scholarly journals Energetic Interactions Between Subcellular Organelles in Striated Muscles

2020 ◽  
Vol 8 ◽  
Author(s):  
Jérôme Piquereau ◽  
Vladimir Veksler ◽  
Marta Novotova ◽  
Renée Ventura-Clapier
Keyword(s):  
Striated Muscles ◽  
Subcellular Organelles ◽  
Energetic Interactions

Distribution of c-protein isoforms in sarcomeres of developing chick skeletal muscle

1988 ◽  
Vol 46 ◽  
pp. 226-227
Author(s):  
D. A. Fischman ◽  
J. E. Dennis ◽  
T. Obinata ◽  
H. Takano-Ohmuro
Keyword(s):  
Skeletal Muscles ◽  
Thick Filament ◽  
Protein Isoforms ◽  
Actin Binding ◽  
Striated Muscles ◽  
C Protein ◽  
Sarcomeric Protein ◽  
Thick Filaments ◽  
Cross Bridges ◽  
Bridge Bearing

C-protein is a 150 kDa protein found within the A bands of all vertebrate cross-striated muscles. By immunoelectron microscopy, it has been demonstrated that C-protein is distributed along a series of 7-9 transverse stripes in the medial, cross-bridge bearing zone of each A band. This zone is now termed the C-zone of the sarcomere. Interest in this protein has been sparked by its striking distribution in the sarcomere: the transverse repeat between C-protein stripes is 43 nm, almost exactly 3 times the 14.3 nm axial repeat of myosin cross-bridges along the thick filaments. The precise packing of C-protein in the thick filament is still unknown. It is the only sarcomeric protein which binds to both myosin and actin, and the actin-binding is Ca-sensitive. In cardiac and slow, but not fast, skeletal muscles C-protein is phosphorylated. Amino acid composition suggests a protein of little or no αhelical content. Variant forms (isoforms) of C-protein have been identified in cardiac, slow and embryonic muscles.

Dynamics of Regeneration of Striated Muscles in Rats with Posttraumatic Reflex Contractures

2018 ◽  
Vol 9 (3) ◽  
pp. 247-255
Author(s):  
Ulyana D. Matolych ◽  
Victoria V. Pankevych ◽  
Svetlana V. Ushtan
Keyword(s):  
Striated Muscles

Assemblies of D-peptides for Targeting Cell Nucleolus

2019 ◽  
Author(s):  
Huaimin Wang ◽  
Zhaoqianqi Feng ◽  
Weiyi Tan ◽  
Bing Xu
Keyword(s):  
Particle Morphology ◽  
Side Chain ◽  
Mechanism Study ◽  
Structural Analogue ◽  
Hydrophobic Residues ◽  
Subcellular Organelles ◽  
First Case ◽  
New Strategy ◽  
Peptide Derivative ◽  
Peptide Nanoparticles

<p>Selectively targeting cell nucleolus remains a challenge. Here we report the first case that D-peptides form membraneless molecular condensates with RNA for targeting cell nucleolus. A D-peptide derivative, enriched with lysine and hydrophobic residues, self-assembles to form nanoparticles, which enter cells through clathrin dependent endocytosis and mainly accumulate at cell nucleolus. Structural analogue of the D-peptide reveals that particle morphology of the assemblies, which depends on the side chain modification, favors the cellular uptake. Contrasting to those of the D-peptide, the assemblies of the corresponding L-enantiomer largely localize in cell lysosomes. Preliminary mechanism study suggests that the D-peptide nanoparticles interact with RNA to form membraneless condensates in the nucleolus, which further induces DNA damage and results in cell death. This work illustrates a new strategy for rationally designing supramolecular assemblies of D-peptides for targeting subcellular organelles.</p>

Dynamic localization of αB-crystallin at the microtubule cytoskeleton network in beating heart cells

2020 ◽  
Vol 168 (2) ◽  
pp. 125-137 ◽  
Author(s):  
Eri Ohto-Fujita ◽  
Saaya Hayasaki ◽  
Aya Atomi ◽  
Soichiro Fujiki ◽  
Toshiyuki Watanabe ◽  
...  
Keyword(s):  
Cultured Cells ◽  
Resonance Energy Transfer ◽  
Focal Adhesions ◽  
Resonance Energy ◽  
Heart Cells ◽  
Striated Muscles ◽  
Slow Skeletal Muscle ◽  
Αb Crystallin ◽  
Cardiac Muscles ◽  
Myoblast Cells

Abstract αB-crystallin is highly expressed in the heart and slow skeletal muscle; however, the roles of αB-crystallin in the muscle are obscure. Previously, we showed that αB-crystallin localizes at the sarcomere Z-bands, corresponding to the focal adhesions of cultured cells. In myoblast cells, αB-crystallin completely colocalizes with microtubules and maintains cell shape and adhesion. In this study, we show that in beating cardiomyocytes α-tubulin and αB-crystallin colocalize at the I- and Z-bands of the myocardium, where it may function as a molecular chaperone for tubulin/microtubules. Fluorescence recovery after photobleaching (FRAP) analysis revealed that the striated patterns of GFP-αB-crystallin fluorescence recovered quickly at 37°C. FRAP mobility assay also showed αB-crystallin to be associated with nocodazole-treated free tubulin dimers but not with taxol-treated microtubules. The interaction of αB-crystallin and free tubulin was further confirmed by immunoprecipitation and microtubule sedimentation assay in the presence of 1–100 μM calcium, which destabilizes microtubules. Förster resonance energy transfer analysis showed that αB-crystallin and tubulin were at 1–10 nm apart from each other in the presence of colchicine. These results suggested that αB-crystallin may play an essential role in microtubule dynamics by maintaining free tubulin in striated muscles, such as the soleus or cardiac muscles.

scholarly journals Mesoporous Silica Nanoparticles for Targeting Subcellular Organelles

2020 ◽  
Vol 21 (24) ◽  
pp. 9696
Author(s):  
Miguel Gisbert-Garzarán ◽  
Daniel Lozano ◽  
María Vallet-Regí
Keyword(s):  
Mesoporous Silica ◽  
Silica Nanoparticles ◽  
State Of The Art ◽  
Mesoporous Silica Nanoparticles ◽  
Drug Distribution ◽  
Chemical Properties ◽  
Drug Carriers ◽  
Subcellular Organelles ◽  
Physico Chemical ◽  
Tumoral Cells

Current chemotherapy treatments lack great selectivity towards tumoral cells, which leads to nonspecific drug distribution and subsequent side effects. In this regard, the use of nanoparticles able to encapsulate and release therapeutic agents has attracted growing attention. In this sense, mesoporous silica nanoparticles (MSNs) have been widely employed as drug carriers owing to their exquisite physico-chemical properties. Because MSNs present a surface full of silanol groups, they can be easily functionalized to endow the nanoparticles with many different functionalities, including the introduction of moieties with affinity for the cell membrane or relevant compartments within the cell, thus increasing the efficacy of the treatments. This review manuscript will provide the state-of-the-art on MSNs functionalized for targeting subcellular compartments, focusing on the cytoplasm, the mitochondria, and the nucleus.

Analytical Subcellular Fractionation Studies on Rat Liver and on Isolated Jejunal Enterocytes with Special Reference to the Separation of Lysosomes, Peroxisomes and Mitochondria

1976 ◽  
Vol 50 (5) ◽  
pp. 355-366 ◽  
Author(s):  
T. J. Peters ◽  
H. Shio
Keyword(s):  
Rat Liver ◽  
Sucrose Density Gradient ◽  
Subcellular Fractionation ◽  
Low Molecular Weight ◽  
Rat Jejunum ◽  
Marker Enzymes ◽  
Good Separation ◽  
Subcellular Organelles ◽  
Rat Liver Cells ◽  
Isopycnic Centrifugation

1. Enterocytes were isolated from rat jejunum and characterized morphologically. 2. Attempts to separate the enterocyte subcellular organelles, characterized by their marker enzymes, with isopycnic centrifugation were unsuccessful but good separation of peroxisomes, lysosomes and mitochondria was achieved by sedimentation through a shallow sucrose density gradient with a superimposed inverse gradient of low-molecular-weight dextran. 3. The properties and enzyme activities of the principal subcellular organelles in rat liver cells and enterocytes were compared.

scholarly journals E4F1 controls a transcriptional program essential for pyruvate dehydrogenase activity

2016 ◽  
Vol 113 (39) ◽  
pp. 10998-11003 ◽  
Author(s):  
Matthieu Lacroix ◽  
Geneviève Rodier ◽  
Olivier Kirsh ◽  
Thibault Houles ◽  
Hélène Delpech ◽  
...  
Keyword(s):  
Pyruvate Dehydrogenase ◽  
Energy Demand ◽  
Clinical Symptoms ◽  
Tricarboxylic Acid Cycle ◽  
Striated Muscles ◽  
Pyruvate Oxidation ◽  
Mitochondrial Pyruvate Carrier ◽  
Lactic Acidemia ◽  
Transcription Factor 1 ◽  
Dihydrolipoyl Dehydrogenase

The mitochondrial pyruvate dehydrogenase (PDH) complex (PDC) acts as a central metabolic node that mediates pyruvate oxidation and fuels the tricarboxylic acid cycle to meet energy demand. Here, we reveal another level of regulation of the pyruvate oxidation pathway in mammals implicating the E4 transcription factor 1 (E4F1). E4F1 controls a set of four genes [dihydrolipoamide acetlytransferase (Dlat), dihydrolipoyl dehydrogenase (Dld), mitochondrial pyruvate carrier 1 (Mpc1), and solute carrier family 25 member 19 (Slc25a19)] involved in pyruvate oxidation and reported to be individually mutated in human metabolic syndromes. E4F1 dysfunction results in 80% decrease of PDH activity and alterations of pyruvate metabolism. Genetic inactivation of murine E4f1 in striated muscles results in viable animals that show low muscle PDH activity, severe endurance defects, and chronic lactic acidemia, recapitulating some clinical symptoms described in PDC-deficient patients. These phenotypes were attenuated by pharmacological stimulation of PDH or by a ketogenic diet, two treatments used for PDH deficiencies. Taken together, these data identify E4F1 as a master regulator of the PDC.

Sign in / Sign up

Export Citation Format

Share Document