scholarly journals Myosin VI Localization and Expression in Striated Muscle Pathology

2014 ◽  
Vol 297 (9) ◽  
pp. 1706-1713 ◽  
Author(s):  
Justyna Karolczak ◽  
Serge Weis ◽  
Elisabeth Ehler ◽  
Biruta Kierdaszuk ◽  
Mariusz Berdyński ◽  
...  
Keyword(s):  
Striated Muscle ◽  
Muscle Pathology ◽  
Myosin Vi

scholarly journals Absence of extraocular muscle pathology in Duchenne's muscular dystrophy: role for calcium homeostasis in extraocular muscle sparing.

1995 ◽  
Vol 182 (2) ◽  
pp. 467-475 ◽  
Author(s):  
T S Khurana ◽  
R A Prendergast ◽  
H S Alameddine ◽  
F M Tomé ◽  
M Fardeau ◽  
...  
Keyword(s):  
Muscular Dystrophy ◽  
Calcium Homeostasis ◽  
Extraocular Muscle ◽  
Striated Muscle ◽  
Extraocular Muscles ◽  
Muscle Pathology ◽  
Dystrophin Deficiency ◽  
Muscle Groups ◽  
Duchenne's Muscular Dystrophy

Duchenne muscular dystrophy (DMD) is characterized by clinical weakness and progressive necrosis of striated muscle as a consequence of dystrophin deficiency. While all skeletal muscle groups are thought to be affected, enigmatically, the extraocular muscles (EOM) appear clinically unaffected. Here we show that dystrophin deficiency does not result in myonecrosis or pathologically elevated levels of intracellular calcium ([Ca2+]i) in EOM. At variance with a previous report, we find no evidence for dystrophin-related protein/utrophin up-regulation in EOM. In vitro experiments demonstrate that extraocular muscles are inherently more resistant to necrosis caused by pharmacologically elevated [Ca2+]i levels when compared with pectoral musculature. We believe that EOM are spared in DMD because of their intrinsic ability to maintain calcium homeostasis better than other striated muscle groups. Our results indicate that modulating levels of [Ca2+]i in muscle may be of potential therapeutic use in DMD.

scholarly journals A Kinase Anchoring Protein 9 Is a Novel Myosin VI Binding Partner That Links Myosin VI with the PKA Pathway in Myogenic Cells

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Justyna Karolczak ◽  
Magdalena Sobczak ◽  
Krzysztof Skowronek ◽  
Maria Jolanta Rędowicz
Keyword(s):  
Striated Muscle ◽  
Proximity Ligation Assay ◽  
Myoblast Differentiation ◽  
Myosin Vi ◽  
Tail Domain ◽  
Myogenic Cells ◽  
Early Endosomes ◽  
Anchoring Protein ◽  
Functional Relevance ◽  
Pka Pathway

Myosin VI (MVI) is a unique motor protein moving towards the minus end of actin filaments unlike other known myosins. Its important role has recently been postulated for striated muscle and myogenic cells. Since MVI functions through interactions of C-terminal globular tail (GT) domain with tissue specific partners, we performed a search for MVI partners in myoblasts and myotubes using affinity chromatography with GST-tagged MVI-GT domain as a bait. A kinase anchoring protein 9 (AKAP9), a regulator of PKA activity, was identified by means of mass spectrometry as a possible MVI interacting partner both in undifferentiated and differentiating myoblasts and in myotubes. Coimmunoprecipitation and proximity ligation assay confirmed that both proteins could interact. MVI and AKAP9 colocalized at Rab5 containing early endosomes. Similarly to MVI, the amount of AKAP9 decreased during myoblast differentiation. However, in MVI-depleted cells, both cAMP and PKA levels were increased and a change in the MVI motor-dependent AKAP9 distribution was observed. Moreover, we found that PKA phosphorylated MVI-GT domain, thus implying functional relevance of MVI-AKAP9 interaction. We postulate that this novel interaction linking MVI with the PKA pathway could be important for targeting AKAP9-PKA complex within cells and/or providing PKA to phosphorylate MVI tail domain.

Ultrastructural Localization of Acid Mucosubstance in Skeletal Muscle

1967 ◽  
Vol 25 ◽  
pp. 52-53 ◽  
Author(s):  
William J. Dougherty ◽  
Samuel S. Spicer
Keyword(s):  
Striated Muscle ◽  
Divalent Cations ◽  
Ultrastructural Localization ◽  
Major Elements ◽  
Frozen Sections ◽  
Thorium Dioxide ◽  
Iron Solution ◽  
Coupling System ◽  
Psoas Muscles ◽  
Formalin Fixed

In recent years, considerable attention has focused on the morphological nature of the excitation-contraction coupling system of striated muscle. Since the study of Porter and Palade, it has become evident that the sarcoplastic reticulum (SR) and transverse tubules constitute the major elements of this system. The problem still exists, however, of determining the mechamisms by which the signal to interdigitate is presented to the thick and thin myofilaments. This problem appears to center on the movement of Ca++ions between myofilaments and SR. Recently, Philpott and Goldstein reported acid mucosubstance associated with the SR of fish branchial muscle using the colloidal thorium dioxide technique, and suggested that this material may serve to bind or release divalent cations such as Ca++. In the present study, Hale's iron solution adapted to electron microscopy was applied to formalin-fixed myofibrils isolated from glycerol-extracted rabbit psoas muscles and to frozen sections of formalin-fixed rat psoas muscles.

Quantitative Freeze Fracture Studies of Gap Junctions in Somatic Cell Hybrids, Their Parents, and Revertants

1976 ◽  
Vol 34 ◽  
pp. 218-219
Author(s):  
W. J. Larsen ◽  
R. Azarnia ◽  
W. R. Loewenstein
Keyword(s):  
Gap Junctions ◽  
Striated Muscle ◽  
Freeze Fracture ◽  
Cell Movement ◽  
Dye Molecules ◽  
Somatic Cell Hybrids ◽  
Cell Coupling ◽  
Normal Cells ◽  
Mediate Cell ◽  
Almost All

Although the physiological significance of the gap junction remains unspecified, these membrane specializations are now recognized as common to almost all normal cells (excluding adult striated muscle and some nerve cells) and are found in organisms ranging from the coelenterates to man. Since it appears likely that these structures mediate the cell-to-cell movement of ions and small dye molecules in some electrical tissues, we undertook this study with the objective of determining whether gap junctions in inexcitable tissues also mediate cell-to-cell coupling.To test this hypothesis, a coupling, human Lesh-Nyhan (LN) cell was fused with a non-coupling, mouse cl-1D cell, and the hybrids, revertants, and parental cells were analysed for coupling with respect both to ions and fluorescein and for membrane junctions with the freeze fracture technique.

Orientation of actin filaments during motion in motility assay

1995 ◽  
Vol 53 ◽  
pp. 52-53
Author(s):  
J. Borejdo ◽  
S. Burlacu
Keyword(s):  
Actin Filaments ◽  
Thin Filament ◽  
Striated Muscle ◽  
Myosin Head ◽  
Classical Method ◽  
Polarization Of Fluorescence ◽  
Single Protein ◽  
Intracellular Organelles ◽  
Change Orientation ◽  
Active Entity

Polarization of fluorescence is a classical method to assess orientation or mobility of macromolecules. It has been a common practice to measure polarization of fluorescence through a microscope to characterize orientation or mobility of intracellular organelles, for example anisotropic bands in striated muscle. Recently, we have extended this technique to characterize single protein molecules. The scientific question concerned the current problem in muscle motility: whether myosin heads or actin filaments change orientation during contraction. The classical view is that the force-generating step in muscle is caused by change in orientation of myosin head (subfragment-1 or SI) relative to the axis of thin filament. The molecular impeller which causes this change resides at the interface between actin and SI, but it is not clear whether only the myosin head or both SI and actin change orientation during contraction. Most studies assume that observed orientational change in myosin head is a reflection of the fact that myosin is an active entity and actin serves merely as a passive "rail" on which myosin moves.

The Advantages of Cryotechniques: Application To Bioluminescent Cells

1990 ◽  
Vol 48 (1) ◽  
pp. 486-487
Author(s):  
Gisèle Nicolas ◽  
Jean-Marie Bassot ◽  
Marie-Thérèse Nicolas
Keyword(s):  
Endoplasmic Reticulum ◽  
Striated Muscle ◽  
Light Emission ◽  
Stable State ◽  
Freeze Substitution ◽  
Initial Step ◽  
Point Of Interest ◽  
Cell Components ◽  
Excellent Preservation ◽  
External Water

The use of fast-freeze fixation (FFF) followed by freeze-substitution (FS) brings substantial advantages which are due to the extreme rapidity of this fixation compared to the conventional one. The initial step, FFF, physically immobilizes most molecules and therefore arrests the biological reactions in a matter of milliseconds. The second step, FS, slowly removes the water content still in solid state and, at the same time, chemically fixes the other cell components in absence of external water. This procedure results in an excellent preservation of the ultrastructure, avoids osmotic artifacts,maintains in situ most soluble substances and keeps up a number of cell activities including antigenicities. Another point of interest is that the rapidity of the initial immobilization enables the capture of unstable structures which, otherwise, would slip towards a more stable state. When combined with electrophysiology, this technique arrests the ultrastructural modifications at a well defined state, allowing a precise timing of the events.We studied the epithelium of the elytra of the scale-worm, Harmothoe lunulata which has excitable, conductible and bioluminescent properties. The intracellular sites of the light emission are paracrystals of endoplasmic reticulum (PER), named photosomes (Fig.1). They are able to flash only when they are coupled with plasma membrane infoldings by dyadic or triadic junctions (Fig.2) basically similar to those of the striated muscle fibers. We have studied them before, during and after stimulation. FFF-FS showed that these complexes are labile structures able to diffentiate and dedifferentiate within milliseconds. Moreover, a transient network of endoplasmic reticulum was captured which we have named intermediate endoplasmic reticulum (IER) surrounding the PER (Fig.1). Numerous gap junctions are found in the membranous infoldings of the junctional complexes (Fig.3). When cryofractured, they cleave unusually (Fig.4-5). It is tempting to suggest that they play an important role in the conduction of the excitation.

POPDC proteins and cardiac function

2019 ◽  
Vol 47 (5) ◽  
pp. 1393-1404 ◽  
Author(s):  
Thomas Brand
Keyword(s):  
Potential Role ◽  
Striated Muscle ◽  
Short Review ◽  
Effector Proteins ◽  
Muscle Disease ◽  
Disease Genes ◽  
Protein Protein Interaction ◽  
Interaction Partners ◽  
And Function

Abstract The Popeye domain-containing gene family encodes a novel class of cAMP effector proteins in striated muscle tissue. In this short review, we first introduce the protein family and discuss their structure and function with an emphasis on their role in cyclic AMP signalling. Another focus of this review is the recently discovered role of POPDC genes as striated muscle disease genes, which have been associated with cardiac arrhythmia and muscular dystrophy. The pathological phenotypes observed in patients will be compared with phenotypes present in null and knockin mutations in zebrafish and mouse. A number of protein–protein interaction partners have been discovered and the potential role of POPDC proteins to control the subcellular localization and function of these interacting proteins will be discussed. Finally, we outline several areas, where research is urgently needed.

Myosin VI Undergoes Cargo-Mediated Dimerization

2009 ◽  
Vol 138 (3) ◽  
pp. 537-548
Author(s):  
Cong Yu ◽  
Wei Feng ◽  
Zhiyi Wei ◽  
Yohei Miyanoiri ◽  
Wenyu Wen ◽  
...  
Keyword(s):  
Myosin Vi

Post-Transcriptional Regulation of Cardiac Sarcomere Protein Titin Through 3’ Untranslated Regions

2013 ◽  
Vol 9 ◽  
Author(s):  
Tara A Shrout
Keyword(s):  
Gene Expression ◽  
Transcriptional Control ◽  
Striated Muscle ◽  
Binding Capacity ◽  
Structural Features ◽  
Neonatal Rat ◽  
Regulatory Control ◽  
Untranslated Regions ◽  
Luciferase Reporter ◽  
Regulatory Effects

Titin is the largest known protein in the human body, and forms the backbone of all striated muscle sarcomeres. The elastic nature of titin is an important component of muscle compliance and functionality. A significant amount of energy is expended to synthesize titin, thus we postulate that titin gene expression is under strict regulatory control in order to conserve cellular resources. In general, gene expression is mediated in part by post-transcriptional control elements located within the 5’ and 3’ untranslated regions (UTRs) of mature mRNA. The 3’UTR in particular contains structural features that affect binding capacity to other RNA components, such as MicroRNA, which control mRNA localization, translation, and degradation. The degree and significance of the regulatory effects mediated by two determined variants of titin’s 3’ UTR were evaluated in Neonatal Rat Ventricular Myocyte and Human Embryonic Kidney cell lines. Recombinant plasmids to transfect these cells lines were engineered by insertion of the variant titin 3’UTR 431- and 1047-base pairs sequences into luciferase reporter vectors. Expression due to an unaltered reporter vector served as the control. Quantitative changes in luciferase activity due to the recombinants proportionally represented the effect titin’s respective 3’UTR conferred on downstream post-transcriptional expression relative to the control. The effect due to titin’s shorter 3’UTR sequence was inconclusive; however, results illustrated that titin’s longer 3’UTR sequence caused a 35 percent decrease in protein expression. Secondary structural analysis of the two sequences revealed differential folding patterns that affect the stability and degree of MicroRNA-binding within titin’s variant 3’UTR sequences.

Skeletal Muscle Pathology

Pathology ◽  
1983 ◽  
Vol 15 (4) ◽  
pp. 511
Author(s):  
J.G. McLeod
Keyword(s):  
Skeletal Muscle ◽  
Muscle Pathology
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