scholarly journals MK2 degradation as a sensor of signal intensity that controls stress-induced cell fate

2021 ◽  
Vol 118 (29) ◽  
pp. e2024562118
Author(s):  
Nuria Gutierrez-Prat ◽  
Monica Cubillos-Rojas ◽  
Begoña Cánovas ◽  
Antonija Kuzmanic ◽  
Jalaj Gupta ◽  
...  
Keyword(s):  
Cell Survival ◽  
Cell Fate ◽  
Mammalian Cells ◽  
Activation Patterns ◽  
Cell Life ◽  
Pathway Activation ◽  
Lysine Residues ◽  
Mdm2 Expression ◽  
Response To Stress ◽  
Stressed Cells

Cell survival in response to stress is determined by the coordination of various signaling pathways. The kinase p38α is activated by many stresses, but the intensity and duration of the signal depends on the stimuli. How different p38α-activation dynamics may impact cell life/death decisions is unclear. Here, we show that the p38α-signaling output in response to stress is modulated by the expression levels of the downstream kinase MK2. We demonstrate that p38α forms a complex with MK2 in nonstimulated mammalian cells. Upon pathway activation, p38α phosphorylates MK2, the complex dissociates, and MK2 is degraded. Interestingly, transient p38α activation allows MK2 reexpression, reassembly of the p38α–MK2 complex, and cell survival. In contrast, sustained p38α activation induced by severe stress interferes with p38α–MK2 interaction, resulting in irreversible MK2 loss and cell death. MK2 degradation is mediated by the E3 ubiquitin ligase MDM2, and we identify four lysine residues in MK2 that are directly ubiquitinated by MDM2. Expression of an MK2 mutant that cannot be ubiquitinated by MDM2 enhances the survival of stressed cells. Our results indicate that MK2 reexpression and binding to p38α is critical for cell viability in response to stress and illustrate how particular p38α-activation patterns induced by different signals shape the stress-induced cell fate.

Multi-scale modeling of cell survival and death mediated by the p53 network: a systems pharmacology framework

2015 ◽  
Vol 11 (11) ◽  
pp. 3011-3021 ◽  
Author(s):  
Yuan Wang ◽  
Zihu Guo ◽  
Xuetong Chen ◽  
Wenjuan Zhang ◽  
Aiping Lu ◽  
...  
Keyword(s):  
Cell Survival ◽  
Cell Fate ◽  
Mammalian Cells ◽  
Regulatory Process ◽  
Systems Pharmacology ◽  
Multi Scale ◽  
Scale Modeling ◽  
Multi Scale Modeling ◽  
P53 Network

The determination of cell fate is a key regulatory process for the development of complex organisms that are controlled by distinct genes in mammalian cells.

scholarly journals Dual Regulation of c-Myc by p300 via Acetylation-Dependent Control of Myc Protein Turnover and Coactivation of Myc-Induced Transcription

2005 ◽  
Vol 25 (23) ◽  
pp. 10220-10234 ◽  
Author(s):  
Francesco Faiola ◽  
Xiaohui Liu ◽  
Szuying Lo ◽  
Songqin Pan ◽  
Kangling Zhang ◽  
...  
Keyword(s):  
Dna Binding ◽  
Cell Fate ◽  
Mammalian Cells ◽  
Dependent Manner ◽  
Dual Roles ◽  
Human Telomerase Reverse Transcriptase ◽  
Lysine Residues ◽  
Human Telomerase

ABSTRACT The c-Myc oncoprotein (Myc) controls cell fate by regulating gene transcription in association with a DNA-binding partner, Max. While Max lacks a transcription regulatory domain, the N terminus of Myc contains a transcription activation domain (TAD) that recruits cofactor complexes containing the histone acetyltransferases (HATs) GCN5 and Tip60. Here, we report a novel functional interaction between Myc TAD and the p300 coactivator-acetyltransferase. We show that p300 associates with Myc in mammalian cells and in vitro through direct interactions with Myc TAD residues 1 to 110 and acetylates Myc in a TAD-dependent manner in vivo at several lysine residues located between the TAD and DNA-binding domain. Moreover, the Myc:Max complex is differentially acetylated by p300 and GCN5 and is not acetylated by Tip60 in vitro, suggesting distinct functions for these acetyltransferases. Whereas p300 and CBP can stabilize Myc independently of acetylation, p300-mediated acetylation results in increased Myc turnover. In addition, p300 functions as a coactivator that is recruited by Myc to the promoter of the human telomerase reverse transcriptase gene, and p300/CBP stimulates Myc TAD-dependent transcription in a HAT domain-dependent manner. Our results suggest dual roles for p300/CBP in Myc regulation: as a Myc coactivator that stabilizes Myc and as an inducer of Myc instability via direct Myc acetylation.

scholarly journals In vivo bioluminescence for tracking cell fate and function

2011 ◽  
Vol 301 (3) ◽  
pp. H663-H671 ◽  
Author(s):  
Patricia E. de Almeida ◽  
Juliaan R. M. van Rappard ◽  
Joseph C. Wu
Keyword(s):  
Gene Expression ◽  
Cell Survival ◽  
Cell Fate ◽  
Mammalian Cells ◽  
Cardiac Injury ◽  
Therapeutic Interventions ◽  
Luciferase Expression ◽  
Physiological Processes ◽  
And Function

Tracking the fate and function of cells in vivo is paramount for the development of rational therapies for cardiac injury. Bioluminescence imaging (BLI) provides a means for monitoring physiological processes in real time, ranging from cell survival to gene expression to complex molecular processes. In mice and rats, BLI provides unmatched sensitivity because of the absence of endogenous luciferase expression in mammalian cells and the low background luminescence emanating from animals. In the field of stem cell therapy, BLI provides an unprecedented means to monitor the biology of these cells in vivo, giving researchers a greater understanding of their survival, migration, immunogenicity, and potential tumorigenicity in a living animal. In addition to longitudinal monitoring of cell survival, BLI is a useful tool for semiquantitative measurements of gene expression in vivo, allowing a better optimization of drug and gene therapies. Overall, this technology not only enables rapid, reproducible, and quantitative monitoring of physiological processes in vivo but also can measure the influences of therapeutic interventions on the outcome of cardiac injuries.

Use of Flexible Materials with a Novel Pressure Driven Equibiaxial Cell Stretching Device for Mechanical Stimulation of Single Mammalian Cells

2003 ◽  
Vol 773 ◽  
Author(s):  
James D. Kubicek ◽  
Stephanie Brelsford ◽  
Philip R. LeDuc
Keyword(s):  
Cell Fate ◽  
Mechanical Stimulation ◽  
Mammalian Cells ◽  
Cellular Response ◽  
Single Cells ◽  
Complex Nature ◽  
Cellular Behavior ◽  
Cell Stretching ◽  
Stimulation Of ◽  
Pressure Driven

AbstractMechanical stimulation of single cells has been shown to affect cellular behavior from the molecular scale to ultimate cell fate including apoptosis and proliferation. In this, the ability to control the spatiotemporal application of force on cells through their extracellular matrix connections is critical to understand the cellular response of mechanotransduction. Here, we develop and utilize a novel pressure-driven equibiaxial cell stretching device (PECS) combined with an elastomeric material to control specifically the mechanical stimulation on single cells. Cells were cultured on silicone membranes coated with molecular matrices and then a uniform pressure was introduced to the opposite surface of the membrane to stretch single cells equibiaxially. This allowed us to apply mechanical deformation to investigate the complex nature of cell shape and structure. These results will enhance our knowledge of cellular and molecular function as well as provide insights into fields including biomechanics, tissue engineering, and drug discovery.

scholarly journals Notch Signaling Regulation in HCC: From Hepatitis Virus to Non-Coding RNAs

Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 521
Author(s):  
Catia Giovannini ◽  
Francesca Fornari ◽  
Fabio Piscaglia ◽  
Laura Gramantieri
Keyword(s):  
Notch Signaling ◽  
Cell Fate ◽  
Hepatitis Virus ◽  
Notch Pathway ◽  
Notch Receptor ◽  
Gamma Secretase ◽  
Stem Cell Maintenance ◽  
Pathway Activation ◽  
Promising Therapeutic Approach ◽  
Conserved Genes

The Notch family includes evolutionary conserved genes that encode for single-pass transmembrane receptors involved in stem cell maintenance, development and cell fate determination of many cell lineages. Upon activation by different ligands, and depending on the cell type, Notch signaling plays pleomorphic roles in hepatocellular carcinoma (HCC) affecting neoplastic growth, invasion capability and stem like properties. A specific knowledge of the deregulated expression of each Notch receptor and ligand, coupled with resultant phenotypic changes, is still lacking in HCC. Therefore, while interfering with Notch signaling might represent a promising therapeutic approach, the complexity of Notch/ligands interactions and the variable consequences of their modulations raises concerns when performed in undefined molecular background. The gamma-secretase inhibitors (GSIs), representing the most utilized approach for Notch inhibition in clinical trials, are characterized by important adverse effects due to the non-specific nature of GSIs themselves and to the lack of molecular criteria guiding patient selection. In this review, we briefly summarize the mechanisms involved in Notch pathway activation in HCC supporting the development of alternatives to the γ-secretase pan-inhibitor for HCC therapy.

scholarly journals Crosstalk of the Caspase Family and Mammalian Target of Rapamycin Signaling

2021 ◽  
Vol 22 (2) ◽  
pp. 817
Author(s):  
Junfang Yan ◽  
Yi Xie ◽  
Jing Si ◽  
Lu Gan ◽  
Hongyan Li ◽  
...  
Keyword(s):  
Cell Growth ◽  
Cell Survival ◽  
Cell Fate ◽  
Cellular Stress ◽  
Mammalian Target Of Rapamycin ◽  
Mtor Signaling ◽  
Target Of Rapamycin ◽  
Dependent Manner ◽  
Caspase Family ◽  
Mediate Cell

Cell can integrate the caspase family and mammalian target of rapamycin (mTOR) signaling in response to cellular stress triggered by environment. It is necessary here to elucidate the direct response and interaction mechanism between the two signaling pathways in regulating cell survival and determining cell fate under cellular stress. Members of the caspase family are crucial regulators of inflammation, endoplasmic reticulum stress response and apoptosis. mTOR signaling is known to mediate cell growth, nutrition and metabolism. For instance, over-nutrition can cause the hyperactivation of mTOR signaling, which is associated with diabetes. Nutrition deprivation can inhibit mTOR signaling via SH3 domain-binding protein 4. It is striking that Ras GTPase-activating protein 1 is found to mediate cell survival in a caspase-dependent manner against increasing cellular stress, which describes a new model of apoptosis. The components of mTOR signaling-raptor can be cleaved by caspases to control cell growth. In addition, mTOR is identified to coordinate the defense process of the immune system by suppressing the vitality of caspase-1 or regulating other interferon regulatory factors. The present review discusses the roles of the caspase family or mTOR pathway against cellular stress and generalizes their interplay mechanism in cell fate determination.

scholarly journals Molecular chaperones and heat shock proteins in atherosclerosis

2012 ◽  
Vol 302 (3) ◽  
pp. H506-H514 ◽  
Author(s):  
Qingbo Xu ◽  
Bernhard Metzler ◽  
Marjan Jahangiri ◽  
Kaushik Mandal
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Molecular Chaperones ◽  
Mammalian Cells ◽  
Vessel Wall ◽  
Protective Role ◽  
Research Field ◽  
Stressed Cells ◽  
Shock Proteins ◽  
Prevention Of Atherosclerosis

In response to stress stimuli, mammalian cells activate an ancient signaling pathway leading to the transient expression of heat shock proteins (HSPs). HSPs are a family of proteins serving as molecular chaperones that prevent the formation of nonspecific protein aggregates and assist proteins in the acquisition of their native structures. Physiologically, HSPs play a protective role in the homeostasis of the vessel wall but have an impact on immunoinflammatory processes in pathological conditions involved in the development of atherosclerosis. For instance, some members of HSPs have been shown to have immunoregulatory properties and modification of innate and adaptive response to HSPs, and can protect the vessel wall from the disease. On the other hand, a high degree of sequence homology between microbial and mammalian HSPs, due to evolutionary conservation, carries a risk of misdirected autoimmunity against HSPs expressed on the stressed cells of vascular endothelium. Furthermore, HSPs and anti-HSP antibodies have been shown to elicit production of proinflammatory cytokines. Potential therapeutic use of HSP in prevention of atherosclerosis involves achieving optimal balance between protective and immunogenic effects of HSPs and in the progress of research on vaccination. In this review, we update the progress of studies on HSPs and the integrity of the vessel wall, discuss the mechanism by which HSPs exert their role in the disease development, and highlight the potential clinic translation in the research field.

scholarly journals Genetic control of programmed cell death in the Caenorhabditis elegans hermaphrodite germline

Development ◽  
1999 ◽  
Vol 126 (5) ◽  
pp. 1011-1022 ◽  
Author(s):  
T.L. Gumienny ◽  
E. Lambie ◽  
E. Hartwieg ◽  
H.R. Horvitz ◽  
M.O. Hengartner
Keyword(s):  
Cell Death ◽  
Caenorhabditis Elegans ◽  
Germ Cell ◽  
Somatic Cell ◽  
Cell Fate ◽  
Germ Cells ◽  
Mapk Pathway ◽  
Apoptotic Cell ◽  
C Elegans ◽  
Pathway Activation

Development of the nematode Caenorhabditis elegans is highly reproducible and the fate of every somatic cell has been reported. We describe here a previously uncharacterized cell fate in C. elegans: we show that germ cells, which in hermaphrodites can differentiate into sperm and oocytes, also undergo apoptotic cell death. In adult hermaphrodites, over 300 germ cells die, using the same apoptotic execution machinery (ced-3, ced-4 and ced-9) as the previously described 131 somatic cell deaths. However, this machinery is activated by a distinct pathway, as loss of egl-1 function, which inhibits somatic cell death, does not affect germ cell apoptosis. Germ cell death requires ras/MAPK pathway activation and is used to maintain germline homeostasis. We suggest that apoptosis eliminates excess germ cells that acted as nurse cells to provide cytoplasmic components to maturing oocytes.

Alterations in an IRE1-RNA complex in the mammalian unfolded protein response

2001 ◽  
Vol 114 (17) ◽  
pp. 3207-3212
Author(s):  
Anne Bertolotti ◽  
David Ron
Keyword(s):  
Unfolded Protein Response ◽  
Mammalian Cells ◽  
Dynamic Change ◽  
Rna Molecules ◽  
Unfolded Protein ◽  
Rna Fragments ◽  
Stressed Cells ◽  
Rna Complex ◽  
Protein Response

IRE1 proteins mediate cellular responses to accumulation of malfolded proteins in the endoplasmic reticulum in the yeast and mammalian unfolded protein responses. A sensitive in vivo u.v. crosslinking assay showed that IRE1 proteins are intimately associated with RNA in mammalian cells. The IRE1-associated RNA fragments recovered by this assay were different in stressed and unstressed cells. The amount of RNA associated with IRE1 that could be revealed by end-labeling with T4 kinase was greater in IRE1-containing complexes isolated from stressed cells. Furthermore, the RNA fragments recovered from complexes found in stressed cells were shorter than those from unstressed cells, revealing a dynamic change in the IRE1-RNA complex during the UPR. Formation of the complex between IRE1 and RNA was dependent on both the kinase and endonuclease domains of IRE1, and involved pre-existing RNA species. When viewed in the context of the known importance of Ire1p-HAC1 mRNA interactions to the yeast unfolded protein response, these findings suggest that full-length mammalian IRE1s also engage RNA molecules as downstream effectors.

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