title: The PTEN tumor suppressor homolog in Caenorhabditis elegans regulates longevity and dauer formation in an insulin receptor-like signaling pathway.
abstract: Inactivation of the tumor suppressor PTEN gene is found in a variety of human cancers and in cancer predisposition syndromes. Recently, PTEN protein has been shown to possess phosphatase activity on phosphatidylinositol 3,4,5-trisphosphate, a product of phosphatidylinositol 3-kinase. We have identified a homolog of PTEN in Caenorhabditis elegans and have found that it corresponds to the daf-18 gene, which had been defined by a single, phenotypically weak allele, daf-18(e1375). By analyzing an allele, daf-18(nr2037), which bears a deletion of the catalytic portion of CePTEN/DAF-18, we have shown that mutation in daf-18 can completely suppress the dauer-constitutive phenotype caused by inactivation of daf-2 or age-1, which encode an insulin receptor-like molecule and the catalytic subunit of phosphatidylinositol 3-kinase, respectively. In addition, daf-18(nr2037) dramatically shortens lifespan, both in a wild-type background and in a daf-2 mutant background that normally prolongs lifespan. The lifespan in a daf-18(nr2037) mutant can be restored to essentially that of wild type when combined with a daf-2 mutation. Our studies provide genetic evidence that, in C. elegans, the PTEN homolog DAF-18 functions as a negative regulator of the DAF-2 and AGE-1 signaling pathway, consistent with the notion that DAF-18 acts a phosphatidylinositol 3,4,5-trisphosphate phosphatase in vivo. Furthermore, our studies have uncovered a longevity-promoting activity of the PTEN homolog in C. elegans.
authors.affiliation: Department of Genetics, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA.
authors.forename: V T
authors.initials: VT
authors.lastname: Mihaylova
authors.forename: C Z
authors.initials: CZ
authors.lastname: Borland
authors.forename: L
authors.initials: L
authors.lastname: Manjarrez
authors.forename: M J
authors.initials: MJ
authors.lastname: Stern
authors.forename: H
authors.initials: H
authors.lastname: Sun
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017173:Caenorhabditis elegans / Q000502:physiology*; D029742:Caenorhabditis elegans Proteins; D005786:Gene Expression Regulation / Q000502:physiology; D016147:Genes, Tumor Suppressor; D015801:Helminth Proteins / Q000502:physiology*; D006801:Humans; D008969:Molecular Sequence Data; D051059:PTEN Phosphohydrolase; D019869:Phosphatidylinositol 3-Kinases; D010744:Phosphoric Monoester Hydrolases / Q000235:genetics*; D011972:Receptor, Insulin / Q000502:physiology*; D016415:Sequence Alignment; D015398:Signal Transduction / Q000235:genetics; D025521:Tumor Suppressor Proteins
chemical_list: D029742:Caenorhabditis elegans Proteins; C116661:DAF-18 protein, C elegans; D015801:Helminth Proteins; D025521:Tumor Suppressor Proteins; D019869:Phosphatidylinositol 3-Kinases; C100662:AGE-1 protein, C elegans; C107483:DAF-2 protein, C elegans; D011972:Receptor, Insulin; D010744:Phosphoric Monoester Hydrolases; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human