scholarly journals A Conserved LIM Protein That Affects Muscular Adherens Junction Integrity and Mechanosensory Function in Caenorhabditis elegans

1999 ◽  
Vol 144 (1) ◽  
pp. 45-57 ◽  
Author(s):  
Oliver Hobert ◽  
Donald G. Moerman ◽  
Kathleen A. Clark ◽  
Mary C. Beckerle ◽  
Gary Ruvkun
Keyword(s):  
Caenorhabditis Elegans ◽  
Body Wall ◽  
Structural Integrity ◽  
Adherens Junctions ◽  
Functional Characterization ◽  
Adherens Junction ◽  
Cell Types ◽  
Loss Of Function ◽  
Body Wall Muscles ◽  
Lim Proteins

We describe here the molecular and functional characterization of the Caenorhabditis elegans unc-97 gene, whose gene product constitutes a novel component of muscular adherens junctions. UNC-97 and homologues from several other species define the PINCH family, a family of LIM proteins whose modular composition of five LIM domains implicates them as potential adapter molecules. unc-97 expression is restricted to tissue types that attach to the hypodermis, specifically body wall muscles, vulval muscles, and mechanosensory neurons. In body wall muscles, the UNC-97 protein colocalizes with the β-integrin PAT-3 to the focal adhesion-like attachment sites of muscles. Partial and complete loss-of-function studies demonstrate that UNC-97 affects the structural integrity of the integrin containing muscle adherens junctions and contributes to the mechanosensory functions of touch neurons. The expression of a Drosophila homologue of unc-97 in two integrin containing cell types, muscles, and muscle-attached epidermal cells, suggests that unc-97 function in adherens junction assembly and stability has been conserved across phylogeny. In addition to its localization to adherens junctions UNC-97 can also be detected in the nucleus, suggesting multiple functions for this LIM domain protein.

par-4, a gene required for cytoplasmic localization and determination of specific cell types in Caenorhabditis elegans embryogenesis.

Genetics ◽  
1992 ◽  
Vol 130 (4) ◽  
pp. 771-790 ◽  
Author(s):  
D G Morton ◽  
J M Roos ◽  
K J Kemphues
Keyword(s):  
Caenorhabditis Elegans ◽  
Cell Types ◽  
Intestinal Cells ◽  
Specific Cell ◽  
Cytoplasmic Localization ◽  
Loss Of Function ◽  
Embryo Viability ◽  
Cell Stage ◽  
Maternal Genome

Abstract Specification of some cell fates in the early Caenorhabditis elegans embryo is mediated by cytoplasmic localization under control of the maternal genome. Using nine newly isolated mutations, and two existing mutations, we have analyzed the role of the maternally expressed gene par-4 in cytoplasmic localization. We recovered seven new par-4 alleles in screens for maternal effect lethal mutations that result in failure to differentiate intestinal cells. Two additional par-4 mutations were identified in noncomplementation screens using strains with a high frequency of transposon mobility. All 11 mutations cause defects early in development of embryos produced by homozygous mutant mothers. Analysis with a deficiency in the region indicates that it33 is a strong loss-of-function mutation. par-4(it33) terminal stage embryos contain many cells, but show no morphogenesis, and are lacking intestinal cells. Temperature shifts with the it57ts allele suggest that the critical period for both intestinal differentiation and embryo viability begins during oogenesis, about 1.5 hr before fertilization, and ends before the four-cell stage. We propose that the primary function of the par-4 gene is to act as part of a maternally encoded system for cytoplasmic localization in the first cell cycle, with par-4 playing a particularly important role in the determination of intestine. Analysis of a par-4; par-2 double mutant suggests that par-4 and par-2 gene products interact in this system.

scholarly journals A nervous system-specific subnuclear organelle in Caenorhabditis elegans

Genetics ◽  
2021 ◽  
Vol 217 (1) ◽  
Author(s):  
Kenneth Pham ◽  
Neda Masoudi ◽  
Eduardo Leyva-Díaz ◽  
Oliver Hobert
Keyword(s):  
Nervous System ◽  
Caenorhabditis Elegans ◽  
Homeobox Gene ◽  
Cell Types ◽  
Nuclear Bodies ◽  
Loss Of Function ◽  
Cell Type ◽  
Cell Type Specificity ◽  
Splicing Speckles ◽  
Polycomb Bodies

Abstract We describe here phase-separated subnuclear organelles in the nematode Caenorhabditis elegans, which we term NUN (NUclear Nervous system-specific) bodies. Unlike other previously described subnuclear organelles, NUN bodies are highly cell type specific. In fully mature animals, 4–10 NUN bodies are observed exclusively in the nucleus of neuronal, glial and neuron-like cells, but not in other somatic cell types. Based on co-localization and genetic loss of function studies, NUN bodies are not related to other previously described subnuclear organelles, such as nucleoli, splicing speckles, paraspeckles, Polycomb bodies, promyelocytic leukemia bodies, gems, stress-induced nuclear bodies, or clastosomes. NUN bodies form immediately after cell cycle exit, before other signs of overt neuronal differentiation and are unaffected by the genetic elimination of transcription factors that control many other aspects of neuronal identity. In one unusual neuron class, the canal-associated neurons, NUN bodies remodel during larval development, and this remodeling depends on the Prd-type homeobox gene ceh-10. In conclusion, we have characterized here a novel subnuclear organelle whose cell type specificity poses the intriguing question of what biochemical process in the nucleus makes all nervous system-associated cells different from cells outside the nervous system.

scholarly journals Golgi spectrin: identification of an erythroid beta-spectrin homolog associated with the Golgi complex.

1994 ◽  
Vol 127 (3) ◽  
pp. 707-723 ◽  
Author(s):  
K A Beck ◽  
J A Buchanan ◽  
V Malhotra ◽  
W J Nelson
Keyword(s):  
Golgi Complex ◽  
Structural Integrity ◽  
Functional Organization ◽  
Brefeldin A ◽  
Cell Types ◽  
Loss Of Function ◽  
Dynamic Relationship ◽  
Golgi Membranes ◽  
Golgi Structure ◽  
And Function

Spectrin is a major component of a membrane-associated cytoskeleton involved in the maintenance of membrane structural integrity and the generation of functionally distinct membrane protein domains. Here, we show that a homolog of erythrocyte beta-spectrin (beta I sigma*) co-localizes with markers of the Golgi complex in a variety of cell types, and that microinjected beta-spectrin codistributes with elements of the Golgi complex. Significantly, we show a dynamic relationship between beta-spectrin and the structural and functional organization of the Golgi complex. Disruption of both Golgi structure and function, either in mitotic cells or following addition of brefeldin A, is accompanied by loss of beta-spectrin from Golgi membranes and dispersal in the cytoplasm. In contrast, perturbation of Golgi structure without a loss of function, by the addition of nocodazole, results in retention of beta-spectrin with the dispersed Golgi elements. These results indicate that the association of beta-spectrin with Golgi membranes is coupled to Golgi organization and function.

scholarly journals Immunochemical localization of myosin heavy chain isoforms and paramyosin in developmentally and structurally diverse muscle cell types of the nematode Caenorhabditis elegans.

1987 ◽  
Vol 105 (6) ◽  
pp. 2763-2770 ◽  
Author(s):  
J P Ardizzi ◽  
H F Epstein
Keyword(s):  
Caenorhabditis Elegans ◽  
Muscle Cell ◽  
Body Wall ◽  
Muscle Cells ◽  
Cell Types ◽  
The Body ◽  
Myosin Heavy Chains ◽  
Nematode Caenorhabditis Elegans ◽  
Heavy Chains ◽  
Pharyngeal Muscles

The nematode Caenorhabditis elegans contains two major groups of muscle cells that exhibit organized sarcomeres: the body wall and pharyngeal muscles. Several additional groups of muscle cells of more limited mass and spatial distribution include the vulval muscles of hermaphrodites, the male sex muscles, the anal-intestinal muscles, and the gonadal sheath of the hermaphrodite. These muscle groups do not exhibit sarcomeres and therefore may be considered smooth. Each muscle cell has been shown to have a specific origin in embryonic cell lineages and differentiation, either embryonically or postembryonically (Sulston, J. E., and H. R. Horvitz. 1977. Dev. Biol. 56:110-156; Sulston, J. E., E. Schierenberg, J. White, and J. N. Thomson. 1983. Dev. Biol. 100:64-119). Each muscle type exhibits a unique combination of lineage and onset of differentiation at the cellular level. Biochemically characterized monoclonal antibodies to myosin heavy chains A, B, C, and D and to paramyosin have been used in immunochemical localization experiments. Paramyosin is detected by immunofluorescence in all muscle cells. Myosin heavy chains C and D are limited to the pharyngeal muscle cells, whereas myosin heavy chains A and B are localized not only within the sarcomeres of body wall muscle cells, as reported previously, but to the smooth muscle cells of the minor groups as well. Myosin heavy chains A and B and paramyosin proteins appear to be compatible with functionally and structurally distinct muscle cell types that arise by multiple developmental pathways.

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.

scholarly journals Optical silencing of body wall muscles induces pumping inhibition in Caenorhabditis elegans

PLoS Genetics ◽  
2017 ◽  
Vol 13 (12) ◽  
pp. e1007134 ◽  
Author(s):  
Megumi Takahashi ◽  
Shin Takagi
Keyword(s):  
Caenorhabditis Elegans ◽  
Body Wall ◽  
Body Wall Muscles

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 Muscle cell attachment in Caenorhabditis elegans.

1991 ◽  
Vol 114 (3) ◽  
pp. 465-479 ◽  
Author(s):  
R Francis ◽  
R H Waterston
Keyword(s):  
Caenorhabditis Elegans ◽  
Basement Membrane ◽  
Muscle Cell ◽  
Body Wall ◽  
Cell Attachment ◽  
Muscle Cells ◽  
The Body ◽  
Nematode Caenorhabditis Elegans ◽  
Hypodermal Cell ◽  
Body Wall Muscles

In the nematode Caenorhabditis elegans, the body wall muscles exert their force on the cuticle to generate locomotion. Interposed between the muscle cells and the cuticle are a basement membrane and a thin hypodermal cell. The latter contains bundles of filaments attached to dense plaques in the hypodermal cell membranes, which together we have called a fibrous organelle. In an effort to define the chain of molecules that anchor the muscle cells to the cuticle we have isolated five mAbs using preparations enriched in these components. Two antibodies define a 200-kD muscle antigen likely to be part of the basement membrane at the muscle/hypodermal interface. Three other antibodies probably identify elements of the fibrous organelles in the adjacent hypodermis. The mAb IFA, which reacts with mammalian intermediate filaments, also recognizes these structures. We suggest that the components recognized by these antibodies are likely to be involved in the transmission of tension from the muscle cell to the cuticle.

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