scholarly journals Loss of Dystrobrevin Causes Muscle Degeneration and a Short Lifespan in Caenorhabditis elegans

2017 ◽  
Vol 15 (9) ◽  
pp. 659-667
Author(s):  
Worawit SUPHAMUNGMEE ◽  
Prapaporn JATTUJAN ◽  
Krai MEEMON
Keyword(s):  
Protein Complexes ◽  
The Body ◽  
Muscle Degeneration ◽  
Cell Integrity ◽  
Wild Type ◽  
C Elegans ◽  
Short Lifespan ◽  
C Terminus ◽  
Cell Stability

Duchene’s muscular dystrophy (DMD) is an inherited disorder in an X-linked recessive manner. Lack of dystrophin causes progressive muscle degeneration. Dystrophin structurally connects to actin filaments at the N-terminus while the C-terminus interacts with an integral domain of the dystroglycan complex. Among the associated molecules, dystrobrevin acts as a modulator protein exerting dystrophin's function for strengthening the cell stability. Previous data has reported the delayed muscle degeneration following an overexpression of the dystrobrevin (dyb) gene in the DMD-phenotype C. elegans, whose dystrophin (dys) gene was missing. This finding indicates the role of a modulator protein, rather than dystrophin, to maintain the cell integrity. The present study aims to investigate the phenotypes of C. elegans, due to dyb- or dys-deficiency. When compared with the wild-type, the dyb-deficient worms exhibited uncoordinated locomotion and lysis of the muscular layer in the body wall and internal organs as well as those observed in the dys-deficient worms. The ultrastructure of both mutant worms appeared severe muscle degeneration, decrease of the mitochondria, and replacement of fibrotic tissue, particularly the dys-mutant which was even more severe. Additionally, a shorter lifespan was observed with a 17 % reduction (p < 0.05) in dyb-deficient worms and 27 % reduction (p < 0.05) in dys-deficient worms when compared to wild-type. It is speculated that dystrobrevin may stabilize the cell through interaction with other protein complexes at the plasma membrane while it also binds to dystrophin. Therefore, the loss of dystrobrevin is also sufficient to disrupt the signaling pathway and causes muscle degeneration.

scholarly journals A CACNA1A variant associated with trigeminal neuralgia alters the gating of Cav2.1 channels

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Eder Gambeta ◽  
Maria A. Gandini ◽  
Ivana A. Souza ◽  
Laurent Ferron ◽  
Gerald W. Zamponi
Keyword(s):  
Trigeminal Neuralgia ◽  
Missense Mutation ◽  
Neurotransmitter Release ◽  
Trigeminal System ◽  
Wild Type ◽  
Calcium Dependent ◽  
Whole Cell Patch Clamp ◽  
C Terminus ◽  
Dependent Inactivation

AbstractA novel missense mutation in the CACNA1A gene that encodes the pore forming α1 subunit of the CaV2.1 voltage-gated calcium channel was identified in a patient with trigeminal neuralgia. This mutation leads to a substitution of proline 2455 by histidine (P2455H) in the distal C-terminus region of the channel. Due to the well characterized role of this channel in neurotransmitter release, our aim was to characterize the biophysical properties of the P2455H variant in heterologously expressed CaV2.1 channels. Whole-cell patch clamp recordings of wild type and mutant CaV2.1 channels expressed in tsA-201 cells reveal that the mutation mediates a depolarizing shift in the voltage-dependence of activation and inactivation. Moreover, the P2455H mutant strongly reduced calcium-dependent inactivation of the channel that is consistent with an overall gain of function. Hence, the P2455H CaV2.1 missense mutation alters the gating properties of the channel, suggesting that associated changes in CaV2.1-dependent synaptic communication in the trigeminal system may contribute to the development of trigeminal neuralgia.

Touch insensitive foraging of Caenorhabditis elegans in a constrained structure

Nematology ◽  
2009 ◽  
Vol 11 (4) ◽  
pp. 551-554
Author(s):  
Jinu Eo ◽  
Kazunori Otobe
Keyword(s):  
Caenorhabditis Elegans ◽  
Natural Habitat ◽  
The Body ◽  
Wild Type ◽  
Agar Gel ◽  
Touch Sensor ◽  
Foraging Pattern

Abstract The objective of this study was to clarify the role of touch sensors in the foraging of Caenorhabditis elegans in a constrained structure. The strains tested included an array of mechanosensory mutants insensitive to touch in the body, tail or nose. The mutants and wild type nematodes repeated forward and backward movement in a micro-moulded substrate as on the surface of agar gel. Differences in the foraging pattern were not obvious among mutant groups having different touch sensor deficit in the substrate, and all strains of nematode successfully moved out of the T-shaped structure after searching the configuration of their environment. The results suggest that the touch sensor is a weak contributor to the performance of the worms when foraging, and the behaviour is governed by intrinsic spontaneous patterns in the absence of any stimuli in natural habitat.

scholarly journals The double-stranded DNA-binding proteins TEBP-1 and TEBP-2 form a telomeric complex with POT-1

2020 ◽  
Author(s):  
Sabrina Dietz ◽  
Miguel Vasconcelos Almeida ◽  
Emily Nischwitz ◽  
Jan Schreier ◽  
Nikenza Viceconte ◽  
...  
Keyword(s):  
Quantitative Proteomics ◽  
Binding Proteins ◽  
Protein Complexes ◽  
Wild Type ◽  
C Elegans ◽  
Double Stranded Dna ◽  
Telomere Sequence ◽  
Proteomics Approach

AbstractTelomeres are bound by dedicated protein complexes, like shelterin in mammals, which protect telomeres from DNA damage. In the nematode Caenorhabditis elegans, a comprehensive understanding of the proteins interacting with the telomere sequence is lacking. Here, we harnessed a quantitative proteomics approach to screen for proteins binding to C. elegans telomeres, and identified TEBP-1 and TEBP-2, two paralogs that associate to telomeres in vitro and in vivo. TEBP-1 and TEBP-2 are expressed in the germline and during embryogenesis. tebp-1 and tebp-2 mutants display strikingly distinct phenotypes: tebp-1 mutants have longer telomeres than wild-type animals, while tebp-2 mutants display shorter telomeres and a mortal germline, a phenotype characterized by transgenerational germline deterioration. Notably, tebp-1; tebp-2 double mutant animals have synthetic sterility, with germlines showing signs of severe mitotic and meiotic arrest. TEBP-1 and TEBP-2 form a telomeric complex with the known single-stranded telomere-binding proteins POT-1, POT-2, and MRT-1. Furthermore, we find that POT-1 bridges the double- stranded binders TEBP-1 and TEBP-2, with the single-stranded binders POT-2 and MRT-1. These results describe the first telomere-binding complex in C. elegans, with TEBP-1 and TEBP-2, two double-stranded telomere binders required for fertility and that mediate opposite telomere dynamics.

Purification and physical properties of nematode mini-titins and their relation to twitchin

1991 ◽  
Vol 98 (4) ◽  
pp. 491-496
Author(s):  
R. Nave ◽  
D. Furst ◽  
U. Vinkemeier ◽  
K. Weber
Keyword(s):  
Caenorhabditis Elegans ◽  
Immunofluorescence Microscopy ◽  
Apparent Molecular Weight ◽  
The Body ◽  
Wild Type ◽  
Normal Muscle ◽  
Insect Muscle ◽  
C Elegans ◽  
Type C ◽  
Beta Structure

We have isolated mini-titin from the nematodes Ascaris lumbricoides and Caenorhabditis elegans under native conditions using a modification in the procedure to prepare this protein from insect muscle. The proteins have an apparent molecular weight of 600,000 and appear in oriented specimens as flexible thin rods with a length around 240–250 nm. The circular dichroism spectrum of the Ascaris protein is dominated by beta-structure. The proteins react with antibodies to insect mini-titin and also with antibodies raised against peptides contained in the sequence predicted for twitchin, the product of the Caenorhabditis elegans unc-22 gene. Antibodies to insect mini-titin decorate the body musculature as well as the pharynx of wild-type C. elegans in immunofluorescence microscopy. In the twitchin mutant E66 only the pharynx is decorated. We conclude that the mini-titins of invertebrate muscles defined earlier by ultrastructural criteria are very likely to be twitchins, i.e. molecules necessary for normal muscle contraction. We discuss the molecular properties of the proteins in the light of the sequence established for twitchin.

Apical-basal pattern formation in the Arabidopsis embryo: studies on the role of the gnom gene

Development ◽  
1993 ◽  
Vol 117 (1) ◽  
pp. 149-162 ◽  
Author(s):  
U. Mayer ◽  
G. Buttner ◽  
G. Jurgens
Keyword(s):  
Pattern Formation ◽  
Root Formation ◽  
Asymmetric Cell Division ◽  
Early Embryo ◽  
The Body ◽  
Wild Type ◽  
Early Effect ◽  
Normal Number ◽  
Mutant Seedling

gnom is one of several genes that make substantial contributions to pattern formation along the apical-basal axis of polarity in the Arabidopsis embryo as indicated by the mutant seedling phenotype. The apical and basal end regions of the body pattern, which include the meristems of the shoot and the root, fail to form, and a minority of mutant embryos lack morphological features of apical-basal polarity. We have investigated the developmental basis of the gnom mutant phenotype, taking advantage of a large number of EMS-induced mutant alleles. The seedling phenotype has been traced back to the early embryo in which the asymmetric division of the zygote is altered, now producing two nearly equal-sized cells. The apical daughter cell then undergoes abnormal divisions, resulting in an octant embryo with about twice the normal number of cells while the uppermost derivative of the basal cell fails to become the hypophysis, which normally contributes to root development. Consistent with this early effect, gnom appears to be epistatic to monopteros in doubly mutant embryos, suggesting that, without prior gnom activity, the monopteros gene cannot promote root and hypocotyl development. On the other hand, when root formation was induced in bisected seedlings, wild-type responded whereas gnom mutants failed to produce a root but formed callus instead. These results suggest that gnom activity promotes asymmetric cell division which we believe is necessary both for apical-basal pattern formation in the early embryo and for root formation in tissue culture.

scholarly journals LONGEVITY OVER THE COUNTER: INVESTIGATING THE EFFECTS OF COMMON DIETARY SUPPLEMENTS ON AGING

2019 ◽  
Vol 3 (Supplement_1) ◽  
pp. S102-S103
Author(s):  
Ben Blue ◽  
Elena Vayndorf ◽  
Matt Kaeberlein
Keyword(s):  
Body Wall ◽  
Video Recording ◽  
The Body ◽  
Limiting Factor ◽  
Time Of Death ◽  
Image Capture ◽  
Over The Counter ◽  
C Elegans ◽  
Short Lifespan ◽  
Age Related

Abstract C. elegans has been a workhorse within the field of aging biology for several decades due to its short lifespan, easy culturing, and robust genetic tools. However, the limiting factor in using C. elegans has been that throughput was constrained by the time and effort needed to manually check the worms for signs of life during longitudinal studies. By using the WormBot, a robotic image capture platform, we are able to successfully screen a wide array of compounds for their effects upon C. elegans lifespan. A single WormBot can monitor 144 individual experiments simultaneously and allows for accurate time of death calls. Here we present data generated with the WormBot that includes a screen of compounds from a wide array of natural and synthetic products that are often available as over-the-counter supplements. In order to better examine the effects of these widely-used compounds upon the aging process and an age-associated disease we examined longevity in a wildtype strain of C. elegans as well as an engineered strain that expresses human Aβ protein in the body wall muscle. The age-related pathogenesis of the Aβ-expressing strain is a progressive paralysis that can be halted with treatment of known effectors of Alzheimer’s disease. As such, we screened our battery of compounds with this strain to determine which compounds have a significant affect on delaying Aβ-associated paralysis. Lastly, using the WormBot’s ability to capture video recording, we examine how each compound affects mobility as animals age.

scholarly journals Role of the Pilot Protein YscW in the Biogenesis of the YscC Secretin in Yersinia enterocolitica

2004 ◽  
Vol 186 (16) ◽  
pp. 5366-5375 ◽  
Author(s):  
Peter Burghout ◽  
Frank Beckers ◽  
Emmie de Wit ◽  
Ria van Boxtel ◽  
Guy R. Cornelis ◽  
...  
Keyword(s):  
Outer Membrane ◽  
Yersinia Enterocolitica ◽  
Amino Acid Residues ◽  
Wild Type ◽  
C Terminus ◽  
Outer Membrane Lipoprotein ◽  
Protein Secretion System ◽  
Membrane Lipoprotein ◽  
Type Iii Protein Secretion

ABSTRACT The YscC secretin is a major component of the type III protein secretion system of Yersinia enterocolitica and forms an oligomeric structure in the outer membrane. In a mutant lacking the outer membrane lipoprotein YscW, secretion is strongly reduced, and it has been proposed that YscW plays a role in the biogenesis of the secretin. To study the interaction between the secretin and this putative pilot protein, YscC and YscW were produced in trans in a Y. enterocolitica strain lacking all other components of the secretion machinery. YscW expression increased the yield of oligomeric YscC and was required for its outer membrane localization, confirming the function of YscW as a pilot protein. Whereas the pilot-binding site of other members of the secretin family has been identified in the C terminus, a truncated YscC derivative lacking the C-terminal 96 amino acid residues was functional and stabilized by YscW. Pulse-chase experiments revealed that ∼30 min were required before YscC oligomerization was completed. In the absence of YscW, oligomerization was delayed and the yield of YscC oligomers was strongly reduced. An unlipidated form of the YscW protein was not functional, although it still interacted with the secretin and caused mislocalization of YscC even in the presence of wild-type YscW. Hence, YscW interacts with the unassembled YscC protein and facilitates efficient oligomerization, likely at the outer membrane.

scholarly journals Aurora-A kinase is required for centrosome maturation in Caenorhabditis elegans

2001 ◽  
Vol 155 (7) ◽  
pp. 1109-1116 ◽  
Author(s):  
Eva Hannak ◽  
Matthew Kirkham ◽  
Anthony A. Hyman ◽  
Karen Oegema
Keyword(s):  
Caenorhabditis Elegans ◽  
Fluorescence Intensity ◽  
Maturation Process ◽  
Aurora A Kinase ◽  
Aurora A ◽  
Wild Type ◽  
C Elegans ◽  
Nuclear Envelope Breakdown ◽  
Pericentriolar Material

Centrosomes mature as cells enter mitosis, accumulating γ-tubulin and other pericentriolar material (PCM) components. This occurs concomitant with an increase in the number of centrosomally organized microtubules (MTs). Here, we use RNA-mediated interference (RNAi) to examine the role of the aurora-A kinase, AIR-1, during centrosome maturation in Caenorhabditis elegans. In air-1(RNAi) embryos, centrosomes separate normally, an event that occurs before maturation in C. elegans. After nuclear envelope breakdown, the separated centrosomes collapse together, and spindle assembly fails. In mitotic air-1(RNAi) embryos, centrosomal α-tubulin fluorescence intensity accumulates to only 40% of wild-type levels, suggesting a defect in the maturation process. Consistent with this hypothesis, we find that AIR-1 is required for the increase in centrosomal γ-tubulin and two other PCM components, ZYG-9 and CeGrip, as embryos enter mitosis. Furthermore, the AIR-1–dependent increase in centrosomal γ-tubulin does not require MTs. These results suggest that aurora-A kinases are required to execute a MT-independent pathway for the recruitment of PCM during centrosome maturation.

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.

p53 domains: structure, oligomerization, and transformation

1994 ◽  
Vol 14 (8) ◽  
pp. 5182-5191
Author(s):  
P Wang ◽  
M Reed ◽  
Y Wang ◽  
G Mayr ◽  
J E Stenger ◽  
...  
Keyword(s):  
Amino Acids ◽  
Dna Binding ◽  
Gel Filtration ◽  
Dominant Negative ◽  
Wild Type ◽  
C Terminus ◽  
Tetramerization Domain ◽  
Wild Type P53 ◽  
Negative Phenotype

Wild-type p53 forms tetramers and multiples of tetramers. Friedman et al. (P. N. Friedman, X. B. Chen, J. Bargonetti, and C. Prives, Proc. Natl. Acad. Sci. USA 90:3319-3323, 1993) have reported that human p53 behaves as a larger molecule during gel filtration than it does during sucrose gradient sedimentation. These differences argue that wild-type p53 has a nonglobular shape. To identify structural and oligomerization domains in p53, we have investigated the physical properties of purified segments of p53. The central, specific DNA-binding domain within murine amino acids 80 to 320 and human amino acids 83 to 323 behaves predominantly as monomers during analysis by sedimentation, gel filtration, and gel electrophoresis. This consistent behavior argues that the central region of p53 is globular in shape. Under appropriate conditions, however, this segment can form transient oligomers without apparent preference for a single oligomeric structure. This region does not enhance transformation by other oncogenes. The biological implications of transient oligomerization by this central segment, therefore, remain to be demonstrated. Like wild-type p53, the C terminus, consisting of murine amino acids 280 to 390 and human amino acids 283 to 393, behaves anomalously during gel filtration and apparently has a nonglobular shape. Within this region, murine amino acids 315 to 350 and human amino acids 323 to 355 are sufficient for assembly of stable tetramers. The finding that murine amino acids 315 to 360 enhance transformation by other oncogenes strongly supports the role of p53 tetramerization in oncogenesis. Amino acids 330 to 390 of murine p53 and amino acids 340 to 393 of human p53, which have been implicated by Sturzbecher et al. in tetramerization (H.-W. Sturzbecher, R. Brain, C. Addison, K. Rudge, M. Remm, M. Grimaldi, E. Keenan, and J. R. Jenkins, Oncogene 7:1513-1523, 1992), do not form stable tetramers under our conditions. Our findings indicate that p53 has at least two autonomous oligomerization domains: a strong tetramerization domain in its C-terminal region and a weaker oligomerization domain in the central DNA binding region of p53. Together, these domains account for the formation of tetramers and multiples of tetramers by wild-type p53. The tetramerization domain is the major determinant of the dominant negative phenotype leading to transformation by mutant p53s.

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