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The Caenorhabditis elegans peroxidasins, PXN-1 and PXN-2, are extracellular peroxidases; pxn-2 is involved in muscleepidermal attachment during embryonic morphogenesis and in specific axon guidance. Here we investigate potential roles of the other homologue of peroxidasin, pxn-1, in C. elegans. A pxn-1 deletion mutant showed high lethality under heat-stress conditions. Using a transcriptional GFP reporter, pxn-1 expression was observed in various tissues including neurons, muscles, and hypodermis. A translational fusion showed that PXN-1::GFP was secreted and localized in extracellular matrix, particularly along body wall muscles and pharyngeal muscles. Various neuronal developmental defects were observed in pxn-1 mutants and in pxn-1 over-expressing animals, including handedness, branching, breakage, tangling, and defasciculation. These results suggest that pxn-1, like other peroxidasins, plays an important role throughout development. [ABSTRACT FROM AUTHOR]

NOG1 is a nucleolar GTPase that is critical for 60S ribosome biogenesis. Recently, NOG1 was identified as one of the downstream regulators of target of rapamycin (TOR) in yeast. It is reported that TOR is involved in regulating lifespan and fat storage in Caenorhabditis elegans. Here, we show that the nog1 ortholog (T07A9.9: nog-1) in C. elegans regulates growth, development, lifespan, and fat metabolism. A green fluorescence protein (GFP) promoter assay revealed ubiquitous expression of C. elegans nog-1 from the early embryonic to the adult stage. Furthermore, the GFP-tagged NOG-1 protein is localized to the nucleus, whereas the aberrant NOG-1 protein is concentrated in the nucleolus. Functional studies of NOG-1 in C. elegans further revealed that nog-1 knockdown resulted in smaller broodsize, slower growth, increased life span, and more fat storage. Moreover, nog-1 over-expression resulted in decreased life span. Taken together, our data suggest that nog-1 in C. elegans may be an important player in regulating life span and fat storage via the insulin/IGF pathway. [ABSTRACT FROM AUTHOR]

Thioredoxin reductase (TrxR) is a member of the pyridine nucleotide-disulfide reductase family, which mainly functions in the thioredoxin system. TrxR is found in all living organisms and exists in two major ubiquitous isoenzymes in higher eukaryotic cells; One is cytosolic and the other mitochondrial. Mitochondrial TrxR functions to protect mitochondria from oxidative stress, where reactive oxidative species are mainly generated, while cytosolic TrxR plays a role to maintain optimal oxido-reductive status in cytosol. In this study, we report differential physiological functions of these two TrxRs in C. elegans. trxr-1, the cytosolic TrxR, is highly expressed in pharynx, vulva and intestine, whereas trxr-2, the mitochondrial TrxR, is mainly expressed in pharyngeal and body wall muscles. Deficiency of the non-selenoprotein trxr-2 caused defects in longevity and delayed development under stress conditions, while deletion mutation of the selenoprotein trxr-1 resulted in interference in acidification of lysosomal compartment in intestine. Interestingly, the acidification defect of trxr-1(jh143) deletion mutant was rescued, not only by selenocystein-containing wild type TRXR-1, but also cysteine-substituted mutant TRXR-1. Both trxr-1 and trxr-2 were up-regulated when worms were challenged by environmental stress such as heat shock. These results suggest that trxr-1 and trxr-2 function differently at organismal level presumably by their differential sub-cellular localization in C. elegans. [ABSTRACT FROM AUTHOR]

Calcineurin is a calcium/calmodulin-dependent serine/threonine protein phosphatase. It is a heterodimeric protein consisting of a catalytic subunit calcineurin A, and a regulatory calcium-binding subunit, calcineurin B. The primary sequence of both subunits and heterodimeric structure is highly conserved from yeast to mammals. Calcineurin has long been implicated in various signaling pathways. Calcineurin genes (cna- 1/tax-6 and cnb-1) have been identified in the nematode Caenorhabditis elegans, which share high homology with their Drosophila and mammalian counterparts. C. elegans calcineurin binds calcium and functions as a heterodimeric protein phosphatase establishing its biochemical conservation. Calcineurin expresses in diverse tissues implicating its important role in various physiological processes. This review will focus in brief on the expression pattern and regulation of calcineurin including its effect on growth and development, locomotion, egg-laying, and sensory responses. [ABSTRACT FROM AUTHOR]