scholarly journals Transient cell cycle arrest of Saccharomyces cerevisiae by amino acid analog beta-2-DL-thienylalanine.

1980 ◽  
Vol 141 (1) ◽  
pp. 100-105 ◽  
Author(s):  
D P Bedard ◽  
R A Singer ◽  
G C Johnston
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Amino Acid ◽  
Cell Cycle Arrest ◽  
Cycle Arrest ◽  
Acid Analog ◽  
Amino Acid Analog ◽  
Beta 2

scholarly journals The ORC/Cdc6/MCM2-7 complex facilitates MCM2-7 dimerization during prereplicative complex formation

2013 ◽  
Vol 42 (4) ◽  
pp. 2257-2269 ◽  
Author(s):  
Cecile Evrin ◽  
Alejandra Fernández-Cid ◽  
Alberto Riera ◽  
Juergen Zech ◽  
Pippa Clarke ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Complex Formation ◽  
Cell Cycle Arrest ◽  
Atp Hydrolysis ◽  
Cycle Arrest ◽  
Helicase Loading ◽  
Limiting Step ◽  
Prereplicative Complex ◽  
Dominant Lethality

Abstract The replicative mini-chromosome-maintenance 2–7 (MCM2-7) helicase is loaded in Saccharomyces cerevisiae and other eukaryotes as a head-to-head double-hexamer around origin DNA. At first, ORC/Cdc6 recruits with the help of Cdt1 a single MCM2-7 hexamer to form an ‘initial’ ORC/Cdc6/Cdt1/MCM2-7 complex. Then, on ATP hydrolysis and Cdt1 release, the ‘initial’ complex is transformed into an ORC/Cdc6/MCM2-7 (OCM) complex. However, it remains unclear how the OCM is subsequently converted into a MCM2-7 double-hexamer. Through analysis of MCM2-7 hexamer-interface mutants we discovered a complex competent for MCM2-7 dimerization. We demonstrate that these MCM2-7 mutants arrest during prereplicative complex (pre-RC) assembly after OCM formation, but before MCM2-7 double-hexamer assembly. Remarkably, only the OCM complex, but not the ‘initial’ ORC/Cdc6/Cdt1/MCM2-7 complex, is competent for MCM2-7 dimerization. The MCM2-7 dimer, in contrast to the MCM2-7 double-hexamer, interacts with ORC/Cdc6 and is salt-sensitive, classifying the arrested complex as a helicase-loading intermediate. Accordingly, we found that overexpression of the mutants cause cell-cycle arrest and dominant lethality. Our work identifies the OCM complex as competent for MCM2-7 dimerization, reveals MCM2-7 dimerization as a limiting step during pre-RC formation and defines critical mechanisms that explain how origins are licensed.

scholarly journals Bombyx mori Dihydroorotate Dehydrogenase: Knockdown Inhibits Cell Growth and Proliferation via Inducing Cell Cycle Arrest

2018 ◽  
Vol 19 (9) ◽  
pp. 2581 ◽  
Author(s):  
Erhu Zhao ◽  
Xiaolan Jiang ◽  
Hongjuan Cui
Keyword(s):  
Cell Cycle ◽  
Amino Acid ◽  
Dna Replication ◽  
Cell Growth ◽  
Cell Cycle Arrest ◽  
Bombyx Mori ◽  
Dihydroorotate Dehydrogenase ◽  
Pyrimidine Synthesis ◽  
Cycle Arrest ◽  
Cell Growth And Proliferation

Dihydroorotate dehydrogenase (DHODH), in the de novo pyrimidine biosynthetic pathway, is the fourth enzyme of pyrimidine synthesis and is used to oxidize dihydroorotate and hence to orotat. We cloned and characterized here the dhod of silkworms, Bombyx mori. The full-length cDNA sequence of dhod is 1339 bp, including an open reading frame (ORF) of 1173 bp that encoded a 390 amino acid protein. And two domains were involved in the Dihydroorotate dehydrogenase amino acid sequence of silkworms, Bombyx mori (BmDHODH), namely a DHO_dh domain and a transmembrane domain in N-termina. The silkworm dhod is expressed throughout development and in nine tissues. Moreover, knockdown of the silkworm dhod gene reduced cell growth and proliferation through G2/M phase cell cycle arrest. Similarly, DHODH inhibitor (leflunomide) also reduced cell growth and proliferation, with a significant decrease of cyclin B and cdk2. DHODH is the fourth enzyme of pyrimidine synthesis, so we also found that leflunomide can inhibit, at least in part, the endomitotic DNA replication in silk glands cells. These findings demonstrate that downregulation of BmDHODH inhibits cell growth and proliferation in silkworm cells, and the endomitotic DNA replication in silk gland cells.

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.

Differential transmission of G1 cell cycle arrest and mating signals by Saccharomyces cerevisiae Ste5 mutants in the pheromone pathway

1999 ◽  
Vol 77 (5) ◽  
pp. 459-468
Author(s):  
You-Jeong Choi ◽  
Sun-Hong Kim ◽  
Ki-Sook Park ◽  
Kang-Yell Choi
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Signal Transduction ◽  
Cell Cycle Arrest ◽  
Mitogen Activated Protein Kinase ◽  
Chemical Mutagenesis ◽  
G1 Arrest ◽  
Cycle Arrest ◽  
Isolation And Characterization ◽  
G1 Cell Cycle Arrest

Saccharomyces cerevisiae Ste5 is a scaffold protein that recruits many pheromone signaling molecules to sequester the pheromone pathway from other homologous mitogen-activated protein kinase pathways. G1 cell cycle arrest and mating are two different physiological consequences of pheromone signal transduction and Ste5 is required for both processes. However, the roles of Ste5 in G1 arrest and mating are not fully understood. To understand the roles of Ste5 better, we isolated 150 G1 cell cycle arrest defective STE5 mutants by chemical mutagenesis of the gene. Here, we found that two G1 cell cycle arrest defective STE5 mutants (ste5MD248V and ste5delta-776) retained mating capacity. When overproduced in a wild-type strain, several ste5 mutants also showed different dominant phenotypes for G1 arrest and mating. Isolation and characterization of the mutants suggested separable roles of Ste5 in G1 arrest and mating of S. cerevisiae. In addition, the roles of Asp-248 and Tyr-421, which are important for pheromone signal transduction were further characterized by site-directed mutagenesis studies.Key words: Ste5, Saccharomyces cerevisiae, signal transduction, mating, G1 cell cycle arrest.

scholarly journals The N-Terminal 24 Amino Acids of the p55 Gamma Regulatory Subunit of Phosphoinositide 3-Kinase Binds Rb and Induces Cell Cycle Arrest

2003 ◽  
Vol 23 (5) ◽  
pp. 1717-1725 ◽  
Author(s):  
Xianmin Xia ◽  
Aiwu Cheng ◽  
Damilola Akinmade ◽  
Anne W. Hamburger
Keyword(s):  
Cell Cycle ◽  
Amino Acid ◽  
Cell Cycle Arrest ◽  
Cell Cycle Progression ◽  
Molecular Mechanisms ◽  
Biological Effects ◽  
Cycle Progression ◽  
Regulatory Subunits ◽  
Cycle Arrest ◽  
Phosphoinositide 3 Kinase

ABSTRACT Although phosphoinositide 3-kinase (PI 3-kinase) is essential for cell cycle progression, the molecular mechanisms that regulate its diverse biological effects are poorly understood. We demonstrate here that Rb, a key regulator of cell cycle progression, associates with p55 kDa (p55α and p55γ) regulatory subunits of PI 3-kinase in vivo and in vitro. Both confocal microscopy and biochemical analysis demonstrated the presence of p55γ in the nucleus. The 24-amino-acid N-terminal end of p55γ, which is unique among PI 3-kinase regulatory subunits, was sufficient to bind Rb. Addition of serum or growth factors to quiescent cells triggered the dissociation of Rb from p55. Ectopic expression of the 24-amino-acid N-terminal end of p55γ inhibited cell cycle progression, as evidenced by induction of cell growth arrest at the G0/G1 phase, inhibition of DNA synthesis, inhibition of cyclin D and cyclin E promoter activity, and changes in the expression of cell cycle-related proteins. The inhibitory effects of the N-terminal end of p55γ on cell cycle progression depended on the presence of functional Rb. These data demonstrate for the first time an association of p55γ with Rb and show that modification of this association can lead to cell cycle arrest.

Sign in / Sign up

Export Citation Format

Share Document