Hecht RM et al. (1983) Worm Breeder's Gazette "embryonic-arrest mutant of C elegans fails to phosphorylate mitosis-specific phosphoproteins."

Davis FM, Hecht RM, Berg-Zabelshansky M

[Worm Breeder's Gazette, 1983]

A family of mitosis-specific phosphoproteins has been recognized by a monoclonal antibody prepared against HeLa mitotic cell extracts ( Davis et al., PNAS 80:2969, 1983). The importance of these phosphoproteins for mitosis (M) is emphasized by their conserved presence in the wild-type nematode, Caenorhabditis r absence at restrictive temperature in one of the temperature-sensitive embryonic arrest mutants, emb-29(g52) and its allele b262. The mitotic index of wild-type and mutant embryos was determined immunocytochemically. At the 250 to 300-cell stage, wild-type embryos exhibited about 16% immunoreactive cells. In contrast, less than 1% of the cells in mutant embryos arrested at restrictive temperature were immunoreactive. However, when arrested embryos were placed on ice for 3-5 hr, up to 90% of their cells were able to enter mitosis and become immunoreactive. Wild-type embryos reached their maximal mitotic index of about 16% during the 4 C incubation. Hence, emb-29 seems to define a cell division cycle function that arrests embryonic cells close to the G2/M interface. The highly conserved antigenic epitope is associated with a family of high molecular weight polypeptides with major bands at 127, 97 and 77 kd. Nearly all of these proteins copurify with a nuclear-cytoskeleton complex. The nematode, unlike other species, elicits a strong reaction at the asters. As in mammalian cells, antigenic reactivity of these multiple proteins depends on their phosphorylation, since antibody binding is reduced after aIkaline phosphatase treatment. These experiments suggest that the emb-29 mutation affects an essential phosphorylation activity required for progression into M. In addition, several embryonic lethal mutants previously shown to form anucleate cells when cultured at restrictive temperature (Hecht et al., (1982) Develop. Biol. 94, 183-191.) could be stained with the mitosis-specific antibody over regions that did not stain for nuclear DNA. This demonstrates that the mitosis-specific protein complex may be prelocalized independently of nuclear DNA and provides additional support for the earlier notion that cytokinesis may also occur independently of nuclear division.

Hecht RM et al. (1987) J Cell Sci "Conditional absence of mitosis-specific antigens in a temperature-sensitive embryonic-arrest mutant of Caenorhabditis elegans."

Davis FM, Berg-Zabelshansky M, Hecht RM, Rao PN

[J Cell Sci, 1987]

A monoclonal antibody, specific to phosphoproteins in mitotic HeLa cells was found to crossreact with a similar set of proteins in embryos of the nematode, Caenorhabditis elegans. In C. elegans, as in mammalian cells, the highly conserved antigenic epitope is associated with a family of high molecular weight polypeptides. The antigenic reactivity of these multiple proteins also depends on their phosphorylation, since antibody binding is reduced after alkaline phosphatase treatment. The antigens are detected at the centrosomes, and in the nuclear region and surrounding cytoplasm of mitotic cells. The significance of these antigens is emphasized by their absence at restrictive temperature in embryos of the temperature-sensitive embryonic-arrest mutant, emb-29V. Furthermore, temperature shift-down experiments suggest that the emb-29 mutation defines a cell division cycle function that affects an essential activity required for progression into M phase.

Wypijewska A et al. (2012) Biochemistry "7-methylguanosine diphosphate (m(7)GDP) is not hydrolyzed but strongly bound by decapping scavenger (DcpS) enzymes and potently inhibits their activity."

Wypijewska A, Darzynkiewicz E, Davis RE, Jemielity J, Bojarska E, Lukaszewicz M, Stepinski J

[Biochemistry, 2012]

Decapping scavenger (DcpS) enzymes catalyze the cleavage of a residual cap structure following 3' 5' mRNA decay. Some previous studies suggested that both m(7)GpppG and m(7)GDP were substrates for DcpS hydrolysis. Herein, we show that mononucleoside diphosphates, m(7)GDP (7-methylguanosine diphosphate) and m(3)(2,2,7)GDP (2,2,7-trimethylguanosine diphosphate), resulting from mRNA decapping by the Dcp1/2 complex in the 5' 3' mRNA decay, are not degraded by recombinant DcpS proteins (human, nematode, and yeast). Furthermore, whereas mononucleoside diphosphates (m(7)GDP and m(3)(2,2,7)GDP) are not hydrolyzed by DcpS, mononucleoside triphosphates (m(7)GTP and m(3)(2,2,7)GTP) are, demonstrating the importance of a triphosphate chain for DcpS hydrolytic activity. m(7)GTP and m(3)(2,2,7)GTP are cleaved at a slower rate than their corresponding dinucleotides (m(7)GpppG and m(3)(2,2,7)GpppG, respectively), indicating an involvement of the second nucleoside for efficient DcpS-mediated digestion. Although DcpS enzymes cannot hydrolyze m(7)GDP, they have a high binding affinity for m(7)GDP and m(7)GDP potently inhibits DcpS hydrolysis of m(7)GpppG, suggesting that m(7)GDP may function as an efficient DcpS inhibitor. Our data have important implications for the regulatory role of m(7)GDP in mRNA metabolic pathways due to its possible interactions with different cap-binding proteins, such as DcpS or eIF4E.

Clarke ND et al. (1998) Science "Zinc fingers in Caenorhabditis elegans: finding families and probing pathways."

Berg JM, Clarke ND

[Science, 1998]

More than 3 percent of the protein sequences inferred from the Caenorhabditis elegans genome contain sequence motifs characteristic of zinc-binding structural domains, and of these more than half are believed to be sequence-specific DNA-binding proteins. The distribution of these zinc-binding domains among the genomes of various organisms offers insights into the role of zinc-binding proteins in evolution. In addition, the complete genome sequence of C. elegans provides an opportunity to analyze, and perhaps predict, pathways of transcriptional regulation.AD - Department of Biophysics and Biophysical Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.FAU - Clarke, N DAU - Clarke NDFAU - Berg, J MAU - Berg JMLA - engPT - Journal ArticlePT - ReviewPT - Review, TutorialCY - UNITED STATESTA - ScienceJID - 0404511RN - 0 (DNA-Binding Proteins)RN - 0 (Helminth Proteins)RN - 0 (Membrane Proteins)RN - 0 (Receptors, Cell Surface)RN - 0 (Trans-Activators)RN - 0 (Transcription Factors)RN - 0 (erythroid-like transcription factor 1)RN - 0 (tra-1 protein, Caenorhabditis elegans)SB - IM

O'Connell EM et al. (2015) J Infect Dis "Targeting Filarial Abl-like Kinases: Orally Available, Food and Drug Administration-Approved Tyrosine Kinase Inhibitors Are Microfilaricidal and Macrofilaricidal."

Nutman TB, O'Connell EM, Bennuru S, Steel C, Dolan MA

[J Infect Dis, 2015]

BACKGROUND: Elimination of onchocerciasis and lymphatic filariasis is targeted for 2020. Given the coincident Loa loa infections in Central Africa and the potential for drug resistance development, the need for new microfilaricides and macrofilaricides has never been greater. With the genomes of L. loa, Onchocerca volvulus, Wuchereria bancrofti, and Brugia malayi available, new drug targets have been identified. METHODS: The effects of the tyrosine kinase inhibitors imatinib, nilotinib, and dasatinib on B. malayi adult males, adult females, L3 larvae, and microfilariae were assessed using a wide dose range (0-100 M) in vitro. RESULTS: For microfilariae, median inhibitory concentrations (IC50 values) on day 6 were 6.06 M for imatinib, 3.72 M for dasatinib, and 81.35 M for nilotinib; for L3 larvae, 11.27 M, 13.64 M, and 70.98 M, respectively; for adult males, 41.6 M, 3.87 M, and 68.22 M, respectively; and for adult females, 42.89 M, 9.8 M, and >100 M, respectively. Three-dimensional modeling suggests how these tyrosine kinase inhibitors bind and inhibit filarial protein activity. CONCLUSIONS: Given the safety of imatinib in humans, plans are underway for pilot clinical trials to assess its efficacy in patients with filarial infections.

Johnson TE et al. (1993) Genetics "Absence of strong heterosis for life span and other life history traits in Caenorhabditis elegans."

Hutchinson EW, Johnson TE

[Genetics, 1993]

We have examined crosses between wild-type strains of Caenorhabditis elegans for heterosis effects on life span and other life history traits. Hermaphrodites of all wild strains had similar life expectancies but males of two strains had shorter life spans than hermaphrodites while males of two other strains lived longer than hermaphrodites. F1 hermaphrodite progeny showed no heterosis while some heterosis for longer life span was detected in F1 males. F1 hybrids of crosses between two widely studied wild-type strains, N2 (var. Bristol) and Berg BO (var. Bergerac), were examined for rate of development, hermaphrodite fertility, and behavior; there was no heterosis for these life history traits. Both controlled variation of temperature and uncontrolled environmental variation affected the length of life of all genotypes. Significant G x E effects on life span were observed in comparisons of N2 and Berg BO hermaphrodites, or N2 hermaphrodites and males, or N2 and a Ts mutant strain (DH26). Nevertheless, within an experiment, environmental variation was minimal and life spans were quite replicable.

Wood WB (1976) Worm Breeder's Gazette "maternal effects among ts zygote-defective (zyg) mutants."

Wood WB

[Worm Breeder's Gazette, 1976]

We have studied maternal effects in 23 zyg ts mutants to estimate the times of expression of genes whose products are required in embryogenesis. We have used the following three tests, called arbitrarily A, B, and C. A test: Heterozygous (m/+) L4's are shifted to 25 C and allowed to self-fertilize. If 100% of their eggs yield larvae (25% of which express the mutant phenotype as adults), then the mutant is scored as maternal (M). If 25% of the F1 eggs fail to hatch, then the mutant is scored as non-maternal (N). An M result indicates that expression of the + allele in the parent allows m/m zygotes to hatch and grow to adulthood. A result of N indicates the opposite: that the + allele must be expressed in the zygote for hatching to occur. Out of 23 zyg mutants tested, 3 were scored N and 20 were scored M in the A test. Therefore, for most of the genes defined by these mutants, expression in the parent is sufficient for zygote survival, even if the gene is not expressed in the zygote. B test: Homozygous (m/m) hermaphrodites reared at 25 C are mated with N2 (+/+) males. If eggs fail to hatch at 25 C, but mated hermaphrodites shifted to 16 C produce cross progeny to give proof of mating, then the mutant is scored M. If cross progeny appear in the 25 C mating, then the mutant is scored N. An M result indicates that expression of the + allele in the zygote is not sufficient to allow m/+ progeny of an m/m hermaphrodite to survive. Conversely an N result indicates either that zygotic expression of the + allele is sufficient for survival, or that a sperm function or factor needed for early embryogenesis can be supplied paternally (see C test below). Out of the 23 zyg mutants tested, 11 were scored M and 12 were scored N. The combined results of A and B tests and their simplest interpretation are as follows. Ten mutants are M,M; the genes defined by these mutants must be expressed in the hermaphrodite parent for the zygote to survive. Ten mutants are M,N; these genes can be expressed either in the parent or in the zygote. Two mutants are N,N; these genes must be expressed in the zygote. One mutant is N,M; this gene must be expressed both in the maternal parent and in the zygote. C test: Homozygous (m/m) hermaphrodites reared at 25 C are mated with heterozygous (m/+) males. If rescue by a +/+ male in the B test depends on the + allele, then only half the cross progeny zygotes of a C test mating (m/+ male x m/m hermaphrodite) should survive. However, if rescue depends on a function or cytoplasmic component from the male sperm, then all the cross progeny zygotes in a C test should survive. Of the 10 M,N mutants, 6 have been C tested; one exhibited paternal rescue independent of the + allele. The A and B tests also were carried out on 16 mutants that arrest before the L3 molt (acc mutants). In the A test on 2 of these mutants, all m/m progeny of m/+ parents grew to adulthood at 25 C. Therefore, parental contributions are sufficient to overcome a progeny mutational block as late as the L2 stage. All 16 acc mutants scored N in the B test.

Ali Khan L et al. (1994) Worm Breeder's Gazette "cej-1 Encodes a Novel Protein With Poly-Threonine Motif"

Siddiqui SS, Fukushige T, Ali Khan L, Tsukita Sh, Tabish M, Itoh M

[Worm Breeder's Gazette, 1994]

cej-1 Encodes a Novel Protein with Poly-Threonine Motif M. L. A. Khanl, M. Tabish, T. Fukushigel1 S. Tsukita2, M. Itoh , Sh. Tsukita , and S. S. Siddiqui. (1): Lab. of Molecular Biology, Dept of Ecological Engg. Toyohashi Univ. Technology, Toyohashi 441, and (2). National Institute for Physiological Sciences, Okazaki 444, Japan.

Lemire BD et al. (2009) Mech Ageing Dev "C. elegans longevity pathways converge to decrease mitochondrial membrane potential."

Behrendt M, Decorby A, Lemire BD, Gaskova D

[Mech Ageing Dev, 2009]

Energy production via oxidative phosphorylation generates a mitochondrial membrane potential (DeltaPsi(m)) across the inner membrane. In this work, we show that a lower DeltaPsi(m) is associated with increased lifespan in Caenorhabditis elegans. The long-lived mutants daf-2(e1370), age-1(hx546), clk-1(qm30), isp-1(qm150) and eat-2(ad465) all have a lower DeltaPsi(m) than wild type animals. The lower DeltaPsi(m) of daf-2(e1370) is daf-16 dependent, indicating that the insulin-like signaling pathway not only regulates lifespan but also mitochondrial energetics. RNA interference (RNAi) against 17 genes shown to extend lifespan also decrease DeltaPsi(m). Furthermore, lifespan can be significantly extended with the uncoupler carbonylcyanide-3-chlorophenylhydrazone (CCCP), which dissipates DeltaPsi(m). We conclude that longevity pathways converge on the mitochondria and lead to a decreased DeltaPsi(m). Our results are consistent with the 'uncoupling to survive' hypothesis, which states that dissipation of the DeltaPsi(m) will extend lifespan.

Seo J et al. (2005) Arch Environ Contam Toxicol "Biodegradation of the insecticide N,N-diethyl-m-toluamide by fungi: identification and toxicity of metabolites."

Kim SD, Cha CJ, Hur HG, Lee YG, Seo J, Ahn JH

[Arch Environ Contam Toxicol, 2005]

Fungi (Cunninghamella elegans ATCC 9245, Mucor ramannianus R-56, Aspergillus niger VKMF-1119, and Phanerochaete chrysosporium BKMF-1767) were tested to elucidate the biologic fate of the topical insect repellent N,N-diethyl-m-toluamide (DEET). The elution profile obtained from analysis by high-pressure liquid chromatography equipped with a reverse-phase C-18 column, showed that three peaks occurred after incubation of C. elegans, with which 1 mM DEET was combined as a final concentration. The peaks were not detected in the control experiments with either DEET alone or tested fungus alone. The metabolites produced by C. elegans exhibited a molecular mass of 207 with a fragment ion (m/z) at 135, a molecular mass of 179 with an m/z at 135, and a molecular mass of 163 with an m/z at 119, all of which correspond to N,N-diethyl-m-toluamide-N-oxide, N-ethyl-m-toluamide-N-oxide, and N-ethyl-m-toluamide, respectively. M. ramannianus R-56 also produced N, N-diethyl-m-toluamide-N-oxide and N-ethyl-m-toluamide but did not produce N-ethyl-m-toluamide-N-oxide. For the biologic toxicity test with DEET and its metabolites, the freshwater zooplankton Daphnia magna was used. The biologic sensitivity in decreasing order was DEET > N-ethyl-m-toluamide > N,N-diethyl-m-toluamide-N-oxide. Although DEET and its fungal metabolites showed relatively low mortality compared with other insecticides, the toxicity was increased at longer exposure periods. These are the first reports of the metabolism of DEET by fungi and of the biologic toxicity of DEET and its fungal metabolites to the freshwater zooplankton D. magna.