scholarly journals The Effects of Copper Stress and the Involved Role of Ethylene on the Growth and Physiological Metabolism of Catharanthus roseus

2015 ◽  
Vol 04 (03) ◽  
pp. 47-57
Author(s):  
灵 刘
Keyword(s):  
Catharanthus Roseus ◽  
Copper Stress ◽  
Physiological Metabolism

scholarly journals The Role of the CopA Copper Efflux System in Acinetobacter baumannii Virulence

2019 ◽  
Vol 20 (3) ◽  
pp. 575 ◽  
Author(s):  
Saleh Alquethamy ◽  
Marjan Khorvash ◽  
Victoria Pederick ◽  
Jonathan Whittall ◽  
James Paton ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Copper Toxicity ◽  
In Silico Analysis ◽  
Opportunistic Pathogen ◽  
Copper Resistance ◽  
Copper Stress ◽  
Causative Agents ◽  
High Level ◽  
P Type

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.

Characterization of Hexokinase and Fructokinase from Suspension-Cultured Catharanthus roseus Cells

1988 ◽  
Vol 43 (11-12) ◽  
pp. 827-834 ◽  
Author(s):  
Yüko Yamashita ◽  
Hiroshi Ashihara
Keyword(s):  
Catharanthus Roseus ◽  
Divalent Cations ◽  
Ph Optimum ◽  
Optimum Ph ◽  
Phosphate Donor

Abstract Two different hexose-phosphorylating enzymes, hexokinase and fructokinase, were partially purified from suspension-cultured Catharanthus roseus cells. One of the enzymes, hexokinase, catalyzed the phosphorylation of both glucose and fructose. The Km values for glucose and fructose were 0.06 mM and 0.23 mM, respectively. The Vmax of the enzyme with fructose was approximately three times higher than with glucose. This enzyme was specific in its requirement for ATP and its Km value for ATP was 52 μM. The optimum pH was 8.0 and Mg2+ or Mn2+ was required for the activity. The activity was inhibited by considerably higher concentrations of ADP (i.e., 4 mM ADP was required for 50% inhibition). The second enzyme, fructokinase, was specific for fructose, and no activity was detected with glucose as substrate. This enzyme used UTP or CTP as phosphate donor. The Km values of this enzyme for fructose and UTP were 0.13 mM and 0.15 mM, respectively. The pH optimum was 7.2, and Mg2+ or Mn2+ was required for the activity. These divalent cations could be partially replaced by Ca2+. The activity was inhibited noncompetitively by ADP and AMP. 90% inhibition of the activity by 0.5 mM ADP was observed in the presence of 2 mM UTP and 5 mM MgCl2. Fructose-2,6-bisphosphate, glucose-1,6-bisphosphate, glucose-6-phosphate, and fructose-6-phosphate had little or no effect on the activity of both the hexokinase and the fructokinase. Based on these results, a discussion is presented of the role of hexokinase and fructokinase and their involvement in the regulation of the metabolism of sugars in Catharanthus cells.

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
Keyword(s):  
Budding Yeast ◽  
Copper Stress ◽  
High Copper

Role of the ubiquitin-proteasome pathway and some peptidases during seed germination and copper stress in bean cotyledons

2014 ◽  
Vol 76 ◽  
pp. 77-85 ◽  
Author(s):  
Inès Karmous ◽  
Abdelilah Chaoui ◽  
Khadija Jaouani ◽  
David Sheehan ◽  
Ezzedine El Ferjani ◽  
...  
Keyword(s):  
Seed Germination ◽  
Copper Stress ◽  
Ubiquitin Proteasome Pathway ◽  
Ubiquitin Proteasome ◽  
Proteasome Pathway

Possible role of adenylates in the engagement of the cyanide-resistant pathway in nutrient-starved Catharanthus roseus cells

1994 ◽  
Vol 90 (2) ◽  
pp. 269-278 ◽  
Author(s):  
Marcel H. N. Hoefnagel ◽  
Frank Van Iren ◽  
Kees R. Libbenga ◽  
Linus H. W. Van der Plas
Keyword(s):  
Catharanthus Roseus

scholarly journals A novel function of M. tuberculosis chaperonin paralog GroEL1 in copper homeostasis

2019 ◽  
Author(s):  
Mohammed Yousuf Ansari ◽  
Sakshi D. Batra ◽  
Hina Ojha ◽  
Ashish ◽  
Jaya S. Tyagi ◽  
...  
Keyword(s):  
Dna Damage ◽  
Functional Divergence ◽  
Cellular Protein ◽  
Copper Stress ◽  
Titration Calorimetry ◽  
Evolutionary Divergence ◽  
Wild Type ◽  
Knock Out

AbstractMycobacterial GroELs namely GroEL1 and GroEL2 belong to the family of molecular chaperones, chaperonins. Chaperonins in Escherichia coli are termed as GroEL and GroES which are encoded by essential genes and are involved in cellular protein folding. GroEL1 has a characteristic Histidine-rich C-terminus contrary to its essential paralog GroEL2 and E. coli GroEL which have hydrophobic (GGM) repeats. Since Histidine richness is likely to be involved in metal binding, in this study we have attempted to decipher the role of GroEL1 protein in chelating metals and the consequent role on M. tuberculosis physiology. Using isothermal titration calorimetry (ITC), we found that GroEL1 binds copper, nickel and cobalt, with the highest binding affinity to copper. Since copper is known to be toxic at higher concentration, we cultured Wild Type M. tuberculosis H37Rv, groEL1 knock-out and groEL1-complemented strain with increasing concentrations of copper. We found that M. tuberculosis groEL1 knock out strain is more sensitive to copper than the wild type. Further hypothesizing that the probable mode of action of copper is by induction of oxidative stress, we attempted to understand the role of GroEL1 in redox silencing and hydroxyl radical mediated DNA damage. We interestingly found through our in vitro studies that GroEL1 is helpful in protection from copper stress through maintaining redox balance and free radical mediated DNA damage. Thus, these results indicate that the duplication of chaperonin genes in M. tuberculosis might have led to their evolutionary divergence and resulted in a functional divergence of chaperonins.

scholarly journals OsMSR3, a Small Heat Shock Protein, Confers Enhanced Tolerance to Copper Stress in Arabidopsis thaliana

2019 ◽  
Vol 20 (23) ◽  
pp. 6096 ◽  
Author(s):  
Yanchun Cui ◽  
Manling Wang ◽  
Xuming Yin ◽  
Guoyun Xu ◽  
Shufeng Song ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Growth And Development ◽  
Oryza Sativa L ◽  
Metal Resistance ◽  
Copper Stress ◽  
Cu Stress ◽  
Responsive Gene

Copper is a mineral element essential for the normal growth and development of plants; however, excessive levels can severely affect plant growth and development. Oryza sativa L. multiple stress-responsive gene 3 (OsMSR3) is a small, low-molecular-weight heat shock protein (HSP) gene. A previous study has shown that OsMSR3 expression improves the tolerance of Arabidopsis to cadmium stress. However, the role of OsMSR3 in the Cu stress response of plants remains unclear, and, thus, this study aimed to elucidate this phenomenon in Arabidopsis thaliana, to further understand the role of small HSPs (sHSPs) in heavy metal resistance in plants. Under Cu stress, transgenic A. thaliana expressing OsMSR3 showed higher tolerance to Cu, longer roots, higher survival rates, biomass, and relative water content, and accumulated more Cu, abscisic acid (ABA), hydrogen peroxide, chlorophyll, carotenoid, superoxide dismutase, and peroxidase than wild-type plants did. Moreover, OsMSR3 expression in A. thaliana increased the expression of antioxidant-related and ABA-responsive genes. Collectively, our findings suggest that OsMSR3 played an important role in regulating Cu tolerance in plants and improved their tolerance to Cu stress through enhanced activation of antioxidative defense mechanisms and positive regulation of ABA-responsive gene expression.

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