Towers PR et al. (2005) J Neurochem "The Caenorhabditis elegans lev-8 gene encodes a novel type of nicotinic acetylcholine receptor alpha subunit."

Richmond JE, Towers PR, Sattelle DB, Edwards B

[J Neurochem, 2005]

Abstract We have cloned Caenorhabditis elegans lev-8 and demonstrated that it encodes a novel nicotinic acetylcholine receptor (nAChR) subunit (previously designated ACR-13), which has functional roles in body wall and uterine muscles as part of a levamisole-sensitive receptor. LEV-8 is an alpha subunit and is the first to be described from the ACR-8-like group, a new class of nAChR with atypical acetylcholine-binding site (loop C) and channel-lining motifs. A single base pair change in the first intron of lev-8 in lev-8(x15) mutants leads to alternative splicing and the introduction of a premature stop codon. lev-8(x15) worms are partially resistant to levamisole-induced egg laying and paralysis, phenotypes rescued by expression of the wild-type gene. lev-8(x15) worms also show reduced rates of pharyngeal pumping. Electrophysiological recordings from body wall muscle show that currents recorded in response to levamisole have reduced amplitude in lev-8(x15) compared with wild-type animals. Consistent with these phenotypic observations, green fluorescent protein fused to LEV-8 is expressed in body wall and uterine muscle, motor neurons and epithelial-derived socket cells. Thus, LEV-8 is a levamisole receptor subunit and exhibits the most diverse expression pattern of any invertebrate nAChR subunit studied to date.

McGhee JD (1987) Biochemistry "Purification and characterization of a carboxylesterase from the intestine of the nematode Caenorhabditis elegans."

McGhee JD

[Biochemistry, 1987]

The major intestinal esterase from the nematode Caenorhabditis elegans has been purified to essential homogeneity. Starting from whole worms, the overall purification is 9000-fold with a 10% recovery of activity. The esterase is a single polypeptide chain of Mr 60,000 and is stoichiometrically inhibited by organophosphates. Substrate preferences and inhibition patterns classify the enzyme as a carboxylesterase (EC 3.1.1.1), but the physiological function is unknown. The sequence of 13 amino acid residues at the esterase N- terminus has been determined. This partial sequence shows a surprisingly high degree of similarity to the N-terminal sequence of two carboxylesterases recently isolated from Drosophila mojavensis [Pen, J., van Beeumen, J., & Beintema, J. J. (1986) Biochem. J. 238, 691-699].

Nillegoda NB et al. (2015) Nature "Crucial HSP70 co-chaperone complex unlocks metazoan protein disaggregation."

Berynskyy M, Morimoto RI, Bukau B, Stengel F, Kirstein J, Szlachcic A, Arnsburg K, Stank A, Scior A, Nillegoda NB, Gao X, Guilbride DL, Aebersold R, Wade RC, Mayer MP

[Nature, 2015]

Protein aggregates are the hallmark of stressed and ageing cells, and characterize several pathophysiological states. Healthy metazoan cells effectively eliminate intracellular protein aggregates, indicating that efficient disaggregation and/or degradation mechanisms exist. However, metazoans lack the key heat-shock protein disaggregase HSP100 of non-metazoan HSP70-dependent protein disaggregation systems, and the human HSP70 system alone, even with the crucial HSP110 nucleotide exchange factor, has poor disaggregation activity in vitro. This unresolved conundrum is central to protein quality control biology. Here we show that synergic cooperation between complexed J-protein co-chaperones of classes A and B unleashes highly efficient protein disaggregation activity in human and nematode HSP70 systems. Metazoan mixed-class J-protein complexes are transient, involve complementary charged regions conserved in the J-domains and carboxy-terminal domains of each J-protein class, and are flexible with respect to subunit composition. Complex formation allows J-proteins to initiate transient higher order chaperone structures involving HSP70 and interacting nucleotide exchange factors. A network of cooperative class A and B J-protein interactions therefore provides the metazoan HSP70 machinery with powerful, flexible, and finely regulatable disaggregase activity and a further level of regulation crucial for cellular protein quality control.

Dreyfus DH et al. (1999) Mol Immunol "Comparative analysis of invertebrate Tc6 sequences that resemble the vertebrate V(D)J recombination signal sequences (RSS)."

Gelfand EW, Dreyfus DH

[Mol Immunol, 1999]

Invertebrate cells lack the p53 recombination checkpoint but contain mobile DNA sequences that transpose by a mechanism in part shared with excision of the V(D)J recombination signal sequences (RSS). In this work, inversion, deletion, and duplication of sequences associated with an invertebrate C. elegans Tc6 element is described. The structure of this C. elegans sequence and other dispersed Tc6 elements suggests that covalently closed 'hairpin' structures are not unique to excision of the V(D)J RSS by the RAG proteins, but rather can be generated by transposases at transposon termini leading to characteristic inversion and duplication events. Comparative analysis of recombination events at invertebrate sequences resembling the vertebrate V(D)J RSS may be useful in understanding V(D)J recombination-mediated recombination events in malignant vertebrate cells or genetic diseases such as ataxia telangectasia, in which the p53 recombination checkpoint is defective.

Samoylenko V et al. (2008) Phytother Res "Antiparasitic, nematicidal and antifouling constituents from Juniperus berries."

Ross SA, El-Feraly FS, Tekwani BL, Gafur MA, Bosselaers J, Mossa JS, Khan SI, Muhammad I, Samoylenko V, Dunbar DC

[Phytother Res, 2008]

A bioassay-guided fractionation of Juniperus procera berries yielded antiparasitic, nematicidal and antifouling constituents, including a wide range of known abietane, pimarane and labdane diterpenes. Among these, abieta-7,13-diene (1) demonstrated in vitro antimalarial activity against Plasmodium falciparum D6 and W2 strains (IC(50) = 1.9 and 2.0 microg/mL, respectively), while totarol (6), ferruginol (7) and 7beta-hydroxyabieta-8,13-diene-11,12-dione (8) inhibited Leishmania donovani promastigotes with IC(50) values of 3.5-4.6 microg/mL. In addition, totarol demonstrated nematicidal and antifouling activities against Caenorhabditis elegans and Artemia salina at a concentration of 80 microg/mL and 1 microg/mL, respectively. The resinous exudate of J. virginiana afforded known antibacterial E-communic acid (4) and 4-epi-abietic acid (5), while the volatile oil from its trunk wood revealed large quantities of cedrol (9). Using GC/MS, the two known abietanes totarol (6) and ferruginol (7) were identified from the berries of J. procera, J. excelsa and J. phoenicea.

Kirstein J et al. (2017) Aging Cell "In vivo properties of the disaggregase function of J-proteins and Hsc70 in Caenorhabditis elegans stress and aging."

Scior A, Nillegoda NB, Arnsburg K, Guilbride DL, Szlachcic A, Kirstein J, Bukau B, Morimoto RI

[Aging Cell, 2017]

Protein aggregation is enhanced upon exposure to various stress conditions and aging, which suggests that the quality control machinery regulating protein homeostasis could exhibit varied capacities in different stages of organismal lifespan. Recently, an efficient metazoan disaggregase activity was identified invitro, which requires the Hsp70 chaperone and Hsp110 nucleotide exchange factor, together with single or cooperating J-protein co-chaperones of classes A and B. Here, we describe how the orthologous Hsp70s and J-protein of Caenorhabditis elegans work together to resolve protein aggregates both invivo and invitro to benefit organismal health. Using an RNAi knockdown approach, we show that class A and B J-proteins cooperate to form an interactive flexible network that relocalizes to protein aggregates upon heat shock and preferentially recruits constitutive Hsc70 to disaggregate heat-induced protein aggregates and polyQ aggregates that form in an age-dependent manner. Cooperation between class A and B J-proteins is also required for organismal health and promotes thermotolerance, maintenance of fecundity, and extended viability after heat stress. This disaggregase function of J-proteins and Hsc70 therefore constitutes a powerful regulatory network that is key to Hsc70-based protein quality control mechanisms in metazoa with a central role in the clearance of aggregates, stress recovery, and organismal fitness in aging.

Pickering AM et al. (2013) J Exp Biol "A conserved role for the 20S proteasome and Nrf2 transcription factor in oxidative stress adaptation in mammals, Caenorhabditis elegans and Drosophila melanogaster."

Davies KJ, Pickering AM, Tower J, Sieburth DS, Staab TA

[J Exp Biol, 2013]

In mammalian cells, hydrogen peroxide (H(2)O(2))-induced adaptation to oxidative stress is strongly dependent on an Nrf2 transcription factor-mediated increase in the 20S proteasome. Here, we report that both Caenorhabditis elegans nematode worms and Drosophila melanogaster fruit flies are also capable of adapting to oxidative stress with H(2)O(2) pre-treatment. As in mammalian cells, this adaptive response in worms and flies involves an increase in proteolytic activity and increased expression of the 20S proteasome, but not of the 26S proteasome. We also found that the increase in 20S proteasome expression in both worms and flies, as in mammalian cells, is important for the adaptive response, and that it is mediated by the SKN-1 and CNC-C orthologs of the mammalian Nrf2 transcription factor, respectively. These studies demonstrate that stress mechanisms operative in cell culture also apply in disparate intact organisms across a wide biological diversity.

Wilson SM et al. (2002) Nat Genet "Synaptic defects in ataxia mice result from a mutation in Usp14, encoding a ubiquitin-specific protease."

Tessarollo L, Householder DB, Copeland NG, Rachel RA, Miller RJ, Jenkins NA, Fletcher CF, Bhattacharyya B, Coppola V, Wilson SM

[Nat Genet, 2002]

Mice that are homozygous with respect to a mutation (ax(J)) in the ataxia (ax) gene develop severe tremors by 2-3 weeks of age followed by hindlimb paralysis and death by 6-10 weeks of age. Here we show that ax encodes ubiquitin-specific protease 14 (Usp14). Ubiquitin proteases are a large family of cysteine proteases that specifically cleave ubiquitin conjugates. Although Usp14 can cleave a ubiquitin-tagged protein in vitro, it is unable to process polyubiquitin, which is believed to be associated with the protein aggregates seen in Parkinson disease, spinocerebellar ataxia type 1 (SCA1; ref. 4) and gracile axonal dystrophy (GAD). The physiological substrate of Usp14 may therefore contain a mono-ubiquitin side chain, the removal of which would regulate processes such as protein localization and protein activity. Expression of Usp14 is significantly altered in ax(J)/ax(J) mice as a result of the insertion of an intracisternal-A particle (IAP) into intron 5 of Usp14. In contrast to other neurodegenerative disorders such as Parkinson disease and SCA1 in humans and GAD in mice, neither ubiquitin-positive protein aggregates nor neuronal cell loss is detectable in the central nervous system (CNS) of ax(J) mice. Instead, ax(J) mice have defects in synaptic transmission in both the central and peripheral nervous systems. These results suggest that ubiquitin proteases are important in regulating synaptic activity in mammals.

Stern MJ et al. (1991) Development "A normally attractive cell interaction is repulsive in two C. elegans mesodermal cell migration mutants."

Stern MJ, Horvitz HR

[Development, 1991]

In wild-type Caenorhabditis elegans hermaphrodites, two bilaterally symmetric sex myoblasts (SMs) migrate anteriorly to flank the precise center of the gonad, where they divide to generate the muscles required for egg laying (J. E. Sulston and H. R. Horvitz (1977) Devl Biol. 56, 110-156). Although this migration is largely independent of the gonad, a signal from the gonad attracts the SMs to their precise final positions (J. H. Thomas, M. J. Stern and H. R. Horvitz (1990) Cell 62, 1041-1052). Here we show that mutations in either of two genes, egl-15 and egl-17, cause the premature termination of the migrations of the SMs. This incomplete migration is caused by the repulsion of the SMs by the same cells in the somatic gonad that are the source of the attractive signal in wild-type animals.

Reddy CS et al. (2010) Acta Chim Slov "Synthesis and in vitro Study of Some New Bis(thiadiazolyl-2H-pyrazolo[3,4-d][1,3]thiazole)-methanes as Potential Nematicides."

Yakub V, Rao DC, Reddy CS, Nagaraj A

[Acta Chim Slov, 2010]

A new series of bis(pyrazolo[3,4-d][1,3]thiazoles) 7a-j has been synthesized and characterized via IR, 1H NMR, 13C NMR, MS and elemental analyses. All the newly synthesized compounds 7a-j have been assayed for their nematicidal activity against Ditylenchus myceliophagus and Caenorhabditis elegans by aqueous in vitro screening technique. The screened data reveal that the compound 7e is most effective against D. myceliophagus and C. elegans with LD50 of 160 and 180 ppm respectively and is almost equal to the activity of the standard levamisole. The compounds 7h and 7j are also most active against C. elegans with LD50 of 190 ppm and D. myceliophagus with LD50 of 180 ppm, respectively. Further, 7a-j were screened for their antibacterial activity. Most of these new compounds showed potent activity against the test bacteria and emerged as potential molecules for further development.