title: Cloning and characterization of the C. elegans gas1 homolog: phas-1.
abstract: Among the set of genes expressed during the quiescent G0 phase of the cell cycle (gas genes), gas1 encodes for a GPI anchor protein associated to the plasma membrane, which is able to induce growth arrest when overexpressed in proliferating fibroblasts. In this report we describe the isolation and characterization of a gas1 Caenorhabditis elegans homolog, phas-1, that seems to be transcribed as an operon together with a gene encoding for a protein similar to human acid ceramidases. Phas-1 structure is very similar to its mammalian homolog conserving almost all cysteine residues and it is expressed in the pharynx from its early formation, in the two-fold embryo, until the adult stage. Surprisingly, while phas-1 is expressed in all developmental stages, with the exception of the dauer larva, the ceramidase-like encoding gene, co-expressed in the same operon together with phas-1, is absent in embryos and is very abundantly expressed in the dauer larva. Overexpression of phas-1 in growing NIH3T3 fibroblasts is able to inhibit the S-phase entry in a similar manner as its murine homolog. On the other hand, when phas-1 is overexpressed or ablated in C. elegans, no specific phenotype due to its transcription alteration can be observed, despite its localized expression suggesting a role in pharynx function or development.
authors.affiliation: Laboratorio Nazionale C.I.B., Area Science Park, Padriciano, 99, 34012, Trieste, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Agostoni
authors.forename: Stefania
authors.initials: S
authors.lastname: Gobessi
authors.forename: Enrica
authors.initials: E
authors.lastname: Petrini
authors.forename: Martin
authors.initials: M
authors.lastname: Monte
authors.forename: Claudio
authors.initials: C
authors.lastname: Schneider
mesh_terms: D016475:3T3 Cells; D000581:Amidohydrolases / Q000235:genetics; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017173:Caenorhabditis elegans / Q000196:embryology / Q000235:genetics* / Q000254:growth & development; D029742:Caenorhabditis elegans Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D015815:Cell Adhesion Molecules / Q000235:genetics*; D018797:Cell Cycle Proteins / Q000235:genetics; D055572:Ceramidases; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000096:biosynthesis / Q000737:chemistry; D004625:Embryo, Nonmammalian / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D017238:Genes, Helminth; D017261:Glycosylphosphatidylinositols / Q000737:chemistry / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics; D051379:Mice; D008969:Molecular Sequence Data; D009876:Operon; D010614:Pharynx / Q000378:metabolism; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid; D014162:Transfection
chemical_list: D029742:Caenorhabditis elegans Proteins; D015815:Cell Adhesion Molecules; D018797:Cell Cycle Proteins; D018076:DNA, Complementary; D017261:Glycosylphosphatidylinositols; D008565:Membrane Proteins; C456622:phg-1 protein, C elegans; D000581:Amidohydrolases; D055572:Ceramidases