Luo H et al. (2024) J Lipid Res "Sphingolipid profiling reveals differential functions of sphingolipid biosynthesis isozymes of C. elegans."

Wu G, Xia Y, Dong MQ, Luo H, Zhao X, Wang ZD, Ma Y

[J Lipid Res, 2024]

Multiple isozymes are encoded in the C. elegans genome for the various sphingolipid biosynthesis reactions, but the contributions of individual isozymes are characterized only in part. We developed a simple but effective reversed-phase liquid chromatography-tandem mass spectrometry (RPLC-MS/MS) method that enables simultaneous identification and quantification of ceramides (Cer), glucosylceramides (GlcCer), and sphingomyelins (SM), three important classes of sphingolipids from the same MS run. Validating this sphingolipid profiling method, we show that nearly all 47 quantifiable sphingolipid species found in young adult worms were reduced upon RNA interference (RNAi) of sptl-1 or elo-5, which are required for synthesis of the id17:1 sphingoid base. We also confirm that HYL-1 and HYL-2, but not LAGR-1, constitute the major ceramide synthase activity with different preference for fatty acid substrates, and that CGT-3, but not CGT-1 and CGT-2, plays a major role in producing glucosylceramides. Deletion of sms-5 hardly affects SM levels. RNAi of sms-1, -2, and -3 all lower the abundance of sphingomyelins with an odd number of carbon atoms (mostly C21 and C23, with or without hydroxylation) in the N-acyl chain, and only sms-1 RNAi does not elevate sphingomyelins containing even-numbered N-acyl chains. This suggests that sphingolipids containing even-numbered N-acyl chains could be regulated separately, sometimes in opposite directions, with those containing odd-numbered N-acyls, presumably monomethyl branched chain fatty acyls. We also find that ceramide levels are kept in balance with those of glucosylceramides and sphingomyelins.

Luo H et al. (2013) Appl Microbiol Biotechnol "The effects of Bacillus thuringiensis Cry6A on the survival, growth, reproduction, locomotion, and behavioral response of Caenorhabditis elegans."

Xiong J, Yu Z, Luo H, Xia L, Zhou Q

[Appl Microbiol Biotechnol, 2013]

Several families of crystal proteins from Bacillus thuringiensis exhibit nematicidal activity. Cry5B protein, a pore-forming toxin, has been intensively studied yielding many insights into the mode of action of crystal protein at molecular level and pathogenesis of pore-forming toxins. However, little attention was paid to Cry6A, another representative nematicidal crystal protein. Cry6A shares very low homology with Cry5B at amino acid sequence and probably acts in a distinct pathway from Cry5B and even the other main commercial crystal proteins. In the current study, we comprehensively investigated the nematicidal properties of Cry6Aa2 against the free-living soil nematode Caenorhabditis elegans and examined the physical response of C. elegans to Cry6Aa2 attack. Our results indicate that Cry6Aa2 exhibits high lethal activity to C. elegans and could cause detrimental effects on C. elegans, including obviously suppressed growth, decreased brood size, and even abnormal motility. Meanwhile, our study additionally shows that C. elegans could defend against the Cry6Aa2 toxin harmful threat through behavioral defense responses, such as reduced oral uptake and physical avoidance. In general, this study suggests that Cry6Aa2 possesses diverse nematicidal properties, which strongly indicates that Cry6Aa2 is a promising potential candidate of nematicidal agent. Moreover, this study highlights the importance of behavioral responses in defense of C. elegans for survival and demonstrates the key role of crystal protein in the interaction of B. thuringiensis-C. elegans. These findings could shed light on understanding the interaction of C. elegans with B. thuringiensis and provide a perfect model to study the role of pathogenic factor in the interaction of pathogen-host.

Thomas JH et al. (1994) Worm Breeder's Gazette "lin-36, a Class B Synthetic Multivulva Gene, Encodes a Novel Protein"

Thomas JH, Horvitz HR

[Worm Breeder's Gazette, 1994]

lin-36, a Class B Synthetic Multivulva Gene, Encodes a Novel Protein Jeffrey H. Thomas and H. Robert Horvitz, HHMI, Dept. Biology, MIT, Cambridge, MA 02139, USA

Sun J et al. (2013) Exp Parasitol "Parasitism of secondary-stage juvenile of Heterodera glycines and four larva stages of Caenorhabditis elegans by Hirsutella spp."

Sun J, Xie H, Xiang M, Liu X, Qiu J

[Exp Parasitol, 2013]

The fungi Hirsutella rhossiliensis and Hirsutella minnesotensis generally parasitize only plant-parasitic nematodes in nature but parasitize the bacterivorous nematode Caenorhabditis elegans on agar plates. To establish a model system for studying the interaction between fungi and nematodes, we compared the parasitism of the first- to fourth-stage larvae (L1-L4) of C. elegans and second-stage juvenile (J2) of Heterodera glycines by twenty isolates of Hirsutella spp. Although parasitism differed substantially among isolates, both H. minnesotensis and H. rhossiliensis parasitized a higher percentage of H. glycines J2s than of C. elegans larvae. Parasitism of C. elegans L1s was correlated with parasitism of H. glycines J2s. Parasitism of C. elegans by H. rhossiliensis and H. minnesotensis was negatively correlated with larva size and motility, i.e., parasitism was higher for the younger stages. The C. elegans L1 is recommended for studying parasitism of nematodes by H. rhossiliensis and H. minnesotensis.

Fei YJ et al. (2000) J Biol Chem "A novel H(+)-coupled oligopeptide transporter (OPT3) from Caenorhabditis elegans with a predominant function as a H(+) channel and an exclusive expression in neurons."

Leibach FH, Romero MF, Krause MW, Huang W, Ganapathy V, Fei YJ, Liu JC

[J Biol Chem, 2000]

We have cloned and functionally characterized a novel, neuron-specific, H(+)-coupled oligopeptide transporter (OPT3) from Caenorhabditis elegans that functions predominantly as a H(+) channel. The opt3 gene is approximately 4.4 kilobases long and consists of 13 exons. The cDNA codes for a protein of 701 amino acids with 11 putative transmembrane domains. When expressed in mammalian cells and in Xenopus laevis oocytes, OPT3 cDNA induces H(+)-coupled transport of the dipeptide glycylsarcosine. Electrophysiological studies of the transport function of OPT3 in Xenopus oocytes show that this transporter, although capable of mediating H(+)-coupled peptide transport, functions predominantly as a H(+) channel. The H(+) channel activity of OPT3 is approximately 3-4-fold greater than the H(+)/peptide cotransport activity as determined by measurements of H(+) gradient-induced inward currents in the absence and presence of the dipeptide using the two-microelectrode voltage clamp technique. A downhill influx of H(+) was accompanied by a large intracellular acidification as evidenced from the changes in intracellular pH using an ion-selective microelectrode. The H(+) channel activity exhibits a K(0.5)(H) of 1.0 microM at a membrane potential of -50 mV. At the level of primary structure, OPT3 has moderate homology with OPT1 and OPT2, two other H(+)-coupled oligopeptide transporters previously cloned from C. elegans. Expression studies using the opt3::gfp fusion constructs in transgenic C. elegans demonstrate that opt3 gene is exclusively expressed in neurons. OPT3 may play an important physiological role as a pH balancer in the maintenance of H(+) homeostasis in C. elegans.

Imadzu H et al. (1994) Worm Breeder's Gazette "Two Tropomyosins Expressed in Body Wall and the Third Did In Pharynx of Caenorhabditis elegans"

Kagawa H, Sakube Y, Imadzu H

[Worm Breeder's Gazette, 1994]

TWO TROPOMYOSINS EXPRBSSBD IN BODY WALL AND THE THIRD DID IN PHARYNX OF CAENORHABDDITIS ELEGANS. H. Imadzu, Y. Sakube and H. gagawa. Department of Biology, Faculty of Science, Okayama University, Okayama, 700 Japan.

Wilson PA et al. (1982) Parasitology "Strongyloides ratti (homogonic): the time-course of early migration in the generalized host deduced from experiments in lactating rats."

Steven GE, Simpson NE, Wilson PA

[Parasitology, 1982]

Unsuckled mother rats given a 1 h suckling stimulus 3 h after subcutaneous injection of an exact dose of homogonic Strongyloides ratti allow fewer worms to develop in their intestines by day 9 than nulliparous rats (Wilson & Simpson, 1981). This effect is studied in more detail in terms of the length of time between weaning and stimulus (W leads to S) and injection and stimulus (I leads to S). It was observable with a W leads to S of 30 h but this and a period of 5 h were less effective than 24 h. With W leads to S constant at 24 h, significantly more worms developed in mothers when I leads to S was 24 h compared to 3 h and 10 h (P less than 0.005). The data, combined with those from nulliparous controls, are presented as a measure of the change with time of numbers of larvae in that compartment of the system which gives access to the stimulated mammary gland. It is argued that the particular compartment is the local lymph node draining the injection site and that the kinetics deduced are applicable to migration in the rat in general.

Miller DL et al. (2007) Proc Natl Acad Sci U S A "Hydrogen sulfide increases thermotolerance and lifespan in Caenorhabditis elegans."

Miller DL, Roth MB

[Proc Natl Acad Sci U S A, 2007]

Hydrogen sulfide (H(2)S) is naturally produced in animal cells. Exogenous H(2)S has been shown to effect physiological changes that improve the capacity of mammals to survive in otherwise lethal conditions. However, the mechanisms required for such alterations are unknown. We investigated the physiological response of Caenorhabditis elegans to H(2)S to elucidate the molecular mechanisms of H(2)S action. Here we show that nematodes exposed to H(2)S are apparently healthy and do not exhibit phenotypes consistent with metabolic inhibition. Instead, animals exposed to H(2)S are thermotolerant and long-lived. These phenotypes require SIR-2.1 activity but are genetically independent of the insulin signaling pathway, mitochondrial dysfunction, and caloric restriction. These studies suggest that SIR-2.1 activity may translate environmental change into physiological alterations that improve survival. It is interesting to consider the possibility that the mechanisms by which H(2)S increases thermotolerance and lifespan in nematodes are conserved and that studies using C. elegans may help explain the beneficial effects observed in mammals exposed to H(2)S.

Sakube Y et al. (1994) Worm Breeder's Gazette "The Genome Structure and Expression of Promoter/lacZ Fusion Genes of C. elegans Ryanodine Receptor"

Imadzu H, Sakube Y, Kagawa H

[Worm Breeder's Gazette, 1994]

The Genome Structure and Expression of Promoter/lacZ Fusion Genes of the C. elegans Ryanodine Receptor Y. Sakube, H. Imadzu and H. Kagawa, Laboratory of Molecular Biology, Faculty of Science, Okayama University, Okayama, 700 Japan C51918@JPNKUDPC

Valles P et al. (2006) Semin Nephrol "Kidney vacuolar H+ -ATPase: physiology and regulation."

Wysocki J, Batlle D, Lapointe MS, Valles P

[Semin Nephrol, 2006]

The vacuolar H(+)-ATPase is a multisubunit protein consisting of a peripheral catalytic domain (V(1)) that binds and hydrolyzes adenosine triphosphate (ATP) and provides energy to pump H(+) through the transmembrane domain (V(0)) against a large gradient. This proton-translocating vacuolar H(+)-ATPase is present in both intracellular compartments and the plasma membrane of eukaryotic cells. Mutations in genes encoding kidney intercalated cell-specific V(0) a4 and V(1) B1 subunits of the vacuolar H(+)-ATPase cause the syndrome of distal tubular renal acidosis. This review focuses on the function, regulation, and the role of vacuolar H(+)-ATPases in renal physiology. The localization of vacuolar H(+)-ATPases in the kidney, and their role in intracellular pH (pHi) regulation, transepithelial proton transport, and acid-base homeostasis are discussed.