title: The C-terminal part of the CDC25 gene product has Ras-nucleotide exchange activity when present in a chimeric SDC25-CDC25 protein.
abstract: The CDC25 gene from S. cerevisiae encodes an activator of Ras proteins. The C-terminal part of a structurally-related protein encoded by the SDC25 gene is characterised by a Ras-guanine nucleotide exchange activity in vitro whereas the C-terminal part of CDC25 gives no detectable exchange activity. A chimera between the 3' regions of these two genes was constructed by homeologous recombination. This chimeric gene suppresses cdc25 mutations. When expressed in E. coli, the chimeric product is detectable by antibodies directed against the carboxy-terminal CDC25 peptide and has an exchange-factor activity on the Ras2 protein. Therefore, the carboxy-terminal parts of both the CDC25 and the SDC25 gene products are structurally and functionally similar. The CDC25 part of the chimeric protein contains an intrinsic guanine exchange factor which does not require an additional cofactor.
authors.affiliation: IGD, URA C.N.R.S. 1354, Université Paris-Sud, Orsay, France.
authors.forename: E
authors.initials: E
authors.lastname: Boy-Marcotte
authors.forename: A
authors.initials: A
authors.lastname: Buu
authors.forename: C
authors.initials: C
authors.lastname: Soustelle
authors.forename: P
authors.initials: P
authors.lastname: Poullet
authors.forename: A
authors.initials: A
authors.lastname: Parmeggiani
authors.forename: M
authors.initials: M
authors.lastname: Jacquet
mesh_terms: D001483:Base Sequence; D018797:Cell Cycle Proteins; D003001:Cloning, Molecular; D004247:DNA; D004926:Escherichia coli; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D020662:Guanine Nucleotide Exchange Factors; D008969:Molecular Sequence Data; D011506:Proteins / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D015183:Restriction Mapping; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D012689:Sequence Homology, Nucleic Acid; D013489:Suppression, Genetic; D020668:rap GTP-Binding Proteins; D020663:ras Guanine Nucleotide Exchange Factors; D018631:ras Proteins; D020666:ras-GRF1
chemical_list: C542351:CDC25 protein, S cerevisiae; D018797:Cell Cycle Proteins; D005656:Fungal Proteins; D020662:Guanine Nucleotide Exchange Factors; D011506:Proteins; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D020663:ras Guanine Nucleotide Exchange Factors; D020666:ras-GRF1; D004247:DNA; D019204:GTP-Binding Proteins; C489015:RAS2 protein, S cerevisiae; D020668:rap GTP-Binding Proteins; D018631:ras Proteins