In the yeast Saccharomyces cerevisiae, the Cdc25/Ras/cAMP/protein kinase A (PKA) pathway plays a major role in the control of metabolism, stress resistance and proliferation, in relation to the available nutrients and conditions. The budding yeast RasGEF Cdc25 was the first RasGEF to be identified in any organism, but very little is known about its activity regulation. Recently, it was suggested that the dispensable N-terminal domain of Cdc25 could negatively control the catalytic activity of the protein. In order to investigate the role of this domain, strains were constructed that produced two different versions of the C-terminal domain of Cdc25 (aa 907–1589 and 1147–1589). The carbon-source-dependent cell size control mechanism present in the wild type was found in the first of these mutants, but was lost in the second mutant, for which the cell size, determined as protein content, was the same during exponential growth in both ethanol- and glucose-containing media. A biparametric analysis demonstrated that this effect was essentially due to the inability of the mutant producing the shorter sequence to modify its protein content at budding. A similar phenotype was observed in strains that lacked CDC25, but which possessed a mammalian GEF catalytic domain. Taken together, these results suggest that Cdc25 is involved in the regulation of cell size in the presence of different carbon sources. Moreover, production of the aa 876–1100 fragment increased heat-stress resistance in the wild-type strain, and rescued heat-shock sensitivity in the ira1 delta background. Further work will aim to clarify the role of this region in Cdc25 activity and Ras/cAMP pathway regulation.

Belotti, F., Tisi, R., & Martegani, E. (2006). The N-terminal region of the Saccharomyces cerevisiae RasGEF Cdc25 is required for nutrient-dependent cell-size regulation. MICROBIOLOGY, 152, 1231-1242 [10.1099/mic.0.28683-0].

The N-terminal region of the Saccharomyces cerevisiae RasGEF Cdc25 is required for nutrient-dependent cell-size regulation.

BELOTTI, FIORELLA;TISI, RENATA ANITA;MARTEGANI, ENZO
2006

Abstract

In the yeast Saccharomyces cerevisiae, the Cdc25/Ras/cAMP/protein kinase A (PKA) pathway plays a major role in the control of metabolism, stress resistance and proliferation, in relation to the available nutrients and conditions. The budding yeast RasGEF Cdc25 was the first RasGEF to be identified in any organism, but very little is known about its activity regulation. Recently, it was suggested that the dispensable N-terminal domain of Cdc25 could negatively control the catalytic activity of the protein. In order to investigate the role of this domain, strains were constructed that produced two different versions of the C-terminal domain of Cdc25 (aa 907–1589 and 1147–1589). The carbon-source-dependent cell size control mechanism present in the wild type was found in the first of these mutants, but was lost in the second mutant, for which the cell size, determined as protein content, was the same during exponential growth in both ethanol- and glucose-containing media. A biparametric analysis demonstrated that this effect was essentially due to the inability of the mutant producing the shorter sequence to modify its protein content at budding. A similar phenotype was observed in strains that lacked CDC25, but which possessed a mammalian GEF catalytic domain. Taken together, these results suggest that Cdc25 is involved in the regulation of cell size in the presence of different carbon sources. Moreover, production of the aa 876–1100 fragment increased heat-stress resistance in the wild-type strain, and rescued heat-shock sensitivity in the ira1 delta background. Further work will aim to clarify the role of this region in Cdc25 activity and Ras/cAMP pathway regulation.
Articolo in rivista - Articolo scientifico
Cdc25 mutants; cell size; nutrient sensing
English
Belotti, F., Tisi, R., & Martegani, E. (2006). The N-terminal region of the Saccharomyces cerevisiae RasGEF Cdc25 is required for nutrient-dependent cell-size regulation. MICROBIOLOGY, 152, 1231-1242 [10.1099/mic.0.28683-0].
Belotti, F; Tisi, R; Martegani, E
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/10281/5191
Citazioni
  • Scopus 12
  • ???jsp.display-item.citation.isi??? 12
Social impact