title: A new pathway for heavy metal detoxification in animals. Phytochelatin synthase is required for cadmium tolerance in Caenorhabditis elegans.
abstract: Increasing emissions of heavy metals such as cadmium, mercury, and arsenic into the environment pose an acute problem for all organisms. Considerations of the biochemical basis of heavy metal detoxification in animals have focused exclusively on two classes of peptides, the thiol tripeptide, glutathione (GSH, gamma-Glu-Cys-Gly), and a diverse family of cysteine-rich low molecular weight proteins, the metallothioneins. Plants and some fungi, however, not only deploy GSH and metallothioneins for metal detoxification but also synthesize another class of heavy metal binding peptides termed phytochelatins (PCs) from GSH. Here we show that PC-mediated heavy metal detoxification is not restricted to plants and some fungi but extends to animals by demonstrating that the ce-pcs-1 gene of the nematode worm Caenorhabditis elegans encodes a functional PC synthase whose activity is critical for heavy metal tolerance in the intact organism.
authors: Department of Biology, Plant Science Institute, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6018, USA.
authors: O K
authors: OK
authors: Vatamaniuk
authors: E A
authors: EA
authors: Bucher
authors: J T
authors: JT
authors: Ward
authors: P A
authors: PA
authors: Rea
mesh_terms: D019881:Aminoacyltransferases / Q000235:genetics* / Q000378:metabolism*; D000818:Animals; D019256:Cadmium Chloride / Q000493:pharmacokinetics* / Q000633:toxicity; D017173:Caenorhabditis elegans / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D017353:Gene Deletion; D005978:Glutathione / Q000378:metabolism; D008658:Inactivation, Metabolic; D008667:Metalloproteins / Q000378:metabolism; D008668:Metallothionein / Q000378:metabolism; D019216:Metals, Heavy / Q000493:pharmacokinetics*; D054811:Phytochelatins; D010940:Plant Proteins / Q000378:metabolism; D012330:RNA, Double-Stranded / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000201:enzymology
chemical_list: D008667:Metalloproteins; D019216:Metals, Heavy; D010940:Plant Proteins; D012330:RNA, Double-Stranded; D008668:Metallothionein; D054811:Phytochelatins; D019881:Aminoacyltransferases; C093784:glutathione gamma-glutamylcysteinyltransferase; D005978:Glutathione; D019256:Cadmium Chloride