scholarly journals α-tubulin acetylation and detyrosination correlate with starvation-induced autophagy in tobacco cells

2017 ◽  
Author(s):  
Dmytro I. Lytvyn ◽  
Alla I. Yemets ◽  
Yaroslav B. Blume
Keyword(s):  
Metabolic Stress ◽  
Dynamic State ◽  
Tobacco Cell ◽  
Animal Cells ◽  
Suspension Cells ◽  
Post Translational Modifications ◽  
Glucose Depletion ◽  
Tubulin Acetylation ◽  
Nucleosomal Dna ◽  
Microtubular Cytoskeleton

ABSTRACTRecent data has enabled discovery of novel functions of microtubules (MTs) in the regulation of autophagy development under physiologic/stressful conditions in yeast and animal cells. MTs participate in maturation and traffic of autophagosomes through their dynamic state changes and post-translational modifications of tubulin, including acetylation. We demonstrated the involvement of tobacco cell MTs in the development of starvation-induced autophagy via tubulin acetylation and denitrotyrosination. Induced metabolic stress caused by prolonged cultivation of BY-2 suspension cells results in glucose depletion in the culture medium and following increased rates of protein hydrolysis and autophagy. Development of autophagy was strongly accompanied by α-tubulin acetylation and detyrosination. Both post-translational modifications were caused by changes in the molecular microenvironment of the tobacco cell MTs that was revealed via Co-IP assay. The termination of autophagy led to the development of programmed cell death that was characterised by nucleosomal DNA fragmentation and decreases in α-tubulin acetylation and detyrosination. Our data suggest the role of the functional state of MTs in the mediation of plant autophagy via changes in the tubulin microenvironment and in its post-translational modifications.SUMMARY STATEMENTThe main findings cover a possible impact of plant microtubular cytoskeleton to starvation-induced autophagy development. It can be realized by means of tubulin post-translational modifications, acetylation in the first place.

scholarly journals Histone transfer among chaperones

2012 ◽  
Vol 40 (2) ◽  
pp. 357-363 ◽  
Author(s):  
Wallace H. Liu ◽  
Mair E.A. Churchill
Keyword(s):  
Histone H3 ◽  
Histone Chaperone ◽  
Chromatin Assembly ◽  
Histone Chaperones ◽  
Nucleosome Assembly ◽  
Post Translational Modifications ◽  
Chromatin Dynamics ◽  
Nucleosomal Dna ◽  
Chaperone Interactions ◽  
Dependent Processes

The eukaryotic processes of nucleosome assembly and disassembly govern chromatin dynamics, in which histones exchange in a highly regulated manner to promote genome accessibility for all DNA-dependent processes. This regulation is partly carried out by histone chaperones, which serve multifaceted roles in co-ordinating the interactions of histone proteins with modification enzymes, nucleosome remodellers, other histone chaperones and nucleosomal DNA. The molecular details of the processes by which histone chaperones promote delivery of histones among their many functional partners are still largely undefined, but promise to offer insights into epigenome maintenance. In the present paper, we review recent findings on the histone chaperone interactions that guide the assembly of histones H3 and H4 into chromatin. This evidence supports the concepts of histone post-translational modifications and specific histone chaperone interactions as guiding principles for histone H3/H4 transactions during chromatin assembly.

scholarly journals Aluminum-Induced Rapid Changes in the Microtubular Cytoskeleton of Tobacco Cell Lines

2002 ◽  
Vol 43 (2) ◽  
pp. 207-216 ◽  
Author(s):  
Katerina Schwarzerová ◽  
Sylva Zelenková ◽  
Peter Nick ◽  
Zdeňek Opatrný
Keyword(s):  
Cell Lines ◽  
Tobacco Cell ◽  
Microtubular Cytoskeleton ◽  
Rapid Changes

scholarly journals Sensing of nutrients by CPT1C controls SAC1 activity to regulate AMPA receptor trafficking

2020 ◽  
Vol 219 (10) ◽  
Author(s):  
Maria Casas ◽  
Rut Fadó ◽  
José Luis Domínguez ◽  
Aina Roig ◽  
Moena Kaku ◽  
...  
Keyword(s):  
Ampa Receptors ◽  
Cortical Neurons ◽  
Metabolic Stress ◽  
Phosphatidyl Inositol ◽  
Synaptic Function ◽  
Glucose Depletion ◽  
Malonyl Coa ◽  
Dependent Inhibition ◽  
Excitatory Neurotransmission ◽  
The Brain

Carnitine palmitoyltransferase 1C (CPT1C) is a sensor of malonyl-CoA and is located in the ER of neurons. AMPA receptors (AMPARs) mediate fast excitatory neurotransmission in the brain and play a key role in synaptic plasticity. In the present study, we demonstrate across different metabolic stress conditions that modulate malonyl-CoA levels in cortical neurons that CPT1C regulates the trafficking of the major AMPAR subunit, GluA1, through the phosphatidyl-inositol-4-phosphate (PI(4)P) phosphatase SAC1. In normal conditions, CPT1C down-regulates SAC1 catalytic activity, allowing efficient GluA1 trafficking to the plasma membrane. However, under low malonyl-CoA levels, such as during glucose depletion, CPT1C-dependent inhibition of SAC1 is released, facilitating SAC1’s translocation to ER-TGN contact sites to decrease TGN PI(4)P pools and trigger GluA1 retention at the TGN. Results reveal that GluA1 trafficking is regulated by CPT1C sensing of malonyl-CoA and provide the first report of a SAC1 inhibitor. Moreover, they shed light on how nutrients can affect synaptic function and cognition.

scholarly journals AMP kinase regulation of sugar transport in brain capillary endothelial cells during acute metabolic stress

2012 ◽  
Vol 303 (8) ◽  
pp. C806-C814 ◽  
Author(s):  
Anthony J. Cura ◽  
Anthony Carruthers
Keyword(s):  
Endothelial Cells ◽  
Plasma Membrane ◽  
Blood Brain Barrier ◽  
Sugar Transport ◽  
Metabolic Stress ◽  
Brain Barrier ◽  
Glucose Depletion ◽  
Compound C ◽  
Ampk Phosphorylation ◽  
Blood Brain

AMP-dependent kinase (AMPK) and GLUT1-mediated sugar transport in blood-brain barrier endothelial cells are activated during acute cellular metabolic stress. Using murine brain microvasculature endothelium bEnd.3 cells, we show that AMPK phosphorylation and stimulation of 3- O-methylglucose transport by the AMPK agonist AICAR are inhibited in a dose-dependent manner by the AMPK antagonist Compound C. AMPK α1- or AMPK α2-knockdown by RNA interference or AMPK inhibition by Compound C reduces AMPK phosphorylation and 3- O-methylglucose transport stimulation induced by cellular glucose-depletion, by potassium cyanide (KCN), or by carbonyl cyanide- p-trifluoromethoxy-phenylhydrazone (FCCP). Cell surface biotinylation studies reveal that plasma membrane GLUT1 levels are increased two- to threefold by cellular glucose depletion, AICAR or KCN treatment, and that these increases are prevented by Compound C and by AMPK α1- or α2-knockdown. These results support the hypothesis that AMPK activation in blood-brain barrier-derived endothelial cells directs the trafficking of GLUT1 intracellular pools to the plasma membrane, thereby increasing endothelial sugar transport capacity.

scholarly journals αTAT1-induced tubulin acetylation promotes ameloblastoma migration and invasion

2021 ◽  
Author(s):  
Shohei Yoshimoto ◽  
Hiromitsu Morita ◽  
Kazuhiko Okamura ◽  
Akimitsu Hiraki ◽  
Shuichi Hashimoto
Keyword(s):  
Cell Migration ◽  
Eukaryotic Cells ◽  
Migration And Invasion ◽  
Post Translational Modifications ◽  
Alpha Tubulin ◽  
Tubulin Acetylation ◽  
Hollow Cylinders ◽  
Points Of View ◽  
Epithelial Odontogenic Tumor

AbstractAmeloblastoma (AB) is the most common benign epithelial odontogenic tumor occurring in the jawbone. AB is a slowly growing tumor but sometimes shows a locally invasive and an aggressive growth pattern with a marked bone resorption. In addition, the local recurrence and distant metastasis of AB also sometimes occurs, which resembles one of the typical malignant potentials. From these points of view, to understand better the mechanisms of AB cell migration or invasion is necessary for the better clinical therapy and improvements of the patients’ quality of life. Microtubules in eukaryotic cells reveal the shape of hollow cylinders made up of polymerized alpha (α)- and beta (β)-tubulin dimers and form the cytoskeleton together with microfilaments and intermediate filaments. Microtubules play important roles in cell migration by undergoing assembly and disassembly with post-translational modifications. Stability of microtubules caused by their acetylation is involved in cell migration. In this study, we investigated the expression and distribution of acetylated α-tubulin and alpha-tubulin N-acetyltransferase 1 (αTAT1), an enzyme which acetylates Lys-40 in α-tubulin, in AB specimens, and analyzed how tubulin was acetylated by αTAT1 activation in a human AB cell line, AM-1. Finally, we clarified that TGF-β-activated kinase1 (TAK1) was phosphorylated by TGF-β stimulation, then, induced tubulin acetylation via αTAT1 activation, which subsequently activated the migration and invasion of AB cells.

scholarly journals Mitotic Acetylation of Microtubules Promotes Centrosomal PLK1 Recruitment and Is Required to Maintain Bipolar Spindle Homeostasis

Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1859
Author(s):  
Sylvia Fenosoa Rasamizafy ◽  
Claude Delsert ◽  
Gabriel Rabeharivelo ◽  
Julien Cau ◽  
Nathalie Morin ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Mitotic Spindle ◽  
Mitotic Progression ◽  
Post Translational Modifications ◽  
Microtubule Associated Proteins ◽  
Mitotic Kinase ◽  
Tubulin Acetylation ◽  
Associated Proteins ◽  
Spindle Microtubules ◽  
Bipolar Spindles

Tubulin post-translational modifications regulate microtubule properties and functions. Mitotic spindle microtubules are highly modified. While tubulin detyrosination promotes proper mitotic progression by recruiting specific microtubule-associated proteins motors, tubulin acetylation that occurs on specific microtubule subsets during mitosis is less well understood. Here, we show that siRNA-mediated depletion of the tubulin acetyltransferase ATAT1 in epithelial cells leads to a prolonged prometaphase arrest and the formation of monopolar spindles. This results from collapse of bipolar spindles, as previously described in cells deficient for the mitotic kinase PLK1. ATAT1-depleted mitotic cells have defective recruitment of PLK1 to centrosomes, defects in centrosome maturation and thus microtubule nucleation, as well as labile microtubule-kinetochore attachments. Spindle bipolarity could be restored, in the absence of ATAT1, by stabilizing microtubule plus-ends or by increasing PLK1 activity at centrosomes, demonstrating that the phenotype is not just a consequence of lack of K-fiber stability. We propose that microtubule acetylation of K-fibers is required for a recently evidenced cross talk between centrosomes and kinetochores.

scholarly journals The Importance of Glycans of Viral and Host Proteins in Enveloped Virus Infection

2021 ◽  
Vol 12 ◽  
Author(s):  
Yuqing Li ◽  
Dongqi Liu ◽  
Yating Wang ◽  
Wenquan Su ◽  
Gang Liu ◽  
...  
Keyword(s):  
Bilayer Membrane ◽  
Target Cells ◽  
Animal Cells ◽  
Host Proteins ◽  
Post Translational Modifications ◽  
Enveloped Viruses ◽  
Virus Attachment ◽  
Enveloped Virus ◽  
Research Technology ◽  
Novel Virus

Animal viruses are parasites of animal cells that have characteristics such as heredity and replication. Viruses can be divided into non-enveloped and enveloped viruses if a lipid bilayer membrane surrounds them or not. All the membrane proteins of enveloped viruses that function in attachment to target cells or membrane fusion are modified by glycosylation. Glycosylation is one of the most common post-translational modifications of proteins and plays an important role in many biological behaviors, such as protein folding and stabilization, virus attachment to target cell receptors and inhibition of antibody neutralization. Glycans of the host receptors can also regulate the attachment of the viruses and then influence the virus entry. With the development of glycosylation research technology, the research and development of novel virus vaccines and antiviral drugs based on glycan have received increasing attention. Here, we review the effects of host glycans and viral proteins on biological behaviors of viruses, and the opportunities for prevention and treatment of viral infectious diseases.

scholarly journals Essential role of hyperacetylated microtubules in innate immunity escape orchestrated by the EBV-encoded BHRF1 protein

2021 ◽  
Author(s):  
Damien Glon ◽  
G&eacuteraldine Vilmen ◽  
Daniel Perdiz ◽  
Eva Hernandez ◽  
Guillaume Beauclair ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Signaling Pathway ◽  
Mitochondrial Dynamics ◽  
Virus Reactivation ◽  
Post Translational Modifications ◽  
Barr Virus ◽  
Tubulin Acetylation ◽  
Epstein Barr ◽  
Aggresome Formation

Innate immunity constitutes the first line of defense against viruses, in which mitochondria play an important role in the induction of the interferon (IFN) response. BHRF1, a multifunctional viral protein expressed during Epstein-Barr virus reactivation, modulates mitochondrial dynamics and disrupts the IFN signaling pathway. Mitochondria are mobile organelles that move through the cytoplasm thanks to the cytoskeleton and in particular the microtubule (MT) network. MTs undergo various post-translational modifications, among them tubulin acetylation. In this study, we demonstrated that BHRF1 induces MT hyperacetylation to escape innate immunity. Indeed, expression of BHRF1 induces the aggregation of shortened mitochondria next to the nucleus. This mito-aggresome is organized around the centrosome and its formation is MT-dependent. We also observed that the BHRF1-induced hyperacetylation of MTs involves the α-tubulin acetyltransferase ATAT1. Thanks to a non-acetylatable α-tubulin mutant, we demonstrated that this hyperacetylation is necessary for the mito-aggresome formation. We investigated the mechanism leading to the clustering of mitochondria, and we identified dyneins as motors that are required for the mitochondrial aggregation. Finally, we demonstrated that BHRF1 needs MT hyperacetylation to block the induction of the IFN response. Indeed, in the absence of MT hyperacetylation, BHRF1 is unable to initiate the sequestration of mitochondria into autophagosomes, and mitophagy, which is essential to inhibiting the signaling pathway. Therefore, our results reveal the role of the MT network, and its acetylation level, in the induction of a pro-viral mitophagy.

scholarly journals Microtubule acetylation but not detyrosination promotes focal adhesion dynamics and cell migration

2018 ◽  
Author(s):  
Bertille Bance ◽  
Shailaja Seetharaman ◽  
Cécile Leduc ◽  
Batiste Boëda ◽  
Sandrine Etienne-Manneville
Keyword(s):  
Cell Migration ◽  
Focal Adhesion ◽  
Focal Adhesions ◽  
Cell Polarization ◽  
Post Translational Modifications ◽  
Tubulin Acetylation ◽  
Focal Adhesion Turnover ◽  
Regulatory Functions ◽  
Insight Into

AbstractMicrotubules play a crucial role in mesenchymal migration by controlling cell polarity and the turnover of cell adhesive structures on the extracellular matrix. The polarized functions of microtubules imply that microtubules are locally regulated. Here, we investigated the regulation and role of two major tubulin post-translational modifications, acetylation and detyrosination, which have been associated with stable microtubules. Using primary astrocytes in a wound healing assay, we show that these tubulin modifications are independently regulated during cell polarization and differently affect cell migration. In contrast to microtubule detyrosination, αTAT1-mediated microtubule acetylation increases in the vicinity of focal adhesions and promotes cell migration. We further demonstrate that αTAT1 increases focal adhesion turnover by promoting Rab6-positive vesicle fusion at focal adhesions. Our results highlight the specificity of microtubule post-translational modifications and bring new insight into the regulatory functions of tubulin acetylation.

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