Keller J et al. (2014) Biochem J "CYP-13A12 of the nematode Caenorhabditis elegans is a PUFA-epoxygenase involved in behavioural response to reoxygenation."

Ju J, Nehk E, Menzel R, Schunck WH, Falck JR, Keller J, Konkel A, Ma DK, Ellieva A

[Biochem J, 2014]

A specific behavioural response of Caenorhabditis elegans, the rapid increase of locomotion in response to anoxia/reoxygenation called the O2-ON response, has been used to model key aspects of ischaemia/reperfusion injury. A genetic suppressor screen demonstrated a direct causal role of CYP (cytochrome P450)-13A12 in this response and suggested that CYP-eicosanoids, which in mammals influence the contractility of cardiomyocytes and vascular smooth muscle cells, might function in C. elegans as specific regulators of the body muscle cell activity. In the present study we show that co-expression of CYP-13A12 with the NADPH-CYP-reductase EMB-8 in insect cells resulted in the reconstitution of an active microsomal mono-oxygenase system that metabolized EPA (eicosapentaenoic acid) and also AA (arachidonic acid) to specific sets of regioisomeric epoxy and hydroxy derivatives. The main products included 17,18-EEQ (17,18-epoxyeicosatetraenoic acid) from EPA and 14,15-EET (14,15-epoxyeicosatrienoic acid) from AA. Locomotion assays showed that the defective O2-ON response of C20-PUFA (polyunsaturated fatty acid)-deficient, -12 and -6 fatty acid desaturase mutants (fat-2 and fat-3 respectively) can be restored by feeding the nematodes AA or EPA, but not ETYA (eicosatetraynoic acid), a non-metabolizable AA analogue. Short-term incubation with 17,18-EEQ was sufficient to rescue the impaired locomotion of the fat-3 strain. The endogenous level of free 17,18-EEQ declined during anoxia and was rapidly restored in response to reoxygenation. On the basis of these results, we suggest that CYP-dependent eicosanoids such as 17,18-EEQ function as signalling molecules in the regulation of the O2-ON response in C. elegans. Remarkably, the exogenously administered 17,18-EEQ increased the locomotion activity under normoxic conditions and was effective not only with C20-PUFA-deficient mutants, but to a lesser extent also with wild-type worms.

Keller J et al. (2018) Toxins (Basel) "Toxicity Assay for Citrinin, Zearalenone and Zearalenone-14-Sulfate Using the Nematode Caenorhabditis elegans as Model Organism."

RueB L, Haase H, Koch M, Keller J, Borzekowski A, Menzel R

[Toxins (Basel), 2018]

To keep pace with the rising number of detected mycotoxins, there is a growing need for fast and reliable toxicity tests to assess potential threats to food safety. Toxicity tests with the bacterial-feeding nematode <i>Caenorhabditis elegans</i> as the model organism are well established. In this study the <i>C. elegans</i> wildtype strain N2 (var. Bristol) was used to investigate the toxic effects of the food-relevant mycotoxins citrinin (CIT) and zearalenone-14-sulfate (ZEA-14-S) and zearalenone (ZEA) on different life cycle parameters including reproduction, thermal and oxidative stress resistance and lifespan. The metabolization of the mycotoxins by the nematodes in vivo was investigated using HPLC-MS/MS. ZEA was metabolized in vivo to the reduced isomers &amp;alpha;-zearalenol (&amp;alpha;-ZEL) and &amp;beta;-ZEL. ZEA-14-S was reduced to &amp;alpha;-/&amp;beta;-ZEL-14-sulfate and CIT was metabolized to mono-hydroxylated CIT. All mycotoxins tested led to a significant decrease in the number of nematode offspring produced. ZEA and CIT displayed negative effects on stress tolerance levels and for CIT an additional shortening of the mean lifespan was observed. In the case of ZEA-14-S, however, the mean lifespan was prolonged. The presented study shows the applicability of <i>C. elegans</i> for toxicity testing of emerging food mycotoxins for the purpose of assigning potential health threats.

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].

Spector MS et al. (1995) International C. elegans Meeting "LOCALIZATION OF CED-9; A GENE PRODUCT REQUIRED FOR CELL SURVIVAL"

Hengartner MO, Keller J, Spector MS

[International C. elegans Meeting, 1995]

In C. elegans, the process of programmed cell death occurs reproducibly during development in specific cell lineages from one generation to the next. In addition, cell corpses begin to appear in the syncytial region of the hermaphrodite gonad after the L4/adult molt (see abstract by Gumienny et al.). A number of genes that function in programmed cell death have been identified. Two genes, ced-3 and ced-4, are required to "run" the cell death program. Loss-of-function mutations in either of these genes prevent all programmed cell deaths in C. elegans. A third gene, ced-9, is required to protect cells that normally live from undergoing programmed cell death: in ced-9(lf) mutants, many cells that normally live undergo programmed cell death. Genetic studies suggest that ced-9 acts by antagonizing the action of ced-3 and/or ced-4. Determination of the subcellular and developmental expression patterns will provide insight into ced-9 function. Toward this end, we are developing polyclonal and monoclonal antibodies against the CED-9 protein and will be examining the localization of CED-9 throughout development and in adult animals in various mutant backgrounds by immunocytochemistry. These antibodies will also be used in immunoprecipitation experiments for identifying proteins that associate with CED-9.

Murakami S et al. (1999) Curr Biol "Life extension and stress resistance in Caenorhabditis elegans modulated by the tkr-1 gene."

Johnson TE, Murakami S

[Curr Biol, 1999]

In this Brief Communication, which appeared in the 14 September 1998 issue of Current Biology, the UV dose was reported erroneously. The dose reported was 20 J/m2 but the actual dose used was 0.4 J/cm2. Also, the gene formally referred to as tkr-1 has since been renamed old-1 (overexpression longevity determination).

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

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

[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.

Ramos CG et al. (2014) J Bacteriol "Retraction for Ramos et al., MtvR is a global small noncoding regulatory RNA in Burkholderia cenocepacia."

Leitao JH, da Costa PJ, Grilo AM, Feliciano JR, Ramos CG

[J Bacteriol, 2014]

Volume 195, no. 16, p. 35143523, 2013. A number of problems related to images published in this paper have been brought to our attention. Figure 1D contains duplicated images in lanes S and LE, and Fig. 4D and 6B contain images previously published in articles in this journal and in Microbiology and Microbial Pathogenesis, i.e., the following: C. G. Ramos, S. A. Sousa, A. M. Grilo, J. R. Feliciano, and J. H. Leitao, J. Bacteriol. 193:15151526, 2011. doi:10.1128/JB.01374-11. S. A. Sousa, C. G. Ramos, L. M. Moreira, and J. H. Leitao, Microbiology 156:896908, 2010. doi:10.1099/mic.0.035139-0. C. G. Ramos, S. A. Sousa, A. M. Grilo, L. Eberl, and J. H. Leitao, Microb. Pathog. 48:168177, 2010. doi: 10.1016/j.micpath.2010.02.006. Therefore, we retract the paper. We deeply regret this situation and apologize for any inconvenience to the editors and readers of Journal of Bacteriology, Microbial Pathogenesis, and Microbiology.

Miller DM et al. (1992) Worm Breeder's Gazette "unc-4 LacZ Expression in A-Type Motor Neurons"

Miller DM, Niemeyer CJ

[Worm Breeder's Gazette, 1992]

unc-4 LacZ expression in A-type motor neurons David M. Miller and Charles J. Niemeyer, Dept. of Cell Biology, Duke Univ. Medical Ctr, Durham, NC 27710

Sommer RJ et al. (1994) Worm Breeder's Gazette "Evolution of Vulva-Formation: Part II: Species With a Central Vulva"

Sternberg PW, Sommer RJ

[Worm Breeder's Gazette, 1994]

Evolution of vulva-formation: Part II: Species with a central vulva Ralf J. Sommer & Paul W. Sternberg, California Institute of Technology, Division of Biology 156-29, Pasadena, CA 91125

Jefferis GSXE et al. (1995) International C. elegans Meeting "A TWO-HYBRID SCREEN FOR CED-9 INTERACTING PROTEINS"

Hoeppner DJ, Hengartner MO, Keller J, Jefferis GSXE

[International C. elegans Meeting, 1995]

Genetic analysis of the developmental cell death pathway in C. elegans has led to the identification of ced (cell death abnormal) genes, the definition of an epistatic pathway, and its classification into decision (cell specific), execution, engulfment and degradation phases. In order to complement this genetic work, we are undertaking a yeast two hybrid screen. ced-9 has been identified as a cell death suppressor, in which (lf) and (gf) mutations lead to ectopic programmed cell death and survival respectively. It in turn negatively regulates ced-3 and ced-4, which appear to be required for all cell suicides. bcl-2, a mammalian protooncogene, was the first identified member of a family of weakly homologous genes with cell death/survival activities, which includes ced-9. Members of this family seem to interact extensively by homo- and heterodimerisation via conserved regions which CED-9 retains; it is postulated that these interactions may be responsible for regulating downstream genes (e.g., ced-3/ced-4 in C. elegans) and thereby controlling cell death. After initial difficulties with full length bait protein toxicity, we have made a fusion protein construct with the GAL4-DNA binding domain (DB) and amino acids 1-247 of CED-9 thereby excluding the carboxy-terminal putative membrane-spanning region. The fusion is stably expressed (shown by western blot) and does not transactivate by itself. We have received a GAL4 activation domain tagged C. elegans cDNA library (courtesy of David Vaux) and are therefore in a position to start screening. What might the products of such a screen be? The pathway produced by genetic analysis probably contains "holes" to be filled. If we should find one of the upstream or downstream genes which have already been cloned, that would be evidence of a physical and not just genetic interaction. Any interactions demonstrated in the two hybrid system must be interpreted with caution. We therefore intend to use CED-9 antibodies - currently being generated - to confirm interactions by co-immunoprecipitation.