title: New roles for CDC25 in growth control, galactose regulation and cellular differentiation in Saccharomyces cerevisiae.
abstract: Living organisms display large differences in stress resistance throughout their life cycles. To study the coordinated regulation of development and stress responses in exponentially growing yeast, mutants that displayed elevated heat-shock resistance at this stage were screened for. Here, two new mutant alleles of CDC25 in Saccharomyces cerevisiae, cdc25-21 and cdc25-22, are described. During exponential growth in glucose at 25 degrees C, these mutants are resistant to heat, oxidative, osmotic and ionic shock, accumulate stress-protein transcripts, show slow growth rates, thick cell walls and glycogen hyperaccumulation and lack cAMP signalling in response to glucose. Genetic and cellular analyses revealed that the stationary-phase phenotypes of cdc25-21 and cdc25-22 mutants are not due to entrance to a G(0) state during exponential growth, but are the result of a prolonged G(1) phase. It was found that, in the W303 background, CDC25 is dispensable for growth in glucose media. However, CDC25 is essential for growth in galactose, in non-fermentable carbon sources and under continuous incubation at 38 degrees C. In conclusion, the function of the catalytic, C-terminal domain of Cdc25p is not only important for fermentative growth, but also for growth in non-fermentable carbon sources and to trigger galactose derepression.
authors.affiliation: Department of Plant Molecular Biology, Instituto de Biotecnología de la UNAM, 62250 Cuernavaca, Mor., Mexico.
authors.forename: Jorge Luis
authors.initials: JL
authors.lastname: Folch-Mallol
authors.affiliation: Department of Plant Molecular Biology, Instituto de Biotecnología de la UNAM, 62250 Cuernavaca, Mor., Mexico.
authors.forename: Luz María
authors.initials: LM
authors.lastname: Martínez
authors.affiliation: Department of Plant Molecular Biology, Instituto de Biotecnología de la UNAM, 62250 Cuernavaca, Mor., Mexico.
authors.forename: Sergio J
authors.initials: SJ
authors.lastname: Casas
authors.affiliation: Department of Plant Molecular Biology, Instituto de Biotecnología de la UNAM, 62250 Cuernavaca, Mor., Mexico.
authors.forename: Runying
authors.initials: R
authors.lastname: Yang
authors.affiliation: Department of Plant Molecular Biology, Instituto de Biotecnología de la UNAM, 62250 Cuernavaca, Mor., Mexico.
authors.forename: Claudia
authors.initials: C
authors.lastname: Martínez-Anaya
authors.affiliation: Department of Plant Molecular Biology, Instituto de Biotecnología de la UNAM, 62250 Cuernavaca, Mor., Mexico.
authors.forename: Lorena
authors.initials: L
authors.lastname: López
authors.affiliation: Department of Plant Molecular Biology, Instituto de Biotecnología de la UNAM, 62250 Cuernavaca, Mor., Mexico.
authors.forename: Alejandra
authors.initials: A
authors.lastname: Hernández
authors.affiliation: Department of Plant Molecular Biology, Instituto de Biotecnología de la UNAM, 62250 Cuernavaca, Mor., Mexico.
authors.forename: Jorge
authors.initials: J
authors.lastname: Nieto-Sotelo
mesh_terms: D000222:Adaptation, Physiological; D002453:Cell Cycle; D018797:Cell Cycle Proteins / Q000235:genetics* / Q000502:physiology*; D002473:Cell Wall / Q000648:ultrastructure; D000242:Cyclic AMP / Q000032:analysis / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics* / Q000502:physiology*; D005690:Galactose / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D020043:Genes, Essential; D005800:Genes, Fungal; D005947:Glucose / Q000502:physiology; D006003:Glycogen / Q000378:metabolism; D006360:Heat-Shock Proteins / Q000235:genetics; D006358:Hot Temperature; D009154:Mutation; D009997:Osmotic Pressure; D018384:Oxidative Stress; D012329:RNA, Bacterial / Q000032:analysis / Q000302:isolation & purification; D012333:RNA, Messenger / Q000032:analysis / Q000302:isolation & purification; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics* / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000502:physiology; D017384:Sequence Deletion; D020666:ras-GRF1 / Q000235:genetics* / Q000502:physiology*
chemical_list: D018797:Cell Cycle Proteins; D005656:Fungal Proteins; D006360:Heat-Shock Proteins; D012329:RNA, Bacterial; D012333:RNA, Messenger; D029701:Saccharomyces cerevisiae Proteins; D020666:ras-GRF1; D006003:Glycogen; D000242:Cyclic AMP; D005947:Glucose; D005690:Galactose