scholarly journals Preparation and properties of myosin native thick filaments from fish dorsal muscle.

1987 ◽  
Vol 53 (6) ◽  
pp. 1073-1082 ◽  
Author(s):  
Motoi Matsuura ◽  
Ken-ichi Arai
Keyword(s):  
Dorsal Muscle ◽  
Thick Filaments

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.

The ultrastructure of the abdominal musculature of an orchestid amphipod

1990 ◽  
Vol 48 (3) ◽  
pp. 464-465
Author(s):  
Martin A. Levin ◽  
Lisa L. Cale ◽  
Valerie Lynch-Holm
Keyword(s):  
Intertidal Zone ◽  
High Water ◽  
Abdominal Muscles ◽  
Abdominal Musculature ◽  
Dorsal Muscle ◽  
High Water Mark ◽  
Thoracic Legs ◽  
Orchestia Cavimana

Orchestia is a genus of amphipod in the crustacean class Malacostraca. The order Amphipoda contains over 6000 species commonly called side swimmers, scuds and beach fleas(1). Most are marine bottom-dwellers utilizing their thoracic legs and posterior abdominal uropods for walking, crawling and swimming. However, some, like those in the genera Orchestia and Hyale are semiterrestrial. These amphipods, commonly referred to as “beach fleas,' “beach hoppers” or “sand fleas” can hop vigorously for great distances (up to 50 times their length) by extending their abdomens and telsons against the sand(2).In our study, the ultrastructure of the dorsal muscle cord of Orchestia grillus was examined. Vogel(3) described the abdominal muscles of Orchestia cavimana as consisting of two groups of muscles: a strong, complex, dorsal muscle cord used mainly for hopping and a group of weaker, ventral, longitudinal and oblique muscles.The specimens were collected in clumps of decaying seaweed and other detritus from the intertidal zone near the high water mark at Avery Point Beach, Connecticut.

Introductory Remarks

1980 ◽  
Vol 38 ◽  
pp. 598-599
Author(s):  
H. Mohri
Keyword(s):  
Muscle Contraction ◽  
Experimental Evidence ◽  
Sea Urchin ◽  
Constant Length ◽  
Thin Filaments ◽  
Bridge Formation ◽  
Thick Filaments ◽  
Sliding Mechanism ◽  
Radial Spokes ◽  
Cilia And Flagella

In 1959, Afzelius observed the presence of two rows of arms projecting from each outer doublet microtubule of the so-called 9 + 2 pattern of cilia and flagella, and suggested a possibility that the outer doublet microtubules slide with respect to each other with the aid of these arms during ciliary and flagellar movement. The identification of the arms as an ATPase, dynein, by Gibbons (1963)strengthened this hypothesis, since the ATPase-bearing heads of myosin molecules projecting from the thick filaments pull the thin filaments by cross-bridge formation during muscle contraction. The first experimental evidence for the sliding mechanism in cilia and flagella was obtained by examining the tip patterns of molluscan gill cilia by Satir (1965) who observed constant length of the microtubules during ciliary bending. Further evidence for the sliding-tubule mechanism was given by Summers and Gibbons (1971), using trypsin-treated axonemal fragments of sea urchin spermatozoa. Upon the addition of ATP, the outer doublets telescoped out from these fragments and the total length reached up to seven or more times that of the original fragment. Thus, the arms on a certain doublet microtubule can walk along the adjacent doublet when the doublet microtubules are disconnected by digestion of the interdoublet links which connect them with each other, or the radial spokes which connect them with the central pair-central sheath complex as illustrated in Fig. 1. On the basis of these pioneer works, the sliding-tubule mechanism has been established as one of the basic mechanisms for ciliary and flagellar movement.

scholarly journals Two LIM Domain Proteins and UNC-96 Link UNC-97/PINCH to Myosin Thick Filaments in Caenorhabditis elegans Muscle

2007 ◽  
Vol 18 (11) ◽  
pp. 4317-4326 ◽  
Author(s):  
Hiroshi Qadota ◽  
Kristina B. Mercer ◽  
Rachel K. Miller ◽  
Kozo Kaibuchi ◽  
Guy M. Benian
Keyword(s):  
Caenorhabditis Elegans ◽  
Binding Assays ◽  
Lim Domain ◽  
Yeast Two Hybrid ◽  
Lim Domains ◽  
Thick Filaments ◽  
Vitro Binding ◽  
Two Hybrid ◽  
Hybrid Screening

By yeast two-hybrid screening, we found three novel interactors (UNC-95, LIM-8, and LIM-9) for UNC-97/PINCH in Caenorhabditis elegans. All three proteins contain LIM domains that are required for binding. Among the three interactors, LIM-8 and LIM-9 also bind to UNC-96, a component of sarcomeric M-lines. UNC-96 and LIM-8 also bind to the C-terminal portion of a myosin heavy chain (MHC), MHC A, which resides in the middle of thick filaments in the proximity of M-lines. All interactions identified by yeast two-hybrid assays were confirmed by in vitro binding assays using purified proteins. All three novel UNC-97 interactors are expressed in body wall muscle and by antibodies localize to M-lines. Either a decreased or an increased dosage of UNC-96 results in disorganization of thick filaments. Our previous studies showed that UNC-98, a C2H2 Zn finger protein, acts as a linkage between UNC-97, an integrin-associated protein, and MHC A in myosin thick filaments. In this study, we demonstrate another mechanism by which this linkage occurs: from UNC-97 through LIM-8 or LIM-9/UNC-96 to myosin.

scholarly journals Urinary Titin N-Fragment as a Biomarker of Muscle Atrophy, Intensive Care Unit-Acquired Weakness, and Possible Application for Post-Intensive Care Syndrome

2021 ◽  
Vol 10 (4) ◽  
pp. 614 ◽  
Author(s):  
Nobuto Nakanishi ◽  
Rie Tsutsumi ◽  
Kanako Hara ◽  
Masafumi Matsuo ◽  
Hiroshi Sakaue ◽  
...  
Keyword(s):  
Intensive Care Unit ◽  
Intensive Care ◽  
Muscle Atrophy ◽  
Critically Ill Patients ◽  
Chronic Illnesses ◽  
Rehabilitation Management ◽  
Muscle Dystrophy ◽  
Thin Filaments ◽  
Thick Filaments ◽  
Post Intensive Care Syndrome

Titin is a giant protein that functions as a molecular spring in sarcomeres. Titin interconnects the contraction of actin-containing thin filaments and myosin-containing thick filaments. Titin breaks down to form urinary titin N-fragments, which are measurable in urine. Urinary titin N-fragment was originally reported to be a useful biomarker in the diagnosis of muscle dystrophy. Recently, the urinary titin N-fragment has been increasingly gaining attention as a novel biomarker of muscle atrophy and intensive care unit-acquired weakness in critically ill patients, in whom titin loss is a possible pathophysiology. Furthermore, several studies have reported that the urinary titin N-fragment also reflected muscle atrophy and weakness in patients with chronic illnesses. It may be used to predict the risk of post-intensive care syndrome or to monitor patients’ condition after hospital discharge for better nutritional and rehabilitation management. We provide several tips on the use of this promising biomarker in post-intensive care syndrome.

scholarly journals The effect of heavy chain phosphorylation and solution conditions on the assembly of Acanthamoeba myosin-II.

1989 ◽  
Vol 109 (4) ◽  
pp. 1529-1535 ◽  
Author(s):  
J H Sinard ◽  
T D Pollard
Keyword(s):  
Light Scattering ◽  
Ionic Strength ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Critical Concentration ◽  
Myosin Ii ◽  
Acidic Ph ◽  
Thick Filaments ◽  
Low Ionic Strength

At low ionic strength, Acanthamoeba myosin-II polymerizes into bipolar minifilaments, consisting of eight molecules, that scatter about three times as much light as monomers. With this light scattering assay, we show that the critical concentration for assembly in 50-mM KCl is less than 5 nM. Phosphorylation of the myosin heavy chain over the range of 0.7 to 3.7 P per molecule has no effect on its KCl dependent assembly properties: the structure of the filaments, the extent of assembly, and the critical concentration for assembly are the same. Sucrose at a concentration above a few percent inhibits polymerization. Millimolar concentrations of MgCl2 induce the lateral aggregation of fully formed minifilaments into thick filaments. Compared with dephosphorylated minifilaments, minifilaments of phosphorylated myosin have a lower tendency to aggregate laterally and require higher concentrations of MgCl2 for maximal light scattering. Acidic pH also induces lateral aggregation, whereas basic pH leads to depolymerization of the myosin-II minifilaments. Under polymerizing conditions, millimolar concentrations of ATP only slightly decrease the light scattering of either phosphorylated or dephosphorylated myosin-II. Barring further modulation of assembly by unknown proteins, both phosphorylated and dephosphorylated myosin-II are expected to be in the form of minifilaments under the ionic conditions existing within Acanthamoeba.

scholarly journals Structural Changes in the Thick Filaments during Activation of Demembranated Skeletal Muscle Fibers

2017 ◽  
Vol 112 (3) ◽  
pp. 181a ◽  
Author(s):  
Marco Caremani ◽  
Luca Fusi ◽  
Massimo Reconditi ◽  
Gabriella Piazzesi ◽  
Theyencheri Narayanan ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Structural Changes ◽  
Muscle Fibers ◽  
Thick Filaments ◽  
Skeletal Muscle Fibers

scholarly journals Characterization of components of Z-bands in the fibrillar flight muscle of Drosophila melanogaster.

1989 ◽  
Vol 109 (5) ◽  
pp. 2157-2167 ◽  
Author(s):  
J D Saide ◽  
S Chin-Bow ◽  
J Hogan-Sheldon ◽  
L Busquets-Turner ◽  
J O Vigoreaux ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Monoclonal Antibodies ◽  
Flight Muscle ◽  
Cross Reactivity ◽  
Antigenic Determinants ◽  
Immunogold Staining ◽  
Thick Filaments ◽  
The Matrix ◽  
Flight Muscles

Twelve monoclonal antibodies have been raised against proteins in preparations of Z-disks isolated from Drosophila melanogaster flight muscle. The monoclonal antibodies that recognized Z-band components were identified by immunofluorescence microscopy of flight muscle myofibrils. These antibodies have identified three Z-disk antigens on immunoblots of myofibrillar proteins. Monoclonal antibodies alpha:1-4 recognize a 90-100-kD protein which we identify as alpha-actinin on the basis of cross-reactivity with antibodies raised against honeybee and vertebrate alpha-actinins. Monoclonal antibodies P:1-4 bind to the high molecular mass protein, projectin, a component of connecting filaments that link the ends of thick filaments to the Z-band in insect asynchronous flight muscles. The anti-projectin antibodies also stain synchronous muscle, but, surprisingly, the epitopes here are within the A-bands, not between the A- and Z-bands, as in flight muscle. Monoclonal antibodies Z(210):1-4 recognize a 210-kD protein that has not been previously shown to be a Z-band structural component. A fourth antigen, resolved as a doublet (approximately 400/600 kD) on immunoblots of Drosophila fibrillar proteins, is detected by a cross reacting antibody, Z(400):2, raised against a protein in isolated honeybee Z-disks. On Lowicryl sections of asynchronous flight muscle, indirect immunogold staining has localized alpha-actinin and the 210-kD protein throughout the matrix of the Z-band, projectin between the Z- and A-bands, and the 400/600-kD components at the I-band/Z-band junction. Drosophila alpha-actinin, projectin, and the 400/600-kD components share some antigenic determinants with corresponding honeybee proteins, but no honeybee protein interacts with any of the Z(210) antibodies.

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