Different domains of the essential GTPase Cdc42p required for growth and development of Saccharomyces cerevisiae.
In budding yeast, the Rho-type GTPase Cdc42p is essential for cell division and regulates pseudohyphal development and invasive growth. Here, we isolated novel Cdc42p mutant proteins with single-amino-acid substitutions that are sufficient to uncouple functions of Cdc42p essential for cell division from regulatory functions required for pseudohyphal development and invasive growth. In haploid cells, Cdc42p is able to regulate invasive growth dependent on and independent of FLO11 gene expression. In diploid cells, Cdc42p regulates pseudohyphal development by controlling pseudohyphal cell (PH cell) morphogenesis and invasive growth. Several of the Cdc42p mutants isolated here block PH cell morphogenesis in response to nitrogen starvation without affecting morphology or polarity of yeast form cells in nutrient-rich conditions, indicating that these proteins are impaired for certain signaling functions. Interaction studies between development-specific Cdc42p mutants and known effector proteins indicate that in addition to the p21-activated (PAK)-like protein kinase Ste20p, the Cdc42p/Rac-interactive-binding domain containing Gic1p and Gic2p proteins and the PAK-like protein kinase Skm1p might be further effectors of Cdc42p that regulate pseudohyphal and invasive growth.
Mösch
H U
HU
Institute for Microbiology and Genetics, Georg-August University, D-37077 Göttingen, Germany. hmoesch@gwdg.de
Köhler
T
T
Braus
G H
GH
D000199:Actins / Q000378:metabolism; D000483:Alleles; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution / Q000235:genetics; D002455:Cell Division; D016764:Cell Polarity; D002686:Chitin / Q000378:metabolism; D004843:Epistasis, Genetic; D020043:Genes, Essential / Q000235:genetics*; D005800:Genes, Fungal / Q000235:genetics; D006238:Haploidy; D047908:Intracellular Signaling Peptides and Proteins; D020930:MAP Kinase Kinase Kinases; D008562:Membrane Glycoproteins; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D008856:Microscopy, Fluorescence; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009024:Morphogenesis; D009154:Mutation / Q000235:genetics; D009584:Nitrogen / Q000378:metabolism; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D016415:Sequence Alignment; D020798:Two-Hybrid System Techniques; D020846:cdc42 GTP-Binding Protein, Saccharomyces cerevisiae / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
D000199:Actins; C110690:FLO11 protein, S cerevisiae; D047908:Intracellular Signaling Peptides and Proteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D029701:Saccharomyces cerevisiae Proteins; D002686:Chitin; D017346:Protein Serine-Threonine Kinases; D020930:MAP Kinase Kinase Kinases; C078754:STE20 protein, S cerevisiae; D020846:cdc42 GTP-Binding Protein, Saccharomyces cerevisiae; D009584:Nitrogen