Carmona, Juan J. et al. (2009) International Worm Meeting "The C. elegans PNC-1 nicotinamidase increases stress resistance and mediates caloric restriction-induced longevity."

Hanna-Rose, Wendy, Vrablik, Tracy, Sleigh, James N., Carmona, Juan J., Hart, Anne C., Sinclair, David A., Michan, Shaday

[International Worm Meeting, 2009]

A common and powerful non-genetic method used to extend an organism''s lifespan is caloric restriction, yet the underlying molecular mechanisms of this increased longevity remain unclear. In yeast, Pnc1 (nicotinamidase), an enzyme in the NAD+ salvage pathway that converts nicotinamide to nicotinic acid to assist in regenerating NAD+, can mediate lifespan extension under caloric restriction and mild stresses. We have previously shown that Pnc1 is nuclear, cytoplasmic, and peroxisomal in yeast and that caloric restriction and stress, like salt, causes a significant up-regulation in expression (Anderson, 2003). To understand the impact of this nicotinamidase on longevity and stress resistance in multi-cellular organisms, we are using C. elegans as a model. We show that the worm ortholog PNC-1 also has robust nicotinamidase activity in vitro and that increased gene dosage in C. elegans protects against salt stress and extends lifespan. Interestingly, this longevity effect is sirtuin dependent. In addition, lifespan extension mediated by PNC-1 over-expression is not additive with caloric restriction-induced longevity, suggesting that PNC-1 is an important component of this pathway. Accordingly, inactivation of the pnc-1 gene leads to a defect in caloric restriction-induced longevity in C. elegans. Using a GFP reporter, we found that pnc-1 is expressed in the pharynx and nervous system, including the chemosensory ASK neurons. We are currently using cell-specific promoters to dissect the biological relevance of these sites of expression. Interestingly, invertebrate PNC-1 and the mammalian PBEF/Visfatin catalyze analogous biochemical steps; we are expressing the human PBEF/Visfatin in pnc-1 loss-of-function animals to test the functional conservation of these enzymes across species. Collectively, this study elucidates a functional role for PNC-1 in metazoans and expands our understanding of conserved pathways involved in longevity and stress resistance across organisms.

Juan J. Carmona et al. (2007) International Worm Meeting "Functional Characterization of pnc-1 in C. elegans."

Juan J. Carmona, David A. Sinclair, Anne C. Hart

[International Worm Meeting, 2007]

In yeast, Pnc1 (nicotinamidase), an enzyme in the NAD+ salvage pathway that converts nicotinamide to nicotinic acid to assist in regenerating NAD+, has been shown to be necessary and sufficient for lifespan extension under caloric restriction and mild stresses. Furthermore, a Pnc1-GFP fusion reporter has shown that Pnc1 is nuclear, cytoplasmic, and peroxisomal in yeast and that caloric restriction and mild stress, like heat, causes a significant increase in fluorescence intensity. Given these data, therefore, attention has now turned to Pnc1 homologues in multi-cellular organisms, such as PNC-1 in C. elegans, specifically with the desire to study functional conservation of this enzyme with respect to longevity and stress pathways. Recently, it has been reported that RNAi-mediated knockdown of the C. elegans homologue pnc-1 significantly decreases adult lifespan and that increased gene dosage enhances survival during oxidative stress treatment. However, the tissue-specific expression pattern of PNC-1 remains unknown and a protective role for PNC-1 during heat shock, a common stress paradigm in C. elegans, has not been considered. To this end, we have generated GFP fusion constructs to pinpoint PNC-1 expression. Upon first examination, GFP is expressed in pharyngeal muscle and ASK neurons, with the latter playing a role in insulin signaling and longevity. Furthermore, we have generated polyclonal antibodies against PNC-1 and have determined by Western blot that stresses, in particular heat, increase PNC-1 protein levels. Finally, we have produced PNC-1 over-expressing lines which we are actively characterizing for a longevity phenotype. Our preliminary data suggest that these over-expressing lines are markedly thermotolerant; other forms of stress are under analysis. Collectively, it is anticipated that all of these studies will help to elucidate a functional role for pnc-1 in animals, to further expand our understanding of conserved longevity and stress pathways across organisms.

McGhee JD (1987) Biochemistry "Purification and characterization of a carboxylesterase from the intestine of the nematode Caenorhabditis elegans."

McGhee JD

[Biochemistry, 1987]

The major intestinal esterase from the nematode Caenorhabditis elegans has been purified to essential homogeneity. Starting from whole worms, the overall purification is 9000-fold with a 10% recovery of activity. The esterase is a single polypeptide chain of Mr 60,000 and is stoichiometrically inhibited by organophosphates. Substrate preferences and inhibition patterns classify the enzyme as a carboxylesterase (EC 3.1.1.1), but the physiological function is unknown. The sequence of 13 amino acid residues at the esterase N- terminus has been determined. This partial sequence shows a surprisingly high degree of similarity to the N-terminal sequence of two carboxylesterases recently isolated from Drosophila mojavensis [Pen, J., van Beeumen, J., & Beintema, J. J. (1986) Biochem. J. 238, 691-699].

Murakami S et al. (1999) Curr Biol "Life extension and stress resistance in Caenorhabditis elegans modulated by the tkr-1 gene."

Johnson TE, Murakami S

[Curr Biol, 1999]

In this Brief Communication, which appeared in the 14 September 1998 issue of Current Biology, the UV dose was reported erroneously. The dose reported was 20 J/m2 but the actual dose used was 0.4 J/cm2. Also, the gene formally referred to as tkr-1 has since been renamed old-1 (overexpression longevity determination).

Ramos CG et al. (2014) J Bacteriol "Retraction for Ramos et al., MtvR is a global small noncoding regulatory RNA in Burkholderia cenocepacia."

Feliciano JR, da Costa PJ, Ramos CG, Grilo AM, Leitao JH

[J Bacteriol, 2014]

Volume 195, no. 16, p. 35143523, 2013. A number of problems related to images published in this paper have been brought to our attention. Figure 1D contains duplicated images in lanes S and LE, and Fig. 4D and 6B contain images previously published in articles in this journal and in Microbiology and Microbial Pathogenesis, i.e., the following: C. G. Ramos, S. A. Sousa, A. M. Grilo, J. R. Feliciano, and J. H. Leitao, J. Bacteriol. 193:15151526, 2011. doi:10.1128/JB.01374-11. S. A. Sousa, C. G. Ramos, L. M. Moreira, and J. H. Leitao, Microbiology 156:896908, 2010. doi:10.1099/mic.0.035139-0. C. G. Ramos, S. A. Sousa, A. M. Grilo, L. Eberl, and J. H. Leitao, Microb. Pathog. 48:168177, 2010. doi: 10.1016/j.micpath.2010.02.006. Therefore, we retract the paper. We deeply regret this situation and apologize for any inconvenience to the editors and readers of Journal of Bacteriology, Microbial Pathogenesis, and Microbiology.

Nillegoda NB et al. (2015) Nature "Crucial HSP70 co-chaperone complex unlocks metazoan protein disaggregation."

Berynskyy M, Morimoto RI, Bukau B, Stengel F, Kirstein J, Szlachcic A, Arnsburg K, Stank A, Scior A, Nillegoda NB, Gao X, Guilbride DL, Aebersold R, Wade RC, Mayer MP

[Nature, 2015]

Protein aggregates are the hallmark of stressed and ageing cells, and characterize several pathophysiological states. Healthy metazoan cells effectively eliminate intracellular protein aggregates, indicating that efficient disaggregation and/or degradation mechanisms exist. However, metazoans lack the key heat-shock protein disaggregase HSP100 of non-metazoan HSP70-dependent protein disaggregation systems, and the human HSP70 system alone, even with the crucial HSP110 nucleotide exchange factor, has poor disaggregation activity in vitro. This unresolved conundrum is central to protein quality control biology. Here we show that synergic cooperation between complexed J-protein co-chaperones of classes A and B unleashes highly efficient protein disaggregation activity in human and nematode HSP70 systems. Metazoan mixed-class J-protein complexes are transient, involve complementary charged regions conserved in the J-domains and carboxy-terminal domains of each J-protein class, and are flexible with respect to subunit composition. Complex formation allows J-proteins to initiate transient higher order chaperone structures involving HSP70 and interacting nucleotide exchange factors. A network of cooperative class A and B J-protein interactions therefore provides the metazoan HSP70 machinery with powerful, flexible, and finely regulatable disaggregase activity and a further level of regulation crucial for cellular protein quality control.

Miller DM et al. (1992) Worm Breeder's Gazette "unc-4 LacZ Expression in A-Type Motor Neurons"

Miller DM, Niemeyer CJ

[Worm Breeder's Gazette, 1992]

unc-4 LacZ expression in A-type motor neurons David M. Miller and Charles J. Niemeyer, Dept. of Cell Biology, Duke Univ. Medical Ctr, Durham, NC 27710

Sommer RJ et al. (1994) Worm Breeder's Gazette "Evolution of Vulva-Formation: Part II: Species With a Central Vulva"

Sommer RJ, Sternberg PW

[Worm Breeder's Gazette, 1994]

Evolution of vulva-formation: Part II: Species with a central vulva Ralf J. Sommer & Paul W. Sternberg, California Institute of Technology, Division of Biology 156-29, Pasadena, CA 91125

Jun-ichi Aikawa (2001) International C. elegans Meeting "Molecular characterization of heparan sulfate/heparin N-deacetylase/N-sulfotransferase in worms"

Jun-ichi Aikawa

[International C. elegans Meeting, 2001]

Heparan sulfate binds and activates a large variety of growth factors, enzymes and extracellular matrix proteins. These interactions largely depend on the specific arrangement of sulfated moieties and uronic acid epimers within the chains. These oligosaccharide sequences are generated in a step-wise manner, initiated by the formation of a linkage tetrasaccharide which is then extended by copolymerization of alternating a1,4GlcNAc and b1,4GlcA residues. As the chains polymerize, they undergo a series of sulfation and epimerization reactions. The first set of modifications involves the removal of acetyl units from subsets of GlcNAc residues, and the addition of sulfate groups to the resulting free amino groups. These reactions are catalyzed by a family of enzymes designated as GlcNAc N-deacetylase/N-sulfotransferases (NDST), since they simultaneously. Four members of the family have been identified in vertebrates, with single orthologs present in Drosophila and C. elegans. We have revealed tissue-specific expression pattern and unique enzymatic properties of these four isozymes1,2). In fly, loss of NDST (sulfateless) results in unsulfated chains and defective signaling by multiple growth factors and morphogens. I reconstituted cDNA for worm NDST from EST clones and 5' RACE products. Enzymatic activities will be discussed. 1) Aikawa, J. & Esko, J. D J. Biol. Chem. 274, 2690-2695 (1999) 2) Aikawa, J., Grobe, K., Tsujimoto, M. & Esko, J. D J. Biol. Chem. 276, 5876-5882 (2001)

Dreyfus DH et al. (1999) Mol Immunol "Comparative analysis of invertebrate Tc6 sequences that resemble the vertebrate V(D)J recombination signal sequences (RSS)."

Gelfand EW, Dreyfus DH

[Mol Immunol, 1999]

Invertebrate cells lack the p53 recombination checkpoint but contain mobile DNA sequences that transpose by a mechanism in part shared with excision of the V(D)J recombination signal sequences (RSS). In this work, inversion, deletion, and duplication of sequences associated with an invertebrate C. elegans Tc6 element is described. The structure of this C. elegans sequence and other dispersed Tc6 elements suggests that covalently closed 'hairpin' structures are not unique to excision of the V(D)J RSS by the RAG proteins, but rather can be generated by transposases at transposon termini leading to characteristic inversion and duplication events. Comparative analysis of recombination events at invertebrate sequences resembling the vertebrate V(D)J RSS may be useful in understanding V(D)J recombination-mediated recombination events in malignant vertebrate cells or genetic diseases such as ataxia telangectasia, in which the p53 recombination checkpoint is defective.