requiring synthesis of both RNA and protein. This presumably reflects a requirement for novel gene products to effect cell death. It is shown here that the death of nerve growth factor-deprived neuronal PC12 cells occurs at the same rate as that of rat sympathetic neurons and, like rat sympathetic neurons, involves new transcription and translation. In nerve growth factor-deprived neuronal PC12 cells, a decline in metabolic activity, assessed by uptake of [3H]2-deoxyglucose, precedes the decline in cell number, assessed by counts of trypan blue-excluding cells. Both declines are prevented by actinomycin D and anisomycin. In contrast, the death of nonneuronal (chromaffin-like) PC12 cells is not inhibited by transcription or translation inhibitors and thus does not require new protein synthesis. DNA fragmentation by internucleosomal cleavage does not appear to be a consistent or significant aspect of cell death in sympathetic neurons, neuronal PC12 cells, or nonneuronal PC12 cells, notwithstanding that the putative nuclease inhibitor aurintricarboxylic acid protects sympathetic neurons, as well as neuronal and nonneuronal PC12 cells, from death induced by trophic factor removal. Both phenotypic classes of PC12 cells respond to aurintricarboxylic acid with similar dose-response characteristics. Our results indicate that programmed cell death in neuronal PC12 cells, but not in nonneuronal PC12 cells, resembles programmed cell death in sympathetic neurons in significant mechanistic aspects: time course, role of new protein synthesis, and lack of a significant degree of DNA fragmentation.

scholarly journals Acquired Glucocorticoid Resistance Due to Homologous Glucocorticoid Receptor Downregulation: A Modern Look at an Age-Old Problem

Cells ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2529
Author(s):  
Lee-Maine L. Spies ◽  
Nicolette J. D. Verhoog ◽  
Ann Louw
Keyword(s):  
Transcription Factor ◽  
Side Effects ◽  
Pharmaceutical Industry ◽  
Glucocorticoid Receptor ◽  
Steroid Hormones ◽  
Molecular Mechanisms ◽  
Protein Levels ◽  
Current Review ◽  
Role Players ◽  
Receptor Conformation

For over 70 years, the unique anti-inflammatory properties of glucocorticoids (GCs), which mediate their effects via the ligand-activated transcription factor, the glucocorticoid receptor alpha (GRα), have allowed for the use of these steroid hormones in the treatment of various autoimmune and inflammatory-linked diseases. However, aside from the onset of severe side-effects, chronic GC therapy often leads to the ligand-mediated downregulation of the GRα which, in turn, leads to a decrease in GC sensitivity, and effectively, the development of acquired GC resistance. Although the ligand-mediated downregulation of GRα is well documented, the precise factors which influence this process are not well understood and, thus, the development of an acquired GC resistance presents an ever-increasing challenge to the pharmaceutical industry. Recently, however, studies have correlated the dimerization status of the GRα with its ligand-mediated downregulation. Therefore, the current review will be discussing the major role-players in the homologous downregulation of the GRα pool, with a specific focus on previously reported GC-mediated reductions in GRα mRNA and protein levels, the molecular mechanisms through which the GRα functional pool is maintained and the possible impact of receptor conformation on GC-mediated GRα downregulation.

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