Lee M-H et al. (1997) International C. elegans Meeting "TOWARD THE IDENTIFICATION OF IN VIVO RNA TARGETS OF GLD-1."

Lee M-H, Schedl TB

[International C. elegans Meeting, 1997]

gld-1 is a female germ cell specific tumor suppressor gene that is essential for normal oocyte differentiation and meiotic prophase progression (Francis et al., 1995a,b). GLD-1 is a member of a small family of proteins, including the mouse/human Sam68 and Quaking proteins, that are highly related over an ~ 200 amino acid region which contains a 70 to 100 amino acid RNA binding domain called the KH motif (Jones and Schedl, 1995). Extensive mutational analysis of gld-1 has demonstrated the importance of conserved sequences for its in vivo function. GLD-1 is a cytoplasmic protein and therefore is likely to control mRNA translation or RNA stability in the cytoplasm (Jones et al., 1996). Currently, no obvious RNA targets have been identified from genetic analysis. We have employed a biochemical approach to identify in vivo RNA targets of GLD-1. The strategy is based on the ability of anti GLD-1 antibodies to immunoprecipitate (IP) GLD-1 from a worm lysate and the strong likelihood that GLD-1 present in the lysate is functional and bound to RNAs. GLD-1 was IPed with affinity purified polyclonal antibodies from a cytosol extract of adult hermaphrodites or with rabbit IgG as a control. RNAs co-IP with GLD-1, as well as with rabbit IgG, were converted into cDNAs. Non-specifically trapped RNAs from the GLD-1 IP were eliminated by subtracting cDNAs from the GLD-1 IP with cDNAs from the control IP. The difference product after 4 rounds of subtraction (DP4) was used to screen a Lambda ZAP II cDNA library constructed with the cDNAs from the GLD-1 IP. Duplicate filters were also screened with a probe made from control IP cDNA. Clones that are positive only with the DP4 probe are currently being characterized. Francis et al., 1995a Genetics 139, 579-606; Francis et al., 1995b Genetics 139, 607-630; Jones and Schedl, 1995 Genes Dev. 9, 1491-1504; Jones et al., 1996 Dev. Biol. 180, 165-183. This work was supported by NIH Grant HD25614.

David Weinkove et al. (2002) European Worm Meeting "The roles of developmental arrest, phosphoinositides, Type II PIP kinase and DAF-16 in the larval response to oxidative stress."

David R Jones, David Weinkove, Nullin Divecha, Jonathan R Halstead, Ronald H A Plasterk

[European Worm Meeting, 2002]

Since the appearance of terrestrial oxygen, it has been essential to deal with oxidative stress. For a nematode, the important issue is to lay eggs without germline damage. Rather than study the response in adults, for which it is probably too late to do anything useful, we have investigated how L1 larvae respond (1) developmentally, (2) genetically and (3) biochemically to a burst of hydrogen peroxide.

David R. Bell et al. (2006) European Worm Meeting "The Function of Latrophilin in C. elegans"

S. van der Poel, P.N.R. Usherwood, D. Kendall, J. Davy, A. Ademola, I.R. Duce, D. de Pomerai, David R. Bell, I. R. Mellor

[European Worm Meeting, 2006]

David R. Bell, A. Ademola, J. Davy, S. van der Poel, D. Kendall, P.N.R. Usherwood, I.R. Duce, I. R. Mellor and D. de Pomerai. Black Widow spider venom (BWSV) contains latrotoxins that induce catastrophic neurotransmitter release in mammals, and is known to bind with high affinity to three neural proteins in mammals, including latrophilin. We have investigated C. elegans as a model system for studying the function of these proteins, and their role in regulating neurotransmitter release by latrotoxins.. We have shown that latrophilin is required for the lethality of BWSV in C. elegans by RNAi experiments. We now present data on the characterisation of null mutants of the C. elegans latrophilin, lat-1, illustrating the function of this gene in C. elegans, and show that lat-1 nulls are resistant to emodepside. The expression of latrophilin-GFP constructs is examined, and compared with the phenotypes seen in null mutants. Genetic interactions between endogenous signaling pathways and the lat-1 nulls have been examined by the construction of double mutant worms, revealing novel facets of lat-1 function.

Rand JB et al. (2000) East Coast Worm Meeting "UNC-13 in the C. elegans Nervous System"

Kohn RE, Rand JB, McManus JR, Moulder GL, Duke A, Barstead RJ, Duerr JS

[East Coast Worm Meeting, 2000]

C. elegans unc-13 and its homologues in vertebrates and Drosophila are involved in neurotransmitter release. UNC-13 has several regions homologous to PKC regulatory domains; these domains confer it with calcium, phorbol ester and phospholipid binding properties (Maruyama and Brenner, PNAS 88, 1991). A 5.9kb transcript coding for a 200kDa protein was initially identified (now designated L-R for left and right regions). We have identified two additional types of transcripts. One transcript includes a 1kb novel exon (L-M-R, M for middle region) and another transcript lacks the 5' region included in the other two transcripts (M-R). All three transcripts are identical at the 3' end (R). C. elegans with mutations in the 5' end of the gene (L) alter two types of transcripts (L-R and L-M-R) resulting in an uncoordinated coily phenotype and resistance to the anti-cholinesterease, aldicarb. A 2.7kb deletion near the 3' end (R) (identified by Bob Barstead using PCR analysis) affects all unc-13 transcripts and results in a lethal phenotype. Antibodies recognizing the N-terminal region of UNC-13 (L) label synapses, but not synaptic vesicles, of most or all neurons; many mutations in L and R remove staining with this antibody. Supported by grants from the NIH and OCAST.

Schein JE et al. (1997) International C. elegans Meeting "POSITIONING OF ESSENTIAL GENES IN THE lin-3 - let-60 INTERVAL"

Franz NW, Rose AM, Janke DL, Bilkhu N, Baillie DL, Schein JE

[International C. elegans Meeting, 1997]

The lin-3 - let-60 interval of the right arm of chromosome IV contains thirteen essential gene mutations and 22 overlapping sequenced cosmids. The Sanger Center has nearly finished sequencing the entire interval. Analysis of cosmid sequences shows over one hundred potential coding regions. Of the coding regions with proposed protein function, more than 50% have strong homology to human genes. Most notably, the putative genes include three phosphatases, four protein kinases, a kinesin, and a cluster of histones. C. elegans strains carrying sequenced cosmids (in extrachromosomal arrays) have been constructed (see abstract for D. Janke et al., this meeting) and will be used in rescue experiments involving the essential genes in this interval. lin-3 and let-60(ras), the two genes bracketing this interval, were previously placed on the physical map by others. One of the remaining eleven essential genes has been already positioned to a cosmid: let-70(ubc2) (in collaboration with Mei Zhen and Peter Candido). By the time of the meeting, we anticipate that several of the remaining mutations will have been positioned to cosmids. This work is being funded by a grant from the Medical Research Council to Ann Rose and David Baillie and by a grant from the Natural Sciences & Engineering Research Council to David Baillie.

James F Cregg et al. (2004) West Coast Worm Meeting "A RNAi Screen for Genes Involved in Tolerance to Nicotine"

Kathleen B Quast, Kevin J Ford, William R Schafer, James F Cregg, Caroline R Craig, Suchitra Jagannathan

[West Coast Worm Meeting, 2004]

Tobacco use is the second major cause of death worldwide. The acquisition of tolerance to nicotine is a key step in the development of nicotine addiction. Twenty seven nicotinic acetylcholine receptor subunits have been identified in C. elegans (reviewed in Jones and Sattelle, 2003). However, few of the molecules which modify nAChR function, abundance, or subcellular localization in response to nicotine exposure are known. We are performing a RNAi-based screen of the first chromosome using the Ahringer lab RNAi feeding library in a rrf-3 background. In preliminary experiments, worms fed RNAi against genes already known to be involved in nicotine responces (including unc-63 and unc-50) have shown resistance in our nicotine-induced paralysis assay. Results of this screen should provide insight into the mechanisms of nicotine tolerance.

Clifford R et al. (1996) Midwest Worm Meeting "Searching for Proteins that Associate with GLD-1"

Clifford R, Giorgini F, Schedl TB

[Midwest Worm Meeting, 1996]

The gld-1 gene is involved in multiple aspects of C. elegans germline development. The primary, essential function of gld-1 is to direct oogenesis. In the absence of gld-1 activity, germ cells that would otherwise develop into oocytes enter meiosis normally but exit early pachytene to re-enter a mitotic cell cycle and form a tumor. The gene also plays nonessential roles in inhibiting premeiotic germ cell proliferation and promoting germ cells to adopt the male sexual fate [1,2]. gld-1 encodes a 463 amino acid protein that contains an evolutionarily conserved domain of ~200 amino acids that is also found in the mammalian Quaking and Sam68 proteins. A KH RNA binding motif lies within this domain [3]. Since GLD-1 appears to be localized exclusively to the cytoplasm, the protein is likely to regulate mRNA translation or stability [4]. To better understand how gld-1 acts in the control of germline development, we are using the yeast two-hybrid system [5] to isolate proteins that physically associate with the gene product. Through this approach we hope to identify regulators and cofactors of GLD-1. By screening an oligo(dT)-primed cDNA library (gift of R. Barstead) with a fragment of GLD-1 that includes the amino terminal half of the conserved domain, we identified the F28E10.1 gene product as a protein that specifically binds GLD-1. The F28E10.1 locus, which was identified by the C. elegans genome sequencing consortium, is predicted to encode a novel, hydrophilic protein of 118 kD. This gene maps to the region of chromosome IV that is deleted by mDf4 and may correspond to one of the lethal or sterile loci uncovered by the deficiency [6,7]. We are currently testing the biological relevance of the interaction between GLD-1 and F28E10.1 through in vivo assays. Progress will be reported. [1] Francis et al. 1995a. Genetics 139: 579-606; [2] Francis et al. 1995b. Genetics 139: 607-630; [3] Jones and Schedl. 1995. Genes Dev 9: 1491-1504; [4] Jones et al., in preparation; [5] Chien et al. 1991. PNAS 88: 9578-9582; [6] Rogalski and Riddle. 1988. Genetics 118: 61-74; [7] Cassada et al. 1981. Dev Biol 84: 193-205.

Abergel, Z. et al. (2017) International Worm Meeting "Adaptation of the nematode C. elegans to hypoxia and reoxygenation stress reveals an unexpected function of the neuroglobin GLB-5 in innate immunity."

Zuckerman, B., Zelmanovich, V., Abergel, Z., Abergel, R., Gross, E., Smith, Y., Romero, L., Livshits, L.

[International Worm Meeting, 2017]

Deprivation of oxygen (hypoxia) followed by reoxygenation (H/R stress) is a major component in several pathological conditions such as vascular inflammation, myocardial ischemia, and stroke. However how animals adapt and recover from H/R stress remains an open question. Previous studies showed that the neuroglobin GLB-5(Haw) is essential for the fast recovery of the nematode Caenorhabditis elegans (C. elegans) from H/R stress. Here, we characterize the changes in neuronal gene expression during the adaptation of worms to hypoxia and recovery from H/R stress. Our analysis shows that innate immunity genes are differentially expressed during both adaptation to hypoxia and recovery from reoxygenation stress. Moreover, we reveal that the prolyl hydroxylase EGL-9, a known regulator of both adaptation to hypoxia and the innate immune response, inhibits the fast recovery from H/R stress through its activity in the O2-sensing neurons AQR, PQR, and URX. Finally, we show that GLB-5(Haw) acts in AQR, PQR, and URX to increase the tolerance of worms to bacterial pathogenesis. Together, our studies suggest that innate immunity and recovery from H/R stress are regulated by overlapping signaling pathways.

A V Bicknell et al. (2002) European Worm Meeting "The C. elegans F47F2.1 gene encodes a cyclic AMP-dependent protein kinase (PK-A) catalytic subunit"

A V Bicknell, M J Fisher, M Tabish, R A Clegg, H H Rees

[European Worm Meeting, 2002]

PK-A mediates all known effects of cyclic AMP on cellular activity in eukaryotes. The holoenzyme is an inactive tetramer of two regulatory (R) subunits and two catalytic (C) subunits. Following binding of cyclic AMP to the R subunits, dissociation of active C-subunits occurs. In mammals, , and isoforms of C-subunit, encoded by different genes, have been identified.

Angelo RG et al. (1997) International C. elegans Meeting "DISCOVERY OF A POTENTIAL ANCHOR/SCAFFOLD PROTEIN FOR C. ELEGANS PROTEIN KINASE A (PKA)"

Angelo RG, Rubin CS

[International C. elegans Meeting, 1997]

C. elegans PKA is composed exclusively of catalytic and regulatory (R) subunits encoded by the kin-1 and kin-2 genes. Since C. elegans lacks other PKA isoforms, this enzyme must disseminate signals carried by cAMP to all cell compartments. Approximately 60% of total R (PKA) is in the particulate fraction of disrupted C. elegans, indicating that protein/protein interactions may diversify PKA signaling by anchoring the kinase at specific intracellular locations. Co-localization of PKA with upstream activators and/or downstream effectors can create target sites for cAMP action. To understand the mechanism of PKA localization in C. elegans, a cDNA expression library was screened with recombinant radiolabeled-R (0.5 nM) to obtain high-affinity binding proteins. A cDNA encoding a novel, 143 kDa A kinase anchor protein (AKAP1) was retrieved and sequenced. The corresponding gene (rap-1) is located in LGII and contains 17 exons. AKAP1 is an acidic protein (pI=4.4) that is unrelated to previously characterized proteins. C. elegans R is avidly bound by both soluble and immobilized fragments of AKAP1. Competition binding studies indicate that C. elegans R is a preferred ligand, whereas mammalian RII and RI isoforms are only weakly sequestered. Scatchard analysis yielded a Kd value of ~10 nM for the R/AKAP1 complex. Deletion mutagenesis, coupled with protein expression in E. coli and in vitro assays, demonstrated that residues 235 to 255 govern high-affinity binding of R by AKAP1. A hydrophobic surface generated by amino acids with branched aliphatic side chains may be a key determinant of R binding activity. Site directed mutagenesis will pinpoint essential residues involved in PKA binding. Studies aimed at identifying the AKAP1 binding site on R are also in progress. High-affinity anti-AKAP1 IgGs are being used to determine (a) whether AKAP1 expression is developmentally-regulated and cell- specific and (b) the relationship between R (PKA) and AKAP1 in vivo.