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[
International C. elegans Meeting,
2001]
Mammalian flavin-containing monooxygenases (FMOs) have been traditionally characterised as "drug-metabolizing enzymes" as they catalyze the oxidative metabolism of numerous xenobiotics, including drugs and pesticides, as well as dietary-derived compounds, eg. trimethylamine (TMA). Of the five mammalian FMOs (FMOs 1-5), the most relevant with respect to human foreign compound metabolism is considered to be FMO3. Loss-of-function mutations in the corresponding gene, FMO3 , underlie "fish-odor syndrome" - an inherited defect in TMA N -oxidation. However, FMOs may play a physiological role in biogenic amine homeostasis as suggested by their expression in the central nervous system and their ability to metabolize biogenic amines in vitro . Biogenic amines have known potent neuromodulatory activities and we hypothesize that their inactivation may, in part, be mediated via FMO action. To further explore this potential role, we are investigating the function of homologous FMOs in C. elegans . The C. elegans genome contains seven predicted genes encoding products exhibiting significant (26-45% amino acid identities) with mammalian FMOs. We have isolated and sequenced cDNAs encoding six of these seven putative worm FMOs and, apart from some minor mistakes, the predicted exon-intron organization of the corresponding genes were found to be correct. The deduced amino acid sequences exhibit predicted hydrophilicity profiles and secondary structure features very similar to those predicted for mammalian FMOs. All mammalian FMOs also contain two copies of a consensus "fingerprint" predicting a Rossman fold characteristic of a binding domain for the ADP moiety of dinucleotides. One such ADP domain is located close to the N -terminal and binds FAD while the other is located further towards the C -terminal and binds NADP. Two such domains are also present in each C. elegans FMO at the same relative locations as they are found in mammalian FMOs. To investigate potential physiological role(s) for the putative C. elegans FMOs we are attempting to create mutant lines for each FMO gene using an adaptation of the TILLING (Targeting Induced Local Lesions IN Genomes) procedure developed originally in Arabidopsis . Single F1 L4 larvae, originating from a synchronised EMS-mutagenised P0 population, are transferred to individual wells of flat-bottomed 96-well plates and cultured for 1 week. Half of the resulting F2 progeny of each F1 worm are then frozen and the remainder used for DNA isolation. PCR, designed to amplify a targeted region of the gene of interest, is performed in 96-well plates and the resulting amplicons are subjected to DHPLC to identify heteroduplexes indicative of a potential mutation within the amplified region. Direct sequencing of the original PCR product identifies the location and nature of the sequence change and, if appropriate, the corresponding frozen F2 worms can then be recovered and mutant lines generated.
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[
Elife,
2020]
Worms with increased levels of the epigenetic mark H3K9me2 have a longer lifespan that can be passed down to future generations.
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[
Curr Top Dev Biol,
2017]
PAR-1/MARK kinases are conserved serine/threonine kinases that are essential regulators of cell polarity. PAR-1/MARK kinases localize and function in opposition to the anterior PAR proteins to control the asymmetric distribution of factors in a wide variety polarized cells. In this review, we discuss the mechanisms that control the localization and activity of PAR-1/MARK kinases, including their antagonistic interactions with the anterior PAR proteins. We focus on the role PAR-1 plays in the asymmetric division of the Caenorhabditis elegans zygote, in the establishment of the anterior/posterior axis in the Drosophila oocyte and in the control of microtubule dynamics in mammalian neurons. In addition to conserved aspects of PAR-1 biology, we highlight the unique ways in which PAR-1 acts in these distinct cell types to orchestrate their polarization. Finally, we review the connections between disruptions in PAR-1/MARK function and Alzheimer's disease and cancer.
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[
Worm Breeder's Gazette,
1994]
DNA fingerprinting in C. elegans - an approach Mark Beneckea, Jorg T. Epplenb and Einhard Schierenberga a Zoologisches Institut der Univeritat, 50923 Koln, Germany b Ruhr-Universitat, Ab1. fur Molekulare Humangenetik, 44780 Bochum, Germany
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[
Sci Rep,
2016]
Adapters bind motor proteins to cargoes and therefore play essential roles in Kinesin-1 mediated intracellular transport. The regulatory mechanisms governing adapter functions and the spectrum of cargoes recognized by individual adapters remain poorly defined. Here, we show that cargoes transported by the Kinesin-1 adapter FEZ1 are enriched for presynaptic components and identify that specific phosphorylation of FEZ1 at its serine 58 regulatory site is mediated by microtubule affinity-regulating kinases (MARK/PAR-1). Loss of MARK/PAR-1 impairs axonal transport, with adapter and cargo abnormally co-aggregating in neuronal cell bodies and axons. Presynaptic specializations are markedly reduced and distorted in FEZ1 and MARK/PAR-1 mutants. Strikingly, abnormal co-aggregates of unphosphorylated FEZ1, Kinesin-1 and its putative cargoes are present in brains of transgenic mice modelling aspects of Alzheimer's disease, a neurodegenerative disorder exhibiting impaired axonal transport and altered MARK activity. Our findings suggest that perturbed FEZ1-mediated synaptic delivery of proteins arising from abnormal signalling potentially contributes to the process of neurodegeneration.
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[
Mol Cell,
2013]
In this issue of Molecular Cell, Castellano-Pozo etal. (2013) describe a connection between R loop structures and histone 3 S10 phosphorylation (H3S10P), a mark of chromatin compaction. Their results constitute asignificant advance in our understanding of the role of R loops in genomic instability.
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[
Curr Biol,
2010]
The small GTPases Rab5 and Rab7 mark temporally distinct but sequentially connected stages in phagosome maturation, but the mechanism underlying the transition between these stages has been unclear. Recent studies in Caenorhabditis elegans have now uncovered a new protein complex that connects Rab5 to Rab7.
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[
Trends Genet,
2001]
Four recent papers mark a major shift in functional genomic analysis for multicellular organisms. RNA-mediated interference was applied to inactivate individual genes systematically on a genomic scale. These studies subjected a third of the genes in the genome of Caenorhabditis elegans to reverse genetic analysis.
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[
Worm Breeder's Gazette,
1990]
The CGC Bibliography has been translated into a couple of programs other than dBase by various worm people. David Barker and Andy Fire both have sent HyperCard versions to the CGC and Mark Blaxter has sent us a version in FileMaker 2.0. None of these is perfectly up-to-date, so you'll have to be somewhat familiar with the programs to add new references. The data files are available free from the CGC; to get yours, just send a blank 3.5' diskette to Mark Edgley at the CGC with a request letter. In addition, Lew Jacobson has translated the bibliography into a DOS program called Memory Mate and he is willing to distribute the data file to anyone who sends him a blank 5.25' 360 Kb diskette. Memory Mate can be operated as a TSR and called up with a hotkey from the middle of a word processor or other program. Addresses for Mark and Lew can be found in the Subscriber Directory Update in this issue.
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[
Development,
2019]
The MARK/PAR-1 family of kinases are conserved regulators of cell polarity that share a conserved C-terminal kinase-associated domain (KA1). Localization of MARK/PAR-1 kinases to specific regions of the cell cortex is a hallmark of polarized cells. In <i>C. elegans</i> zygotes, PAR-1 localizes to the posterior cortex under the influence of another polarity kinase, aPKC/PKC-3. Here we report that asymmetric localization of PAR-1 protein is not essential, and that PAR-1 kinase activity is also regulated spatially. We find that, as in human MARK1, the PAR-1 KA1 domain is an auto-inhibitory domain that suppresses kinase activity. Auto-inhibition by the KA1 domain functions in parallel with phosphorylation by PKC-3 to suppress PAR-1 activity in the anterior cytoplasm. The KA1 domain also plays an additional role essential for germ plasm maintenance and fertility. Our findings suggest that modular regulation of kinase activity by redundant inhibitory inputs contributes to robust symmetry breaking by MARK/PAR-1 kinases in diverse cell types.