Curran S P et al. (2010) Aging, Metabolism, Stress, Pathogenesis, and Small RNAs, Madison, WI "A soma-to-germline character in long-lived Caenorhabditis elegans mutants"

Riedel C, Wu X, Ruvkun G, Curran S P

[Aging, Metabolism, Stress, Pathogenesis, and Small RNAs, Madison, WI, 2010]

Unlike the soma, which ages during the lifespan of multicellular organisms, the germ line traces an essentially immortal lineage. Genomic instability in somatic cells increases with age, and this decline in somatic maintenance might be regulated to facilitate resource reallocation towards reproduction at the expense of cellular senescence. Here we show that Caenorhabditis elegans mutants with increased longevity exhibit a soma-to-germline transformation of gene expression programs normally limited to the germ line. Decreased insulin-like signalling causes the somatic misexpression of the germline-limited pie-1 and pgl family of genes in intestinal and ectodermal tissues. The forkhead boxO1A (FOXO) transcription factor DAF-16, the major transcriptional effector of insulin-like signalling, regulates pie-1 expression by directly binding to the pie-1 promoter. The somatic tissues of insulin-like mutants are more germline-like and protected from genotoxic stress. Gene inactivation of components of the cytosolic chaperonin complex that induce increased longevity also causes somatic misexpression of PGL-1. These results indicate that the acquisition of germline characteristics by the somatic cells of C. elegans mutants with increased longevity contributes to their increased health and survival.

Curran, Tyler S et al. (2013) International Worm Meeting "Giving Light to Sperm-Specific Phosphatases."

Chu, Diana, Mateo, Leslie, Curran, Tyler S

[International Worm Meeting, 2013]

Despite affecting millions in the U.S. alone, male infertility at the molecular level is poorly understood. Phenotypes of male infertility include improperly segregated sperm chromosomes and sperm immotility. For example, in mice these same phenotypes have been linked to defects in a sperm-specific isoform of protein phosphatase one (PP1) isoform, PP1g2. Our research in Caenorhabditis elegans has identified two sperm-specific PP1s GSP-3 and GSP-4, which are 98%; identical. We have shown that GSP-3/4 are functional homologues of PP1g2; targeted deletion of gsp-3/4 genes causes aberrant chromosome segregation during meiosis and immotility in mature sperm. PP1g2 and GSP-3/4 likely do not act alone, as PP1s rely on interacting proteins for catalytic activity and substrate specificity. Thus, many studies focus on individual PP1-protein complexes. While some sperm-specific PP1-protein complexes are starting to be identified, many of the interacting proteins and their functions remain unknown. To that end, we aim to identify the interacting proteins of GSP-3/4 in C. elegans. Previous work has given us candidate interacting proteins of GSP-3/4. Targeted deletions of gsp-3/4 disrupt major sperm protein (MSP) localization, a key protein in sperm motility. In addition, we have shown that GSP-3/4 localization is similar to that of kinetochores during sperm meiotic divisions; thus we expect GSP-3/4 may interact with kinetochore proteins. Our study is generating worms expressing green fluorescent protein (GFP) tagged GSP-3/4 (GSP-3/4::GFP). GFP will allow for live imaging of the enzymes and will also be a target for co-immunoprecipitation (co-IP) of GSP-3/4::GFP and their interacting proteins. Thus far, we have used Gateway Cloning (Invitrogen) to create GSP-3/4::GFP constructs in Mos1 single copy insert (MosSCI) compatible vectors. Using microinjection into MosSCI compatible EG6699 worms we have integrated single copies gsp-4::gfp into genomic DNA. We are currently working to integrate gsp-3::gfp constructs and validate fusion protein function. Our future studies will utilize these strains for the identification of interacting proteins by co-IP, as well as live imaging of GSP-3/4::GFP during spermatogenesis.

Chang JT et al. (2020) Methods Mol Biol "Correction to: Assessing Tissue-Specific Autophagy Flux in Adult Caenorhabditis elegans."

Chang JT, Kumsta C, Hansen M

[Methods Mol Biol, 2020]

Correction to: Chapter 17 in: Sean P. Curran (ed.), Aging: Methods and Protocols, Methods in Molecular Biology, vol. 2144.

Walhout AJ (2014) Cell Metab "Genetic adaptation to diet preserves longevity."

Walhout AJ

[Cell Metab, 2014]

Diet affects cellular metabolism and organismal life history traits. Pang and Curran (2014) use Caenorhabditis elegans and its bacterial diets to unveil genetic perturbations in proline catabolism that shorten lifespan, but, only on specific Escherichia coli diets, thereby unveiling a genome-encoded adaptive response to different nutritional states.

Jones DL (2009) Cell Metab "Walk the (germ) line."

Jones DL

[Cell Metab, 2009]

Germ cells possess the unique ability to transmit genetic information from generation to generation. In a recent paper, Curran et al. (2009) explore the possibility that some features of germ cells, including enhanced genomic stability, can be acquired by the soma as a mechanism to increase longevity.

Vinci CR et al. (2007) J Biol Chem "Recognition of age-damaged (R,S)-adenosyl-L-methionine by two methyltransferases in the yeast Saccharomyces cerevisiae."

Vinci CR, Clarke SG

[J Biol Chem, 2007]

The biological methyl donor, S adenosylmethionine (AdoMet), can exist in two diastereoisomeric states with respect to its sulfonium ion. The "S" configuration, (S,S)AdoMet, is the only form that is produced enzymatically as well as the only form used in almost all biological methylation reactions. Under physiological conditions, however, the sulfonium ion can spontaneously racemize to the "R" form, producing (R,S)AdoMet. As of yet, (R,S)AdoMet has no known physiological function and may inhibit cellular reactions. In this study, two enzymes have been found in Saccharomyces cerevisiae that are capable of recognizing (R,S)AdoMet and using it to methylate homocysteine to form methionine. These enzymes are the products of the SAM4 and MHT1 genes, previously identified as homocysteine methyltransferases dependent upon AdoMet and S-methylmethionine respectively. We find here that Sam4 recognizes both (S,S) and (R,S)AdoMet, but its activity is much higher with the R,S form. Mht1 reacts with only the R,S form of AdoMet while no activity is seen with the S,S form. R,S-specific homocysteine methyltransferase activity is also shown here to occur in extracts of Arabidopsis thaliana, Drosophila melanogaster, and Caenorhabditis elegans, but has not been detected in several tissue extracts of Mus musculus. Such activity may function to prevent the accumulation of (R,S)AdoMet in these organisms.

Fanning S et al. (2018) Mol Cell "Lipidomic Analysis of -Synuclein Neurotoxicity Identifies Stearoyl CoA Desaturase as a Target for Parkinson Treatment."

Lou Y, Haque A, Freyzon Y, Farese RV, Terry-Kantor E, Hofbauer HF, Termine D, Welte MA, Barrasa MI, Imberdis T, Noble T, Lindquist S, Clish CB, Jaenisch R, Pincus D, Nuber S, Sandoe J, Kohlwein SD, Kim TE, Ho GPH, Ramalingam N, Walther TC, Baru V, Selkoe D, Srinivasan S, Landgraf D, Soldner F, Dettmer U, Fanning S, Becuwe M, Newby G

[Mol Cell, 2018]

In Parkinson's disease (PD), -synuclein (S) pathologically impacts the brain, a highly lipid-rich organ. We investigated how alterations in S or lipid/fattyacid homeostasis affect each other. Lipidomic profiling of human S-expressing yeast revealed increases in oleic acid (OA, 18:1), diglycerides, and triglycerides. These findings were recapitulated in rodent and human neuronal models of S dyshomeostasis (overexpression; patient-derived triplication or E46K mutation; E46K mice). Preventing lipid droplet formation or augmenting OA increased S yeast toxicity; suppressing the OA-generating enzyme stearoyl-CoA-desaturase (SCD) was protective. Genetic or pharmacological SCD inhibition ameliorated toxicity in S-overexpressing rat neurons. In a C.elegans model, SCD knockout prevented S-induced dopaminergic degeneration. Conversely, we observed detrimental effects of OA on S homeostasis: in human neural cells, excess OA caused S inclusion formation, which was reversed by SCD inhibition. Thus, monounsaturated fatty acid metabolism is pivotal for S-induced neurotoxicity, and inhibiting SCD represents a novel PD therapeutic approach.

Turner, C. et al. (2019) International Worm Meeting "Loss of O-GlcNacyation Supresses the Activity of a skn-1 Gain-of-Fucnction Mutant."

Curran, S., Turner, C., Pratt, M.

[International Worm Meeting, 2019]

Recently SKN-1 activity was shown to be dependent on the post translational modification O-linked-N-Acetylglucosamine. Here we seek to determine the capacity of this known regulator to influence the activity of a constitutively activated variant of SKN-1. Using genetic nulls of the O-GlcNAc cycling enzymes ogt-1and oga-1, we find that a loss of ogt-1results in an attenuation of SKN-1 gain-of-function phenotypes. Using transcriptomic analysis we find a reduced expression of oxidative stress response genes, while Oil-Red-O lipid staining reveals an attenuation of soma to germline lipid reallocation in late life. These findings demonstrate that this gain-of-function variant of SKN-1 can still be influenced by known regulatory pathways.

Vandecandelaere I et al. (2017) PLoS One "Metabolic activity, urease production, antibiotic resistance and virulence in dual species biofilms of Staphylococcus epidermidis and Staphylococcus aureus."

Deforce D, Coenye T, Van Nieuwerburgh F, Vandecandelaere I

[PLoS One, 2017]

In this paper, the metabolic activity in single and dual species biofilms of Staphylococcus epidermidis and Staphylococcus aureus isolates was investigated. Our results demonstrated that there was less metabolic activity in dual species biofilms compared to S. aureus biofilms. However, this was not observed if S. aureus and S. epidermidis were obtained from the same sample. The largest effect on metabolic activity was observed in biofilms of S. aureus Mu50 and S. epidermidis ET-024. A transcriptomic analysis of these dual species biofilms showed that urease genes and genes encoding proteins involved in metabolism were downregulated in comparison to monospecies biofilms. These results were subsequently confirmed by phenotypic assays. As metabolic activity is related to acid production, the pH in dual species biofilms was slightly higher compared to S. aureus Mu50 biofilms. Our results showed that S. epidermidis ET-024 in dual species biofilms inhibits metabolic activity of S. aureus Mu50, leading to less acid production. As a consequence, less urease activity is required to compensate for low pH. Importantly, this effect was biofilm-specific. Also S. aureus Mu50 genes encoding virulence-associated proteins (Spa, SplF and Dps) were upregulated in dual species biofilms compared to monospecies biofilms and using Caenorhabditis elegans infection assays, we demonstrated that more nematodes survived when co-infected with S. epidermidis ET-024 and S. aureus mutants lacking functional spa, splF or dps genes, compared to nematodes infected with S. epidermidis ET-024 and wild- type S. aureus. Finally, S. epidermidis ET-024 genes encoding resistance to oxacillin, erythromycin and tobramycin were upregulated in dual species biofilms and increased resistance was subsequently confirmed. Our data indicate that both species in dual species biofilms of S. epidermidis and S. aureus influence each other's behavior, but additional studies are required necessary to elucidate the exact mechanism(s) involved.

Vandecandelaere I et al. (2014) Pathog Dis "Protease production by Staphylococcus epidermidis and its effect on Staphylococcus aureus biofilms."

Coenye T, Vandecandelaere I, Depuydt P, Nelis HJ

[Pathog Dis, 2014]

Due to the resistance of Staphylococcus aureus to several antibiotics, treatment of S. aureus infections is often difficult. As an alternative to conventional antibiotics, the field of bacterial interference is investigated. Staphylococcus epidermidis produces a serine protease (Esp) which inhibits S. aureus biofilm formation and which degrades S. aureus biofilms. In this study, we investigated the protease production of 114 S. epidermidis isolates, obtained from biofilms on endotracheal tubes (ET). Most of the S. epidermidis isolates secreted a mixture of serine, cysteine and metalloproteases. We found a link between high protease production by S. epidermidis and the absence of S. aureus in ET biofilms obtained from the same patient. Treating S. aureus biofilms with the supernatant (SN) of the most active protease producing S. epidermidis isolates resulted in a significant biomass decrease compared to untreated controls, while the number of metabolically active cells was not affected. The effect on the biofilm biomass was mainly due to serine proteases. Staphylococcus aureus biofilms treated with the SN of protease producing S. epidermidis were thinner with almost no extracellular matrix. An increased survival of Caenorhabditis elegans, infected with S. aureus Mu50, was observed when the SN of protease positive S. epidermidis was added.