scholarly journals A Family of K+ Channel Ancillary Subunits Regulate Taste Sensitivity in Caenorhabditis elegans

2005 ◽  
Vol 280 (23) ◽  
pp. 21893-21899 ◽  
Author(s):  
Ki Ho Park ◽  
Leonardo Hernandez ◽  
Shi-Qing Cai ◽  
Yi Wang ◽  
Federico Sesti

We have identified a family of ancillary subunits of K+ channels in Caenorhabditis elegans. MPS-1 and its related members MPS-2, MPS-3, and MPS-4 are detected in the nervous system of the nematode. Electrophysiological analysis in ASE neurons and mammalian cells and epigenetic inactivation by double-stranded RNA interference (RNAi) in vivo show that each MPS can associate with and functionally endow the voltage-gated K+ channel KVS-1. In the chemosensory neuron ADF, three different MPS subunits combine with KVS-1 to form both binary (MPS-1·KVS-1) and ternary (MPS-2·MPS-3·KVS-1) complexes. RNAi of mps-2, mps-3, or both, enhance the taste of the animal for sodium without altering the susceptibility to other attractants. When sodium is introduced in the test plate as background or as antagonist attractant, the nematode loses the ability to recognize a second attractant. Thus, it appears that the chemosensory apparatus of C. elegans uses sensory thresholds and that a voltage-gated K+ channel is specifically required for this mechanism.

2007 ◽  
Vol 35 (1) ◽  
pp. 129-132 ◽  
Author(s):  
H.A. Baylis ◽  
K. Goyal

The nematode Caenorhabditis elegans contains over 20 genes for TRP (transient receptor potential) channels which include members of all of the subclasses identified in mammalian cells. These proteins include three members of the TRPM (TRP melastatin) family: gon-2 (abnormal gonad development), gtl-1 (gon-2-like 1) and gtl-2. Although studies of these genes are at an early stage, we are beginning to understand their functions in the life of C. elegans. Mutations in gon-2 have defective gonad formation because of failures in the cell division of the somatic gonad precursor cells. gon-2 and gtl-1 are both expressed in the intestine of the animal. Experiments on gon-2,gtl-1 double mutants show that they have a severe growth defect that is ameliorated by the addition of high levels of Mg2+ to the growth medium. gon-2,gtl-1 double mutants have defective magnesium homoeostasis and also have altered sensitivity to toxic levels of Ni2+. Furthermore gon-2 mutants have reduced levels of IORCa (outwardly rectifying calcium current) in the intestinal cells. Thus these two channels appear to play an important role in cation homoeostasis in C. elegans. In addition, perturbing the function of gon-2 and gtl-1 disrupts the ultradian defecation rhythm in C. elegans, suggesting that these channels play an important role in regulating this calcium-dependent rhythmic process. The tractability of C. elegans as an experimental animal and its amenability to techniques such as RNAi (RNA interference) and in vivo imaging make it an excellent system for an integrative analysis of TRPM function.


2021 ◽  
pp. 1-9
Author(s):  
Dayana Torres Valladares ◽  
Sirisha Kudumala ◽  
Murad Hossain ◽  
Lucia Carvelli

Amphetamine is a potent psychostimulant also used to treat attention deficit/hyperactivity disorder and narcolepsy. In vivo and in vitro data have demonstrated that amphetamine increases the amount of extra synaptic dopamine by both inhibiting reuptake and promoting efflux of dopamine through the dopamine transporter. Previous studies have shown that chronic use of amphetamine causes tolerance to the drug. Thus, since the molecular mechanisms underlying tolerance to amphetamine are still unknown, an animal model to identify the neurochemical mechanisms associated with drug tolerance is greatly needed. Here we took advantage of a unique behavior caused by amphetamine in <i>Caenorhabditis elegans</i> to investigate whether this simple, but powerful, genetic model develops tolerance following repeated exposure to amphetamine. We found that at least 3 treatments with 0.5 mM amphetamine were necessary to see a reduction in the amphetamine-induced behavior and, thus, to promote tolerance. Moreover, we found that, after intervals of 60/90 minutes between treatments, animals were more likely to exhibit tolerance than animals that underwent 10-minute intervals between treatments. Taken together, our results show that <i>C. elegans</i> is a suitable system to study tolerance to drugs of abuse such as amphetamines.


Development ◽  
1992 ◽  
Vol 114 (2) ◽  
pp. 317-330 ◽  
Author(s):  
O. Bossinger ◽  
E. Schierenberg

The pattern of autofluorescence in the two free-living namatodes Rhabditis dolichura and Caenorhabditis compared. In C. elegans, during later embryogenesis cells develop a typical bluish autofluorescence as illumination, while in Rh. dolichura a strong already present in the unfertilized egg. Using a new,


2016 ◽  
Vol 147 (2) ◽  
pp. 105-125 ◽  
Author(s):  
Elke Bocksteins

Members of the electrically silent voltage-gated K+ (Kv) subfamilies (Kv5, Kv6, Kv8, and Kv9, collectively identified as electrically silent voltage-gated K+ channel [KvS] subunits) do not form functional homotetrameric channels but assemble with Kv2 subunits into heterotetrameric Kv2/KvS channels with unique biophysical properties. Unlike the ubiquitously expressed Kv2 subunits, KvS subunits show a more restricted expression. This raises the possibility that Kv2/KvS heterotetramers have tissue-specific functions, making them potential targets for the development of novel therapeutic strategies. Here, I provide an overview of the expression of KvS subunits in different tissues and discuss their proposed role in various physiological and pathophysiological processes. This overview demonstrates the importance of KvS subunits and Kv2/KvS heterotetramers in vivo and the importance of considering KvS subunits and Kv2/KvS heterotetramers in the development of novel treatments.


Nutrients ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 2002 ◽  
Author(s):  
Cristina Moliner ◽  
Lillian Barros ◽  
Maria Dias ◽  
Víctor López ◽  
Elisa Langa ◽  
...  

Tagetes erecta L. has long been consumed for culinary and medicinal purposes in different countries. The aim of this study was to explore the potential benefits from two cultivars of T. erecta related to its polyphenolic profile as well as antioxidant and anti-aging properties. The phenolic composition was analyzed by LC-DAD-ESI/MSn. Folin-Ciocalteu, DPPH·, and FRAP assays were performed in order to evaluate reducing antiradical properties. The neuroprotective potential was evaluated using the enzymes acetylcholinesterase and monoamine oxidase. Caenorhabditis elegans was used as an in vivo model to assess extract toxicity, antioxidant activity, delayed aging, and reduced β-amyloid toxicity. Both extracts showed similar phenolic profiles and bioactivities. The main polyphenols found were laricitin and its glycosides. No acute toxicity was detected for extracts in the C. elegans model. T. erecta flower extracts showed promising antioxidant and neuroprotective properties in the different tested models. Hence, these results may add some information supporting the possibilities of using these plants as functional foods and/or as nutraceutical ingredients.


2005 ◽  
Vol 73 (11) ◽  
pp. 7236-7242 ◽  
Author(s):  
Creg Darby ◽  
Sandya L. Ananth ◽  
Li Tan ◽  
B. Joseph Hinnebusch

ABSTRACT Yersinia pestis, the cause of bubonic plague, blocks feeding by its vector, the flea. Recent evidence indicates that blockage is mediated by an in vivo biofilm. Y. pestis and the closely related Yersinia pseudotuberculosis also make biofilms on the cuticle of the nematode Caenorhabditis elegans, which block this laboratory animal's feeding. Random screening of Y. pseudotuberculosis transposon insertion mutants with a C. elegans biofilm assay identified gmhA as a gene required for normal biofilms. gmhA encodes phosphoheptose isomerase, an enzyme required for synthesis of heptose, a conserved component of lipopolysaccharide and lipooligosaccharide. A Y. pestis gmhA mutant was constructed and was severely defective for C. elegans biofilm formation and for flea blockage but only moderately defective in an in vitro biofilm assay. These results validate use of the C. elegans biofilm system to identify genes and pathways involved in Y. pestis flea blockage.


2007 ◽  
Vol 35 (5) ◽  
pp. 1064-1068 ◽  
Author(s):  
D.P. Mohapatra ◽  
K.-S. Park ◽  
J.S. Trimmer

Voltage-gated K+ channels are key regulators of neuronal excitability. The Kv2.1 voltage-gated K+ channel is the major delayed rectifier K+ channel expressed in most central neurons, where it exists as a highly phosphorylated protein. Kv2.1 plays a critical role in homoeostatic regulation of intrinsic neuronal excitability through its activity- and calcineurin-dependent dephosphorylation. Here, we review studies leading to the identification and functional characterization of in vivo Kv2.1 phosphorylation sites, a subset of which contribute to graded modulation of voltage-dependent gating. These findings show that distinct developmental-, cell- and state-specific regulation of phosphorylation at specific sites confers a diversity of functions on Kv2.1 that is critical to its role as a regulator of intrinsic neuronal excitability.


Antioxidants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 811
Author(s):  
Cristina Moliner ◽  
Víctor López ◽  
Lillian Barros ◽  
Maria Inês Dias ◽  
Isabel C. F. R. Ferreira ◽  
...  

Rosmarinus officinalis L., commonly known as rosemary, has been largely studied for its wide use as food ingredient and medicinal plant; less attention has been given to its edible flowers, being necessary to evaluate their potential as functional foods or nutraceuticals. To achieve that, the phenolic profile of the ethanolic extract of R. officinalis flowers was determined using LC-DAD-ESI/MSn and then its antioxidant and anti-ageing potential was studied through in vitro and in vivo assays using Caenorhabditis elegans. The phenolic content was 14.3 ± 0.1 mg/g extract, trans rosmarinic acid being the predominant compound in the extract, which also exhibited a strong antioxidant capacity in vitro and increased the survival rate of C. elegans exposed to lethal oxidative stress. Moreover, R. officinalis flowers extended C. elegans lifespan up to 18%. Therefore, these findings support the potential use of R. officinalis flowers as ingredients to develop products with pharmaceutical and/or nutraceutical potential.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Marcello Germoglio ◽  
Anna Valenti ◽  
Ines Gallo ◽  
Chiara Forenza ◽  
Pamela Santonicola ◽  
...  

AbstractFanconi Anemia is a rare genetic disease associated with DNA repair defects, congenital abnormalities and infertility. Most of FA pathway is evolutionary conserved, allowing dissection and mechanistic studies in simpler model systems such as Caenorhabditis elegans. In the present study, we employed C. elegans to better understand the role of FA group D2 (FANCD2) protein in vivo, a key player in promoting genome stability. We report that localization of FCD-2/FANCD2 is dynamic during meiotic prophase I and requires its heterodimeric partner FNCI-1/FANCI. Strikingly, we found that FCD-2 recruitment depends on SPO-11-induced double-strand breaks (DSBs) but not RAD-51-mediated strand invasion. Furthermore, exposure to DNA damage-inducing agents boosts FCD-2 recruitment on the chromatin. Finally, analysis of genetic interaction between FCD-2 and BRC-1 (the C. elegans orthologue of mammalian BRCA1) supports a role for these proteins in different DSB repair pathways. Collectively, we showed a direct involvement of FCD-2 at DSBs and speculate on its function in driving meiotic DNA repair.


2018 ◽  
Vol 293 (43) ◽  
pp. 16912-16922 ◽  
Author(s):  
Shanqing Zheng ◽  
Hilton Chiu ◽  
Jeffrey Boudreau ◽  
Tony Papanicolaou ◽  
William Bendena ◽  
...  

The human genome encodes 10 insulin-like genes, whereas the Caenorhabditis elegans genome remarkably encodes 40 insulin-like genes. Knockout strategies to determine the roles of all the insulin/insulin-like peptide ligands (INS) in C. elegans has been challenging due to functional redundancy. Here, we individually overexpressed each of the 40 ins genes pan-neuronally, and monitored multiple phenotypes including: L1 arrest life span, neuroblast divisions under L1 arrest, dauer formation, and fat accumulation, as readouts to characterize the functions of each INS in vivo. Of the 40 INS peptides, we found functions for 35 INS peptides and functionally categorized each as agonists, antagonists, or of pleiotropic function. In particular, we found that 9 of 16 agonistic INS peptides shortened L1 arrest life span and promoted neuroblast divisions during L1 arrest. Our study revealed that a subset of β-class INS peptides that contain a distinct F peptide sequence are agonists. Our work is the first to categorize the structures of INS peptides and relate these structures to the functions of all 40 INS peptides in vivo. Our findings will promote the study of insulin function on development, metabolism, and aging-related diseases.


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