Kato T et al. (2007) J Biochem "Unique peptide:N-glycanase of Caenorhabditis elegans has activity of protein disulphide reductase as well as of deglycosylation."

Kawahara A, Yamamoto K, Kato T, Ashida H

[J Biochem, 2007]

Peptide:N-glycanase (PNGase) is the enzyme responsible for de-N-glycosylation of misfolded glycoproteins in the cytosol. Here, we report the molecular identification and characterization of PNGase (png-1, F56G4.5) from Caenorhabditis elegans. This enzyme released both high mannose- and complex-type N-glycans from glycopeptides and denatured glycoproteins. Deglycosylation activity was inhibited by Zn(2+) and z-VAD-fmk, but not by EDTA. PNG-1 has a thioredoxin-like domain in addition to a transglutaminase domain, the core domain of PNGases, and exhibited protein disulfide reductase activity in vitro. Our biochemical studies revealed that PNG-1 is a unique bifunctional protein possessing two enzyme activities.

Kato T et al. (2007) J Biol Chem "Free oligosaccharides in the cytosol of Caenorhabditis elegans are generated through endoplasmic reticulum-golgi trafficking."

Yamamoto K, Kato T, Kitamura K, Katayama T, Kimura Y, Ashida H, Maeda M

[J Biol Chem, 2007]

Free oligosaccharides (FOS) in the cytosol of eukaryotic cells are mainly generated during endoplasmic reticulum-associated degradation (ERAD) of misfolded glycoproteins. We analyzed FOS of the nematode Caenorhabditis elegans to elucidate its detailed degradation pathway. The major FOS were high mannose-type ones bearing 3-9 Man residues. About 94% of the total FOS had one GlcNAc at their reducing end (FOS-GN1) and the remaining 6% had two GlcNAc (FOS-GN2). A cytosolic endo-ss-N-acetylglucosaminidase mutant (tm1208) accumulated FOS-GN2, indicating involvement of the enzyme in conversion of FOS-GN2 into FOS-GN1. The most abundant FOS in the wild type was Man(5)GlcNAc(1), the M5A'' isomer [Mana1-3(Mana1-6)Mana1-6(Mana1-3)Manss1-4GlcNAc] which is different from the corresponding M5B'' [Mana1-2Mana1-2Mana1-3(Mana1-6)Manss1-4GlcNAc] in mammals. Analyses of FOS in worms treated with Golgi a-mannosidase I inhibitors revealed decreases in Man(5)GlcNAc(1) and increases in Man(7)GlcNAc(1). These results suggested that Golgi a-mannosidase I-like enzyme is involved in the production of Man(5-6)GlcNAc(1), which is unlike in mammals, in which cytosolic a-mannosidase is involved. Thus, we assumed that major FOS in C. elegans were generated through Golgi trafficking. Analysis of FOS from a Golgi a-mannosidase II mutant (tm1078) supported this idea, because GlcNAc(1)Man(5)GlcNAc(1), which is formed by the Golgi-resident GlcNAc-transferase I, was found as a FOS in the mutant. We concluded that significant amounts of misfolded glycoproteins in C. elegans are trafficked to the Golgi and are directly or indirectly retro-translocated into the cytosol to be degraded.

Kato T et al. (2002) Glycobiology "Identification of an endo-beta-N-acetylglucosaminidase gene in Caenorhabditis elegans and its expression in Escherichia coli."

Kumagai H, Ikura K, Fujita K, Kato T, Natsuka S, Kobayashi K, Yamamoto K, Takeuchi M

[Glycobiology, 2002]

We report the identification, molecular cloning, and characterization of an endo-beta-N-acetylglucosaminidase from the nematode Caenorhabditis elegans. A search of the C. elegans genome database revealed the existence of a gene exhibiting 34% identity to Mucor hiemalis (a fungus) endo-beta-N-acetylglucosaminidase (Endo-M). Actually, the C. elegans extract contained endo-beta-N-acetylglucosaminidase activity. The putative cDNA for the C. elegans endo-beta-N-acetylglucosaminidase (Endo-CE) was amplified by polymerase chain reaction from the Uni-ZAP XR library, cloned, and sequenced. The recombinant Endo-CE expressed in Escherichia coli exhibited substrate specificity mainly for high-mannose type oligosaccharides. Man8GlcNAc2 was the best substrate for Endo-CE, and Man3GlcNAc2 was also hydrolyzed. Biantennary complex type oligosaccharides were poor substrates, and triantennary complex substrates were not hydrolyzed. Its substrate specificity was similar to those of Endo-M and endo-beta-N-acetylglucosaminidase from hen oviduct. Endo-CE was confirmed to exhibit transglycosylation activity, as seen for some microbial endo-beta-N-acetylglucosaminidases. This is the first report of the molecular cloning of an endo-beta-N-acetylglucosaminidase gene from a multicellular organism, which shows the possibility of using this well-characterized nematode as a model system for elucidating the role of this enzyme.

Branson K et al. (2015) Cell "Imaging the neural basis of locomotion."

Branson K, Freeman J

[Cell, 2015]

To investigate the fundamental question of how nervous systems encode, organize, and sequence behaviors, Kato etal. imaged neural activity with cellular resolution across the brain of the worm Caenorhabditis elegans. Locomotion behavior seems to be continuously represented by cyclical patterns of distributed neural activity that are present even in immobilized animals.

Samuel ADT et al. (2003) J Neurosci "Synaptic activity of the AFD neuron in Caenorhabditis elegans correlates with thermotactic memory."

Murthy VN, Samuel ADT, Silva RA

[J Neurosci, 2003]

Thermotactic behavior in Caenorhabditis elegans is sensitive to both a worm's ambient temperature (T-amb) and its memory of the temperature of its cultivation (T-cult). The AFD neuron is part of a neural circuit that underlies thermotactic behavior. By monitoring the fluorescence of pH-sensitive green fluorescent protein localized to synaptic vesicles, we measured the rate of the synaptic release of AFD in worms cultivated at temperatures between 15 and 25degreesC, and subjected to fixed, ambient temperatures in the same range. We found that the rate of AFD synaptic release is high if either T-amb > T-cult or T-amb > T-cult, but AFD synaptic release is low if T-amb congruent to T-cult. This suggests that AFD encodes a direct comparison between T-amb and T-cult.

Bommireddy R et al. (2007) Trends Mol Med "TGFbeta1 and Treg cells: alliance for tolerance."

Bommireddy R, Doetschman T

[Trends Mol Med, 2007]

Transforming growth factor beta1 (TGFbeta1), an important pleiotropic, immunoregulatory cytokine, uses distinct signaling mechanisms in lymphocytes to affect T-cell homeostasis, regulatory T (T(reg))-cell and effector-cell function and tumorigenesis. Defects in TGFbeta1 expression or its signaling in T cells correlate with the onset of several autoimmune diseases. TGFbeta1 prevents abnormal T-cell activation through the modulation of Ca(2+)-calcineurin signaling in a Caenorhabditis elegans Sma and Drosophila Mad proteins (SMAD)3 and SMAD4-independent manner; however, in T(reg) cells, its effects are mediated, at least in part, through SMAD signaling. TGFbeta1 also acts as a pro-inflammatory cytokine and induces interleukin (IL)-17-producing pathogenic T-helper cells (T(h) IL-17 cells) synergistically during an inflammatory response in which IL-6 is produced. Here, we will review TGFbeta1 and its signaling in T cells with an emphasis on the regulatory arm of immune tolerance.

Agulnik SI et al. (1995) Genomics "Conservation of the T-box gene family from Mus musculus to Caenorhabditis elegans."

Bollag RJ, Silver LM, Agulnik SI

[Genomics, 1995]

Recently, a novel family of genes with a region of homology to the mouse T locus, which is known to play a crucial, and conserved, role in vertebrate development, has been discovered. The region of homology has been named the T-box. The T-box domain of the prototypical T locus product is associated with sequence-specific DNA binding activity. In this report, we have characterized four members of the T-box gene family from the nematode Caenorhabditis elegans. All lie in close proximity to each other in the middle of chromosome III. Homology analysis among all completely sequenced T-box products indicates a larger size for the conserved T-box domain (166 to 203 residues) than previously reported. Phylogenetic analysis suggests that one C. elegans T-box gene may be a direct ortholog of the mouse Tbx2 and Drosophila omb genes. The accumulated data demonstrate the ancient nature of the T-box gene family and suggest the existence of at least three separate T-box-containing genes in a common early metazoan ancestor to nematodes and vertebrates.

Ju T et al. (2006) Glycobiology "Identification of core 1 O-glycan T-synthase from Caenorhabditis elegans."

Ju T, Zheng Q, Cummings RD

[Glycobiology, 2006]

The common O-glycan core structure in animal glycoproteins is the core 1 disaccharide Galbeta1-3GalNAcalpha1-Ser/Thr, which is generated by addition of Gal to GalNAcalpha1-Ser/Thr by core 1 UDP-Gal:GalNAcalpha1-Ser/Thr beta1,3-galactosyltransferase (core 1 beta3-Gal-T or T-synthase, EC2.4.1.122)(2). Although O-glycans play important roles in vertebrates, much remains to be learned from model organisms such as the free-living nematode Caenorhabditis elegans, which offer many advantages in exploring O-glycan structure/function. Here we report the cloning and enzymatic characterization of T-synthase from C. elegans (Ce-T-synthase). A putative C. elegans gene for T-synthase, C38H2.2, was identified in GenBank by a BlastP search using the human T-synthase protein sequence. The full-length cDNA for Ce-T-synthase, which was generated by PCR using a C. elegans cDNA library as the template, contains 1,170 bp including the stop TAA. The cDNA encodes a protein of 389 amino acids with typical type-II membrane topology and a remarkable 42.7% identity to the human T-synthase. Ce-T-synthase has 7 Cys residues in the lumenal domain including 6 conserved Cys residues in all of the orthologs. The Ce-T-synthase has 4 potential N-glycosylation sequons, whereas the mammalian orthologs lack N-glycosylation sequons. Only one gene for Ce-T-synthase was identified in the genome-wide search and it contains 8 exons. Promoter analysis of the Ce-T-synthase using green fluorescent protein constructs show that the gene is expressed at all developmental stages and appears to be in all cells. Unexpectedly, only minimal activity was recovered in the recombinant, soluble Ce-T-synthase secreted from a wide variety of mammalian cell lines, whereas robust enzyme activity was recovered in the soluble Ce-T-synthase expressed in Hi-5 insect cells. Vertebrate T-synthase requires the molecular chaperone Cosmc, but our results show that Ce-T-synthase does not require Cosmc, and might require invertebrate-specific factors for formation of the optimally active enzyme. These results show that the Ce-T-synthase is a functional ortholog to the human T-synthase in generating core 1 O-glycans and opens new avenues to explore O-glycan function in this model organism.

Muir RE et al. (2007) Int J Syst Evol Microbiol "Leucobacter chromiireducens subsp. solipictus subsp. nov., a pigmented bacterium isolated from the nematode Caenorhabditis elegans, and emended description of L. chromiireducens."

Muir RE, Tan MW

[Int J Syst Evol Microbiol, 2007]

A yellow-pigmented, Gram-positive, aerobic, non-motile, non-spore-forming, irregular rod-shaped bacterium (strain TAN 31504(T)) was isolated from the bacteriophagous nematode Caenorhabditis elegans. Based on 16S rRNA gene sequence similarity, DNA G+C content of 69.5 mol%, 2,4-diaminobutyric acid in the cell-wall peptidoglycan, major menaquinone MK-11, abundance of anteiso- and iso-fatty acids, polar lipids diphosphatidylglycerol and phosphatidylglycerol and a number of shared biochemical characteristics, strain TAN 31504(T) was placed in the genus Leucobacter. DNA-DNA hybridization comparisons demonstrated a 91 % DNA-DNA relatedness between strain TAN 31504(T) and Leucobacter chromiireducens LMG 22506(T) indicating that these two strains belong to the same species, when the recommended threshold value of 70 % DNA-DNA relatedness for the definition of a bacterial species by the ad hoc committee on reconciliation of approaches to bacterial systematics is considered. Based on distinct differences in morphology, physiology, chemotaxonomic markers and various biochemical characteristics, it is proposed to split the species L. chromiireducens into two novel subspecies, Leucobacter chromiireducens subsp. chromiireducens subsp. nov. (type strain L-1(T)=CIP 108389(T)=LMG 22506(T)) and Leucobacter chromiireducens subsp. solipictus subsp. nov. (type strain TAN 31504(T)=DSM 18340(T)=ATCC BAA-1336(T)).

Agulnik SI et al. (1997) Genome "Three novel T-box genes in Caenorhabditis elegans."

Ruvinsky I, Agulnik SI, Silver LM

[Genome, 1997]

The T-box gene family consists of members that share a unique DNA binding domain. The best characterized T-box gene, Brachyury or T, encodes a transcription factor that plays an important role in early vertebrate development. Seven other recently described mouse T-box genes are also expressed during development. In the nematode Caenorhabditis elegans, four T-box genes have been characterized to date. In this study, we describe three new C. elegans T-box genes, named Ce-tbx-11, Ce-tbx-12, and Ce-tbx-17. Ce-tbx-11 and Ce-tbx-17 were uncovered through the sequencing efforts of the C. elegans Genome Project. Ce-tbx-12 was uncovered through degenerate PCR analysis of C. elegans genomic DNA. Ce-tbx-11 and Ce-tbx-17 are located in close proximity to the four other previously described T-box genes in the central region of chromosome III. In contrast, Ce-tbx-12 maps alone to chromosome II. Phylogenetic analysis of all known T-box domain sequences provides evidence of an ancient origin for this gene family.