Ras2 signals via the Cdc42/Ste20/mitogen-activated protein kinase module to induce filamentous growth in Saccharomyces cerevisiae.
RAS2val19, a dominant activated form of Saccharomyces cerevisiae Ras2, stimulates both filamentous growth and expression of a transcriptional reporter FG(TyA)::lacZ but does not induce the mating pathway reporter FUS1::lacZ. This induction depends upon elements of the conserved mitogen-activated protein kinase (MAPK) pathway that is required for both filamentous growth and mating, two distinct morphogenetic events. Full induction requires Ste20 (homolog of mammalian p65PAK protein kinases), Ste11 [an MEK kinase (MEKK) or MAPK kinase (MEK) kinase], Ste7 (MEK or MAPK kinase), and the transcription factor Ste12. Moreover, the Rho family protein Cdc42, a conserved morphogenetic G protein, is also a potent regulator of filamentous growth and FG(TyA)::lacZ expression in S. cerevisiae. Stimulation of both filamentous growth and FG(TyA)::lacZ by Cdc42 depends upon Ste20. In addition, dominant negative CDC42Ala118 blocks RAS2val19 activation, placing Cdc42 downstream of Ras2. Our results suggest that filamentous growth in budding yeast is regulated by an evolutionarily conserved signaling pathway that controls cell morphology.
Mösch
H U
HU
Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, 02142, USA.
Roberts
R L
RL
Fink
G R
GR
D000818:Animals; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000378:metabolism*; D005656:Fungal Proteins / Q000378:metabolism*; D020558:GTP Phosphohydrolases / Q000378:metabolism; D019204:GTP-Binding Proteins / Q000378:metabolism*; D005838:Genotype; D047908:Intracellular Signaling Peptides and Proteins; D020930:MAP Kinase Kinase Kinases; D008322:Mammals; D010957:Plasmids; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011994:Recombinant Proteins / Q000096:biosynthesis; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D015398:Signal Transduction; D014157:Transcription Factors / Q000378:metabolism; D001616:beta-Galactosidase / Q000096:biosynthesis; D020846:cdc42 GTP-Binding Protein, Saccharomyces cerevisiae; D018631:ras Proteins / Q000378:metabolism*
D018797:Cell Cycle Proteins; D005656:Fungal Proteins; D047908:Intracellular Signaling Peptides and Proteins; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D017346:Protein Serine-Threonine Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D020930:MAP Kinase Kinase Kinases; C078754:STE20 protein, S cerevisiae; D001616:beta-Galactosidase; D020558:GTP Phosphohydrolases; D019204:GTP-Binding Proteins; C489015:RAS2 protein, S cerevisiae; D020846:cdc42 GTP-Binding Protein, Saccharomyces cerevisiae; D018631:ras Proteins