A cytosolic catalase is needed to extend adult lifespan in C. elegans daf-C and clk-1 mutants.
The dauer larva is an alternative larval stage in Caenorhabditis elegans which allows animals to survive through periods of low food availability. Well-fed worms live for about three weeks, but dauer larvae can live for at least two months without affecting post-dauer lifespan. Mutations in daf-2 and age-1, which produce a dauer constitutive (Daf-C) phenotype, and in clk-1, which are believed to slow metabolism, markedly increase adult lifespan. Here we show that a ctl-1 mutation reduces adult lifespan in otherwise wild-type animals and eliminates the daf-c and clk-1-mediated extension of adult lifespan. ctl-1 encodes an unusual cytosolic catalase; a second gene, ctl-2, encodes a peroxisomal catalase. ctl-1 messenger RNA is increased in dauer larvae and adults with the daf-c mutations. We suggest that the ctl-1 catalase is needed during periods of starvation, as in the dauer larva, and that its misexpression in daf-c and clk-1 adults extends lifespan. Cytosolic catalase may have evolved to protect nematodes from oxidative damage produced during prolonged dormancy before reproductive maturity, or it may represent a general mechanism for permitting organisms to cope with the metabolic changes that accompany starvation.
Taub
J
J
Department of Biological Sciences, Columbia University, New York, New York 10027, USA.
Lau
J F
JF
Ma
C
C
Hahn
J H
JH
Hoque
R
R
Rothblatt
J
J
Chalfie
M
M
D000818:Animals; D017173:Caenorhabditis elegans / Q000201:enzymology / Q000235:genetics / Q000502:physiology*; D029742:Caenorhabditis elegans Proteins; D002374:Catalase / Q000235:genetics / Q000502:physiology*; D003600:Cytosol / Q000201:enzymology; D015870:Gene Expression; D017238:Genes, Helminth; D015801:Helminth Proteins / Q000235:genetics / Q000502:physiology*; D008136:Longevity / Q000235:genetics / Q000502:physiology*; D008969:Molecular Sequence Data; D009154:Mutation; D018384:Oxidative Stress; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism
C104339:CLK-1 protein, C elegans; D029742:Caenorhabditis elegans Proteins; D015801:Helminth Proteins; D011993:Recombinant Fusion Proteins; D002374:Catalase