scholarly journals Inhibition of Cdc42-dependent signalling in Saccharomyces cerevisiae by phosphatase-dead SigD/SopB from Salmonella typhimurium

Microbiology ◽  
2006 ◽  
Vol 152 (11) ◽  
pp. 3437-3452 ◽  
Author(s):  
Isabel Rodríguez-Escudero ◽  
Rafael Rotger ◽  
Víctor J. Cid ◽  
María Molina
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Growth Inhibition ◽  
Salmonella Typhimurium ◽  
Map Kinase ◽  
Protein A ◽  
Small Gtpases ◽  
Second Growth ◽  
A Cell ◽  
Arrest Growth

Heterologous expression of bacterial virulence factors in Saccharomyces cerevisiae is a feasible approach to study their molecular function. The authors have previously reported that the Salmonella typhimurium SigD protein, a phosphatidylinositol phosphatase involved in invasion of the host cell, inhibits yeast growth, presumably by depleting an essential pool of phosphatidylinositol 4,5-bisphosphate, and also that a catalytically inactive version, SigDR468A, was able to arrest growth by a different mechanism that involved disruption of the actin cytoskeleton. This paper describes marked differences between the phenotypes elicited by expression of SigD and SigDR468A in yeast. First, expression of SigDR468A caused accumulation of large unbudded cells and loss of septin organization, while SigD expression caused none of these effects. Second, growth inhibition by SigDR468A was mediated by a cell cycle arrest in G2 dependent on the Swe1 morphogenetic checkpoint, but SigD-induced growth inhibition was cell cycle independent. And third, SigD caused strong activation of the yeast MAP kinase Slt2, whereas SigDR468A rather inactivated another MAP kinase, Kss1. In a screen for suppressors of SigDR468A-induced growth arrest by overexpression of a yeast cDNA library, the Cdc42 GTPase was isolated. Furthermore, SigDR468A was co-purified with Cdc42 from yeast lysates. It is concluded that the Salmonella SigD protein deprived of its phosphatase activity is able to disrupt yeast morphogenesis by interfering with Cdc42 function, opening the possibility that the SigD N-terminal region might directly modulate small GTPases from the host during infection.

scholarly journals Farnesol-induced growth inhibition in Saccharomyces cerevisiae by a cell cycle mechanism

Microbiology ◽  
1999 ◽  
Vol 145 (2) ◽  
pp. 293-299 ◽  
Author(s):  
Kiyotaka Machida ◽  
Toshio Tanaka ◽  
Yoshihisa Yano ◽  
Shuzo Otani ◽  
Makoto Taniguchi
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Growth Inhibition ◽  
A Cell

scholarly journals Chs1p and Chs3p, two proteins involved in chitin synthesis, populate a compartment of the Saccharomyces cerevisiae endocytic pathway.

1996 ◽  
Vol 7 (12) ◽  
pp. 1909-1919 ◽  
Author(s):  
M Ziman ◽  
J S Chuang ◽  
R W Schekman
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Endocytic Pathway ◽  
Chitin Synthase ◽  
Cell Fractionation ◽  
Cell Wall Polysaccharide ◽  
Chitin Synthesis ◽  
A Cell ◽  
Steady State Levels ◽  
Membrane Bound

In Saccharomyces cerevisiae, the synthesis of chitin, a cell-wall polysaccharide, is temporally and spatially regulated with respect to the cell cycle and morphogenesis. Using immunological reagents, we found that steady-state levels of Chs1p and Chs3p, two chitin synthase enzymes, did not fluctuate during the cell cycle, indicating that they are not simply regulated by synthesis and degradation. Previous cell fractionation studies demonstrated that chitin synthase I activity (CSI) exists in a plasma membrane form and in intracellular membrane-bound particles called chitosomes. Chitosomes were proposed to act as a reservoir for regulated transport of chitin synthase enzymes to the division septum. We found that Chs1p and Chs3p resided partly in chitosomes and that this distribution was not cell cycle regulated. Pulse-chase cell fractionation experiments showed that chitosome production was blocked in an endocytosis mutant (end4-1), indicating that endocytosis is required for the formation or maintenance of chitosomes. Additionally, Ste2p, internalized by ligand-induced endocytosis, cofractionated with chitosomes, suggesting that these membrane proteins populate the same endosomal compartment. However, in contrast to Ste2p, Chs1p and Chs3p were not rapidly degraded, thus raising the possibility that the temporal and spatial regulation of chitin synthesis is mediated by the mobilization of an endosomal pool of chitin synthase enzymes.

scholarly journals Alteration/Deficiency in Activation 3 (ADA3) Protein, a Cell Cycle Regulator, Associates with the Centromere through CENP-B and Regulates Chromosome Segregation

2015 ◽  
Vol 290 (47) ◽  
pp. 28299-28310 ◽  
Author(s):  
Shakur Mohibi ◽  
Shashank Srivastava ◽  
Jun Wang-France ◽  
Sameer Mirza ◽  
Xiangshan Zhao ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Chromosome Segregation ◽  
Protein A ◽  
Cell Cycle Regulator ◽  
A Cell

scholarly journals Role of Cdc42-Cla4 Interaction in the Pheromone Response of Saccharomyces cerevisiae

2006 ◽  
Vol 6 (2) ◽  
pp. 317-327 ◽  
Author(s):  
Melanie Heinrich ◽  
Tim Köhler ◽  
Hans-Ulrich Mösch
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Map Kinase ◽  
Cell Cycle Arrest ◽  
Map Kinases ◽  
Negative Regulator ◽  
Cycle Arrest ◽  
Mitogen Activated Protein ◽  
Novel Alleles

ABSTRACT In Saccharomyces cerevisiae, the highly conserved Rho-type GTPase Cdc42 is essential for cell division and controls cellular development during mating and invasive growth. The role of Cdc42 in mating has been controversial, but a number of previous studies suggest that the GTPase controls the mitogen-activated protein (MAP) kinase cascade by activating the p21-activated protein kinase (PAK) Ste20. To further explore the role of Cdc42 in pheromone-stimulated signaling, we isolated novel alleles of CDC42 that confer resistance to pheromone. We find that in CDC42(V36A) and CDC42(V36A, I182T) mutant strains, the inability to undergo pheromone-induced cell cycle arrest correlates with reduced phosphorylation of the mating MAP kinases Fus3 and Kss1 and with a decrease in mating efficiency. Furthermore, Cdc42(V36A) and Cdc42(V36A, I182T) proteins show reduced interaction with the PAK Cla4 but not with Ste20. We also show that deletion of CLA4 in a CDC42(V36A, I182T) mutant strain suppresses pheromone resistance and that overexpression of CLA4 interferes with pheromone-induced cell cycle arrest and MAP kinase phosphorylation in CDC42 wild-type strains. Our data indicate that Cla4 has the potential to act as a negative regulator of the mating pathway and that this function of the PAK might be under control of Cdc42. In conclusion, our study suggests that control of pheromone signaling by Cdc42 not only depends on Ste20 but also involves interaction of the GTPase with Cla4.

scholarly journals Cell cycle–dependent phosphorylation of Sec4p controls membrane deposition during cytokinesis

2016 ◽  
Vol 214 (6) ◽  
pp. 691-703 ◽  
Author(s):  
Dante Lepore ◽  
Olya Spassibojko ◽  
Gabrielle Pinto ◽  
Ruth N. Collins
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Membrane Trafficking ◽  
Intracellular Trafficking ◽  
Rab Gtpase ◽  
Rab Gtpases ◽  
Positive Regulator ◽  
Physiological Relevance ◽  
A Cell ◽  
Cycle Dependent

Intracellular trafficking is an essential and conserved eukaryotic process. Rab GTPases are a family of proteins that regulate and provide specificity for discrete membrane trafficking steps by harnessing a nucleotide-bound cycle. Global proteomic screens have revealed many Rab GTPases as phosphoproteins, but the effects of this modification are not well understood. Using the Saccharomyces cerevisiae Rab GTPase Sec4p as a model, we have found that phosphorylation negatively regulates Sec4p function by disrupting the interaction with the exocyst complex via Sec15p. We demonstrate that phosphorylation of Sec4p is a cell cycle–dependent process associated with cytokinesis. Through a genomic kinase screen, we have also identified the polo-like kinase Cdc5p as a positive regulator of Sec4p phosphorylation. Sec4p spatially and temporally localizes with Cdc5p exclusively when Sec4p phosphorylation levels peak during the cell cycle, indicating Sec4p is a direct Cdc5p substrate. Our data suggest the physiological relevance of Sec4p phosphorylation is to facilitate the coordination of membrane-trafficking events during cytokinesis.

The plant homologue of MAP kinase is expressed in a cell cycle-dependent and organ-specific manner

1993 ◽  
Vol 3 (4) ◽  
pp. 611-617 ◽  
Author(s):  
Claudia Jonak ◽  
Aniko Páy ◽  
Laszlo Börge ◽  
Heribert Hirt ◽  
Erwin Heberle-Bors
Keyword(s):  
Cell Cycle ◽  
Map Kinase ◽  
Specific Manner ◽  
Organ Specific ◽  
A Cell ◽  
Cycle Dependent ◽  
Plant Homologue

scholarly journals Functional Complementation of Human Centromere Protein A (CENP-A) by Cse4p from Saccharomyces cerevisiae

2004 ◽  
Vol 24 (15) ◽  
pp. 6620-6630 ◽  
Author(s):  
Gerhard Wieland ◽  
Sandra Orthaus ◽  
Sabine Ohndorf ◽  
Stephan Diekmann ◽  
Peter Hemmerich
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Cell Cycle Arrest ◽  
Budding Yeast ◽  
Protein A ◽  
Human Cells ◽  
Cycle Arrest ◽  
Centromere Protein ◽  
Centromere Protein A

ABSTRACT We have employed a novel in vivo approach to study the structure and function of the eukaryotic kinetochore multiprotein complex. RNA interference (RNAi) was used to block the synthesis of centromere protein A (CENP-A) and Clip-170 in human cells. By coexpression, homologous kinetochore proteins from Saccharomyces cerevisiae were then tested for the ability to complement the RNAi-induced phenotypes. Cse4p, the budding yeast CENP-A homolog, was specifically incorporated into kinetochore nucleosomes and was able to complement RNAi-induced cell cycle arrest in CENP-A-depleted human cells. Thus, Cse4p can structurally and functionally substitute for CENP-A, strongly suggesting that the basic features of centromeric chromatin are conserved between yeast and mammals. Bik1p, the budding yeast homolog of human CLIP-170, also specifically localized to kinetochores during mitosis, but Bik1p did not rescue CLIP-170 depletion-induced cell cycle arrest. Generally, the newly developed in vivo complementation assay provides a powerful new tool for studying the function and evolutionary conservation of multiprotein complexes from yeast to humans.

scholarly journals Saccharomyces cerevisiae cdc15 mutants arrested at a late stage in anaphase are rescued by Xenopus cDNAs encoding N-ras or a protein with beta-transducin repeats.

1993 ◽  
Vol 13 (8) ◽  
pp. 4953-4966 ◽  
Author(s):  
W Spevak ◽  
B D Keiper ◽  
C Stratowa ◽  
M J Castañón
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Yeast Cells ◽  
Cell Cycle Gene ◽  
Intracellular Camp ◽  
Temperature Sensitive ◽  
Ras Genes ◽  
Phosphorylation Event ◽  
Dependent Protein ◽  
A Cell

We have constructed a Xenopus oocyte cDNA library in a Saccharomyces cerevisiae expression vector and used this library to isolate genes that can function in yeast cells to suppress the temperature sensitive [corrected] defect of the cdc15 mutation. Two maternally expressed Xenopus cDNAs which fulfill these conditions have been isolated. One of these clones encodes Xenopus N-ras. In contrast to the yeast RAS genes, Xenopus N-ras rescues the cdc15 mutation. Moreover, overexpression of Xenopus N-ras in S. cerevisiae does not activate the RAS-cyclic AMP (cAMP) pathway; rather, it results in decreased levels of intracellular cAMP in both mutant cdc15 and wild-type cells. Furthermore, we show that lowering cAMP levels is sufficient to allow cells with a nonfunctional Cdc15 protein to complete the mitotic cycle. These results suggest that a key step of the cell cycle is dependent upon a phosphorylation event catalyzed by cAMP-dependent protein kinase. The second clone, beta TrCP (beta-transducin repeat-containing protein), encodes a protein of 518 amino acids that shows significant homology to the beta subunits of G proteins in its C-terminal half. In this region, beta Trcp is composed of seven beta-transducin repeats. beta TrCP is not a functional homolog of S. cerevisiae CDC20, a cell cycle gene that also contains beta-transducin repeats and suppresses the cdc15 mutation.

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