scholarly journals Z-line formins promote contractile lattice growth and maintenance in striated muscles of C. elegans

2012 ◽  
Vol 198 (1) ◽  
pp. 87-102 ◽  
Author(s):  
Lei Mi-Mi ◽  
SarahBeth Votra ◽  
Kenneth Kemphues ◽  
Anthony Bretscher ◽  
David Pruyne
Keyword(s):  
Actin Filaments ◽  
Body Wall ◽  
Striated Muscles ◽  
Filamentous Actin ◽  
Simultaneous Reduction ◽  
Stunted Growth ◽  
C Elegans ◽  
Myosin Filaments ◽  
Body Wall Muscles

Muscle contraction depends on interactions between actin and myosin filaments organized into sarcomeres, but the mechanism by which actin filaments incorporate into sarcomeres remains unclear. We have found that, during larval development in Caenorhabditis elegans, two members of the actin-assembling formin family, CYK-1 and FHOD-1, are present in striated body wall muscles near or on sarcomere Z lines, where barbed ends of actin filaments are anchored. Depletion of either formin during this period stunted growth of the striated contractile lattice, whereas their simultaneous reduction profoundly diminished lattice size and number of striations per muscle cell. CYK-1 persisted at Z lines in adulthood, and its near complete depletion from adults triggered phenotypes ranging from partial loss of Z line–associated filamentous actin to collapse of the contractile lattice. These results are, to our knowledge, the first genetic evidence implicating sarcomere-associated formins in the in vivo organization of the muscle cytoskeleton.

Calsequestrin, a calcium sequestering protein localized at the sarcoplasmic reticulum, is not essential for body-wall muscle function in Caenorhabditis elegans

2000 ◽  
Vol 113 (22) ◽  
pp. 3947-3958 ◽  
Author(s):  
J.H. Cho ◽  
Y.S. Oh ◽  
K.W. Park ◽  
J. Yu ◽  
K.Y. Choi ◽  
...  
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Calcium Binding ◽  
Body Wall ◽  
Functional Characterization ◽  
The Body ◽  
Body Wall Muscle ◽  
C Elegans ◽  
Muscle Formation ◽  
Body Wall Muscles

Calsequestrin is the major calcium-binding protein of cardiac and skeletal muscles whose function is to sequester Ca(2+)in the lumen of the sarcoplasmic reticulum (SR). Here we describe the identification and functional characterization of a C. elegans calsequestrin gene (csq-1). CSQ-1 shows moderate similarity (50% similarity, 30% identity) to rabbit skeletal calsequestrin. Unlike mammals, which have two different genes encoding cardiac and fast-twitch skeletal muscle isoforms, csq-1 is the only calsequestrin gene in the C. elegans genome. We show that csq-1 is highly expressed in the body-wall muscles, beginning in mid-embryogenesis and maintained through the adult stage. In body-wall muscle cells, CSQ-1 is localized to sarcoplasmic membranes surrounding sarcomeric structures, in the regions where ryanodine receptors (UNC-68) are located. Mutation in UNC-68 affects CSQ-1 localization, suggesting that the two possibly interact in vivo. Genetic analyses of chromosomal deficiency mutants deleting csq-1 show that CSQ-1 is not essential for initiation of embryonic muscle formation and contraction. Furthermore, double-stranded RNA injection resulted in animals completely lacking CSQ-1 in body-wall muscles with no observable defects in locomotion. These findings suggest that although CSQ-1 is one of the major calcium-binding proteins in the body-wall muscles of C. elegans, it is not essential for body-wall muscle formation and contraction.

In Vivo Calcium Imaging in C. elegans Body Wall Muscles

10.3791/59175 ◽  
2019 ◽  
Author(s):  
Ashley A. Martin ◽  
Simon Alford ◽  
Janet E. Richmond
Keyword(s):  
Calcium Imaging ◽  
Body Wall ◽  
C Elegans ◽  
Body Wall Muscles ◽  
In Vivo Calcium Imaging

Positioning and maintenance of embryonic body wall muscle attachments in C. elegans requires the mup-1 gene

Development ◽  
1991 ◽  
Vol 111 (3) ◽  
pp. 667-681 ◽  
Author(s):  
P.Y. Goh ◽  
T. Bogaert
Keyword(s):  
Extracellular Matrix ◽  
Body Wall ◽  
Early Stage ◽  
Muscle Growth ◽  
The Body ◽  
Body Wall Muscle ◽  
C Elegans ◽  
Extracellular Matrix Molecule ◽  
Extracellular Matrix Components ◽  
Body Wall Muscles

As part of a general study of genes specifying a pattern of muscle attachments, we identified and genetically characterised mutants in the mup-1 gene. The body wall muscles of early stage mup-1 embryos have a wild-type myofilament pattern but may extend ectopic processes. Later in embryogenesis, some body wall muscles detach from the hypodermis. Genetic analysis suggests that mup-1 has both a maternal and a zygotic component and is not required for postembryonic muscle growth and attachment. mup-1 mutants are suppressed by mutations in several genes that encode extracellular matrix components. We propose that mup-1 may encode a cell surface/extracellular matrix molecule required both for the positioning of body wall muscle attachments in early embryogenesis and the subsequent maintenance of these attachments to the hypodermis until after cuticle synthesis.

Paramyosin isoforms of Schistosoma mansoni are phosphorylated and localized in a large variety of muscle types

Parasitology ◽  
1996 ◽  
Vol 112 (5) ◽  
pp. 459-467 ◽  
Author(s):  
J. Schmidt ◽  
O. Bodor ◽  
L. Gohr ◽  
W. Kunz
Keyword(s):  
Schistosoma Mansoni ◽  
Specific Antibody ◽  
Body Wall ◽  
Uranyl Acetate ◽  
The Body ◽  
Striated Muscles ◽  
Western Blots ◽  
Muscle Types ◽  
Longitudinal Muscles

SUMMARYParamyosin, although a widely distributed muscle component among invertebrates, has hitherto not clearly been shown to occur in the muscles of schistosomes. Instead, it has been reported to occur in the tegument. In the present study, a specific antibody reacting with each of 10 isoforms of paramyosin was used for light microscopical immunolocalization in sections of Schistosoma mansoni. Specimens were fixed by a new method to immobilize antigens with uranyl acetate–trehalose–methanol. In cercariae, schistosomula, and adults, the circular and longitudinal muscles of the body wall, the dorsoventral muscles and those surrounding the gut and the pharynx as well as the fast moving cross-striated muscles of the tail of cercariae intensely reacted with the antibody. However, neither immunohistologically nor on Western blots of isolated tegument, were indications found for the presence of paramyosin in the tegument. In vivo phosphorylation and binding of anti-phospho-tyrosine and anti-phospho-serine antibodies show phosphorylation of paramyosin which probably is responsible for the generation of the isoforms.

scholarly journals Overexpression of cofilin stimulates bundling of actin filaments, membrane ruffling, and cell movement in Dictyostelium.

1996 ◽  
Vol 132 (3) ◽  
pp. 335-344 ◽  
Author(s):  
H Aizawa ◽  
K Sutoh ◽  
I Yahara
Keyword(s):  
Actin Filaments ◽  
Cell Movement ◽  
Structure And Function ◽  
Cross Linking ◽  
Low Molecular Weight ◽  
Filamentous Actin ◽  
Membrane Ruffling ◽  
And Function

Cofilin is a low molecular weight actin-modulating protein whose structure and function are conserved among eucaryotes. Cofilin exhibits in vitro both a monomeric actin-sequestering activity and a filamentous actin-severing activity. To investigate in vivo functions of cofilin, cofilin was overexpressed in Dictyostelium discoideum cells. An increase in the content of D. discoideum cofilin (d-cofilin) by sevenfold induced a co-overproduction of actin by threefold. In cells over-expressing d-cofilin, the amount of filamentous actin but not that of monomeric actin was increased. Overexpressed d-cofilin co-sedimented with actin filaments, suggesting that the sequestering activity of d-cofilin is weak in vivo. The overexpression of d-cofilin increased actin bundles just beneath ruffling membranes where d-cofilin was co-localized. The overexpression of d-cofilin also stimulated cell movement as well as membrane ruffling. We have demonstrated in vitro that d-cofilin transformed latticework of actin filaments cross-linked by alpha-actinin into bundles probably by severing the filaments. D. discoideum cofilin may sever actin filaments in vivo and induce bundling of the filaments in the presence of cross-linking proteins so as to generate contractile systems involved in membrane ruffling and cell movement.

scholarly journals Inhibition underlies fast undulatory locomotion in C. elegans

2020 ◽  
Author(s):  
Lan Deng ◽  
Jack Denham ◽  
Charu Arya ◽  
Omer Yuval ◽  
Netta Cohen ◽  
...  
Keyword(s):  
Computational Models ◽  
Body Wall ◽  
Activity Patterns ◽  
Wild Type ◽  
C Elegans ◽  
Body Wall Muscles ◽  
Undulatory Locomotion ◽  
Gaba Transmission ◽  
Cross Inhibition

AbstractInhibition plays important roles in modulating the neural activities of sensory and motor systems at different levels from synapses to brain regions. To achieve coordinated movement, motor systems produce alternating contraction of antagonist muscles, whether along the body axis or within and among limbs. In the nematode C. elegans, a small network involving excitatory cholinergic and inhibitory GABAergic motoneurons generates the dorsoventral alternation of body-wall muscles that supports undulatory locomotion. Inhibition has been suggested to be necessary for backward undulation because mutants that are defective in GABA transmission exhibit a shrinking phenotype in response to a harsh touch to the head, whereas wild-type animals produce a backward escape response. Here, we demonstrate that the shrinking phenotype is exhibited by wild-type as well as mutant animals in response to harsh touch to the head or tail, but only GABA transmission mutants show slow locomotion after stimulation. Impairment of GABA transmission, either genetically or optogenetically, induces lower undulation frequency and lower translocation speed during crawling and swimming in both directions. The activity patterns of GABAergic motoneurons are different during low and high undulation frequencies. During low undulation frequency, GABAergic VD and DD motoneurons show similar activity patterns, while during high undulation frequency, their activity alternates. The experimental results suggest at least three non-mutually exclusive roles for inhibition that could underlie fast undulatory locomotion in C. elegans, which we tested with computational models: cross-inhibition or disinhibition of body-wall muscles, or inhibitory reset.Significance StatementInhibition serves multiple roles in the generation, maintenance, and modulation of the locomotive program and supports the alternating activation of antagonistic muscles. When the locomotor frequency increases, more inhibition is required. To better understand the role of inhibition in locomotion, we used C. elegans as an animal model, and challenged a prevalent hypothesis that cross-inhibition supports the dorsoventral alternation. We find that inhibition is related to the speed rather than the direction of locomotion and demonstrate that inhibition is unnecessary for muscle alternation during slow undulation in either direction but crucial to sustain rapid dorsoventral alternation. We combined calcium imaging of motoneurons and muscle with computational models to test hypotheses for the role of inhibition in locomotion.

scholarly journals ROCK-I regulates closure of the eyelids and ventral body wall by inducing assembly of actomyosin bundles

2005 ◽  
Vol 168 (6) ◽  
pp. 941-953 ◽  
Author(s):  
Yoshihiko Shimizu ◽  
Dean Thumkeo ◽  
Jeongsin Keel ◽  
Toshimasa Ishizaki ◽  
Hiroko Oshima ◽  
...  
Keyword(s):  
Body Wall ◽  
Fiber Formation ◽  
Filamentous Actin ◽  
Primary Keratinocytes ◽  
Eyelid Closure ◽  
Eyes Open ◽  
Actin Cables ◽  
Mlc Phosphorylation ◽  
Deficient Mice

Rho-associated kinase (ROCK) I mediates signaling from Rho to the actin cytoskeleton. To investigate the in vivo functions of ROCK-I, we generated ROCK-I–deficient mice. Loss of ROCK-I resulted in failure of eyelid closure and closure of the ventral body wall, which gave rise to the eyes open at birth and omphalocele phenotypes in neonates. Most ROCK-I−/− mice died soon after birth as a result of cannibalization of the omphalocele by the mother. Actin cables that encircle the eye in the epithelial cells of the eyelid were disorganized and accumulation of filamentous actin at the umbilical ring was impaired, with loss of phosphorylation of the myosin regulatory light chain (MLC) at both sites, in ROCK-I−/− embryos. Stress fiber formation and MLC phosphorylation induced by EGF were also attenuated in primary keratinocytes from ROCK-I−/− mice. These results suggest that ROCK-I regulates closure of the eyelids and ventral body wall through organization of actomyosin bundles.

Polarization dependant in vivo second harmonic generation imaging of Caenorhabditis elegans vulval, pharynx, and body wall muscles

2008 ◽  
Author(s):  
Sotiris Psilodimitrakopoulos ◽  
Susana Santos ◽  
Ivan Amat-Roldan ◽  
Manoj Mathew ◽  
Anisha Thayil K. N. ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Second Harmonic Generation ◽  
Harmonic Generation ◽  
Body Wall ◽  
Second Harmonic ◽  
Body Wall Muscles ◽  
Second Harmonic Generation Imaging

scholarly journals Purified thick filaments from the nematode Caenorhabditis elegans: evidence for multiple proteins associated with core structures.

1988 ◽  
Vol 106 (6) ◽  
pp. 1985-1995 ◽  
Author(s):  
H F Epstein ◽  
G C Berliner ◽  
D L Casey ◽  
I Ortiz
Keyword(s):  
Caenorhabditis Elegans ◽  
Body Wall ◽  
Gradient Centrifugation ◽  
Blue Staining ◽  
Nematode Caenorhabditis Elegans ◽  
C Elegans ◽  
Thick Filaments ◽  
Cell Biol ◽  
Associated Proteins ◽  
Body Wall Muscles

The thick filaments of the nematode, Caenorhabditis elegans, arising predominantly from the body-wall muscles, contain two myosin isoforms and paramyosin as their major proteins. The two myosins are located in distinct regions of the surfaces, while paramyosin is located within the backbones of the filaments. Tubular structures constitute the cores of the polar regions, and electron-dense material is present in the cores of the central regions (Epstein, H.F., D.M. Miller, I. Ortiz, and G.C. Berliner. 1985. J. Cell Biol. 100:904-915). Biochemical, genetic, and immunological experiments indicate that the two myosins and paramyosin are not necessary core components (Epstein, H.F., I. Ortiz, and L.A. Traeger Mackinnon. 1986. J. Cell Biol. 103:985-993). The existence of the core structures suggests, therefore, that additional proteins may be associated with thick filaments in C. elegans. To biochemically detect minor associated proteins, a new procedure for the isolation of thick filaments of high purity and structural preservation has been developed. The final step, glycerol gradient centrifugation, yielded fractions that are contaminated by, at most, 1-2% with actin, tropomyosin, or ribosome-associated proteins on the basis of Coomassie Blue staining and electron microscopy. Silver staining and radioautography of gel electrophoretograms of unlabeled and 35S-labeled proteins, respectively, revealed at least 10 additional bands that cosedimented with thick filaments in glycerol gradients. Core structures prepared from wild-type thick filaments contained at least six of these thick filament-associated protein bands. The six proteins also cosedimented with thick filaments purified by gradient centrifugation from CB190 mutants lacking myosin heavy chain B and from CB1214 mutants lacking paramyosin. For these reasons, we propose that the six associated proteins are potential candidates for putative components of core structures in the thick filaments of body-wall muscles of C. elegans.

scholarly journals An invertebrate smooth muscle with striated muscle myosin filaments

2015 ◽  
Vol 112 (42) ◽  
pp. E5660-E5668 ◽  
Author(s):  
Guidenn Sulbarán ◽  
Lorenzo Alamo ◽  
Antonio Pinto ◽  
Gustavo Márquez ◽  
Franklin Méndez ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Actin Filaments ◽  
Striated Muscle ◽  
Smooth Muscles ◽  
Structural Similarity ◽  
Striated Muscles ◽  
Muscle Tissues ◽  
Myosin Filaments ◽  
Muscle Myosin ◽  
Surprising Finding

Muscle tissues are classically divided into two major types, depending on the presence or absence of striations. In striated muscles, the actin filaments are anchored at Z-lines and the myosin and actin filaments are in register, whereas in smooth muscles, the actin filaments are attached to dense bodies and the myosin and actin filaments are out of register. The structure of the filaments in smooth muscles is also different from that in striated muscles. Here we have studied the structure of myosin filaments from the smooth muscles of the human parasite Schistosoma mansoni. We find, surprisingly, that they are indistinguishable from those in an arthropod striated muscle. This structural similarity is supported by sequence comparison between the schistosome myosin II heavy chain and known striated muscle myosins. In contrast, the actin filaments of schistosomes are similar to those of smooth muscles, lacking troponin-dependent regulation. We conclude that schistosome muscles are hybrids, containing striated muscle-like myosin filaments and smooth muscle-like actin filaments in a smooth muscle architecture. This surprising finding has broad significance for understanding how muscles are built and how they evolved, and challenges the paradigm that smooth and striated muscles always have distinctly different components.

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