The role of PDR13 in tolerance to high copper stress in budding yeast

FEBS Letters ◽  
2001 ◽  
Vol 508 (1) ◽  
pp. 99-102 ◽  
Author(s):  
Do-Young Kim ◽  
Won-Yong Song ◽  
Young-Yell Yang ◽  
Youngsook Lee
Genes ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 844
Author(s):  
Sergio Barahona ◽  
Juan Castro-Severyn ◽  
Cristina Dorador ◽  
Claudia Saavedra ◽  
Francisco Remonsellez

The use of microorganisms in mining processes is a technology widely employed around the world. Leaching bacteria are characterized by having resistance mechanisms for several metals found in their acidic environments, some of which have been partially described in the Acidithiobacillus genus (mainly on ferrooxidans species). However, the response to copper has not been studied in the psychrotolerant Acidithiobacillus ferrivorans strains. Therefore, we propose to elucidate the response mechanisms of A. ferrivorans ACH to high copper concentrations (0–800 mM), describing its genetic repertoire and transcriptional regulation. Our results show that A. ferrivorans ACH can grow in up to 400 mM of copper. Moreover, we found the presence of several copper-related makers, belonging to cop and cus systems, as well as rusticyanins and periplasmatic acop protein in the genome. Interestingly, the ACH strain is the only one in which we find three copies of copB and copZ genes. Moreover, transcriptional expression showed an up-regulation response (acop, copZ, cusA, rusA, and rusB) to high copper concentrations. Finally, our results support the important role of these genes in A. ferrivorans copper stress resistance, promoting the use of the ACH strain in industrial leaching under low temperatures, which could decrease the activation times of oxidation processes and the energy costs.


2011 ◽  
Vol 8 (61) ◽  
pp. 1128-1141 ◽  
Author(s):  
P. K. Vinod ◽  
Paula Freire ◽  
Ahmed Rattani ◽  
Andrea Ciliberto ◽  
Frank Uhlmann ◽  
...  

The operating principles of complex regulatory networks are best understood with the help of mathematical modelling rather than by intuitive reasoning. Hereby, we study the dynamics of the mitotic exit (ME) control system in budding yeast by further developing the Queralt's model. A comprehensive systems view of the network regulating ME is provided based on classical experiments in the literature. In this picture, Cdc20–APC is a critical node controlling both cyclin (Clb2 and Clb5) and phosphatase (Cdc14) branches of the regulatory network. On the basis of experimental situations ranging from single to quintuple mutants, the kinetic parameters of the network are estimated. Numerical analysis of the model quantifies the dependence of ME control on the proteolytic and non-proteolytic functions of separase. We show that the requirement of the non-proteolytic function of separase for ME depends on cyclin-dependent kinase activity. The model is also used for the systematic analysis of the recently discovered Cdc14 endocycles. The significance of Cdc14 endocycles in eukaryotic cell cycle control is discussed as well.


Nature ◽  
10.1038/32695 ◽  
1998 ◽  
Vol 392 (6673) ◽  
pp. 303-306 ◽  
Author(s):  
Masaki Mizunuma ◽  
Dai Hirata ◽  
Kohji Miyahara ◽  
Eiko Tsuchiya ◽  
Tokichi Miyakawa
Keyword(s):  

2019 ◽  
Vol 20 (3) ◽  
pp. 575 ◽  
Author(s):  
Saleh Alquethamy ◽  
Marjan Khorvash ◽  
Victoria Pederick ◽  
Jonathan Whittall ◽  
James Paton ◽  
...  

Acinetobacter baumannii has emerged as one of the leading causative agents of nosocomial infections. Due to its high level of intrinsic and adapted antibiotic resistance, treatment failure rates are high, which allows this opportunistic pathogen to thrive during infection in immune-compromised patients. A. baumannii can cause infections within a broad range of host niches, with pneumonia and bacteraemia being associated with the greatest levels of morbidity and mortality. Although its resistance to antibiotics is widely studied, our understanding of the mechanisms required for dealing with environmental stresses related to virulence and hospital persistence, such as copper toxicity, is limited. Here, we performed an in silico analysis of the A. baumannii copper resistome, examining its regulation under copper stress. Using comparative analyses of bacterial P-type ATPases, we propose that A. baumannii encodes a member of a novel subgroup of P1B-1 ATPases. Analyses of three putative inner membrane copper efflux systems identified the P1B-1 ATPase CopA as the primary mediator of cytoplasmic copper resistance in A. baumannii. Using a murine model of A. baumannii pneumonia, we reveal that CopA contributes to the virulence of A. baumannii. Collectively, this study advances our understanding of how A. baumannii deals with environmental copper toxicity, and it provides novel insights into how A. baumannii combats adversities encountered as part of the host immune defence.


2003 ◽  
Vol 23 (23) ◽  
pp. 8729-8739 ◽  
Author(s):  
Sarit Smolikov ◽  
Anat Krauskopf

ABSTRACT Telomeres are nucleoprotein structures that cap the ends of chromosomes and thereby protect their stability and integrity. In the presence of telomerase, the enzyme that synthesizes telomeric repeats, telomere length is controlled primarily by Rap1p, the budding yeast telomeric DNA binding protein which, through its C-terminal domain, nucleates a protein complex that limits telomere lengthening. In the absence of telomerase, telomeres shorten with every cell division, and eventually, cells enter replicative senescence. We have set out to identify the telomeric property that determines the replicative capacity of telomerase-deficient budding yeast. We show that in cells deficient for both telomerase and homologous recombination, replicative capacity is dependent on telomere length but not on the binding of Rap1p to the telomeric repeats. Strikingly, inhibition of Rap1p binding or truncation of the C-terminal tail of Rap1p in Kluyveromyces lactis and deletion of the Rap1p-recruited complex in Saccharomyces cerevisiae lead to a dramatic increase in replicative capacity. The study of the role of telomere binding proteins and telomere length on replicative capacity in yeast may have significant implications for our understanding of cellular senescence in higher organisms.


PLoS ONE ◽  
2012 ◽  
Vol 7 (2) ◽  
pp. e30810 ◽  
Author(s):  
Baris Hancioglu ◽  
John J. Tyson

1999 ◽  
Vol 10 (2) ◽  
pp. 283-296 ◽  
Author(s):  
Katie B. Shannon ◽  
Rong Li

The budding yeast IQGAP-like protein Cyk1p/Iqg1p localizes to the mother-bud junction during anaphase and has been shown to be required for the completion of cytokinesis. In this study, video microscopy analysis of cells expressing green fluorescent protein-tagged Cyk1p/Iqg1p demonstrates that Cyk1p/Iqg1p is a dynamic component of the contractile ring during cytokinesis. Furthermore, in the absence of Cyk1p/Iqg1p, myosin II fails to undergo the contraction-like size change at the end of mitosis. To understand the mechanistic role of Cyk1p/Iqg1p in actomyosin ring assembly and dynamics, we have investigated the role of the structural domains that Cyk1p/Iqg1p shares with IQGAPs. An amino terminal portion containing the calponin homology domain binds to actin filaments and is required for the assembly of actin filaments to the ring. This result supports the hypothesis that Cyk1p/Iqg1p plays a direct role in F-actin recruitment. Deletion of the domain harboring the eight IQ motifs abolishes the localization of Cyk1p/Iqg1p to the bud neck, suggesting that Cyk1p/Iqg1p may be localized through interactions with a calmodulin-like protein. Interestingly, deletion of the COOH-terminal GTPase-activating protein-related domain does not affect Cyk1p/Iqg1p localization or actin recruitment to the ring but prevents actomyosin ring contraction. In vitro binding experiments show that Cyk1p/Iqg1p binds to calmodulin, Cmd1p, in a calcium-dependent manner, and to Tem1p, a small GTP-binding protein previously found to be required for the completion of anaphase. These results demonstrate the critical function of Cyk1p/Iqg1p in regulating various steps of actomyosin ring assembly and cytokinesis.


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