scholarly journals Role of Four Calcium Transport Proteins, Encoded bynca-1,nca-2,nca-3, andcax, in Maintaining Intracellular Calcium Levels in Neurospora crassa

2011 ◽  
Vol 10 (5) ◽  
pp. 654-661 ◽  
Author(s):  
Barry J. Bowman ◽  
Stephen Abreu ◽  
Emilio Margolles-Clark ◽  
Marija Draskovic ◽  
Emma Jean Bowman
Keyword(s):  
Neurospora Crassa ◽  
Calcium Transport ◽  
High Speed ◽  
Transport Proteins ◽  
Cell Fractionation ◽  
Animal Cells ◽  
Normal Medium ◽  
Content Type ◽  
Cell Fractions

ABSTRACTWe have examined the distribution of calcium inNeurospora crassaand investigated the role of four predicted calcium transport proteins. The results of cell fractionation experiments showed 4% of cellular calcium in mitochondria, approximately 11% in a dense vacuolar fraction, 40% in an insoluble form that copurifies with microsomes, and 40% in a high-speed supernatant, presumably from large vacuoles that had broken. Strains lacking NCA-1, a SERCA-type Ca2+-ATPase, or NCA-3, a PMC-type Ca2+-ATPase, had no obvious defects in growth or distribution of calcium. A strain lacking NCA-2, which is also a PMC-type Ca2+-ATPase, grew slowly in normal medium and was unable to grow in high concentrations of calcium tolerated by the wild type. Furthermore, when grown in normal concentrations of calcium (0.68 mM), this strain accumulated 4- to 10-fold more calcium than other strains, elevated in all cell fractions. The data suggest that NCA-2 functions in the plasma membrane to pump calcium out of the cell. In this way, it resembles the PMC-type enzymes of animal cells, not the Pmc1p enzyme inSaccharomyces cerevisiaethat resides in the vacuole. Strains lacking thecaxgene, which encodes a Ca2+/H+exchange protein in vacuolar membranes, accumulate very little calcium in the dense vacuolar fraction but have normal levels of calcium in other fractions. Thecaxknockout strain has no other observable phenotypes. These data suggest that “the vacuole” is heterogeneous and that the dense vacuolar fraction contains an organelle that is dependent upon the CAX transporter for accumulation of calcium, while other components of the vacuolar system have multiple calcium transporters.

scholarly journals hfqPlays Important Roles in Virulence and Stress Adaptation in Cronobacter sakazakii ATCC 29544

2015 ◽  
Vol 83 (5) ◽  
pp. 2089-2098 ◽  
Author(s):  
Seongok Kim ◽  
Hyelyeon Hwang ◽  
Kwang-Pyo Kim ◽  
Hyunjin Yoon ◽  
Dong-Hyun Kang ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Bacterial Species ◽  
Soft Agar ◽  
Host Cells ◽  
Neonatal Meningitis ◽  
Animal Cells ◽  
Content Type ◽  
Flagellar Biosynthesis

Cronobacterspp. are opportunistic pathogens that cause neonatal meningitis and sepsis with high mortality in neonates. Despite the peril associated withCronobacterinfection, the mechanisms of pathogenesis are still being unraveled. Hfq, which is known as an RNA chaperone, participates in the interaction with bacterial small RNAs (sRNAs) to regulate posttranscriptionally the expression of various genes. Recent studies have demonstrated that Hfq contributes to the pathogenesis of numerous species of bacteria, and its roles are varied between bacterial species. Here, we tried to elucidate the role of Hfq inC. sakazakiivirulence. In the absence ofhfq,C. sakazakiiwas highly attenuated in disseminationin vivo, showed defects in invasion (3-fold) into animal cells and survival (103-fold) within host cells, and exhibited low resistance to hydrogen peroxide (102-fold). Remarkably, the loss ofhfqled to hypermotility on soft agar, which is contrary to what has been observed in other pathogenic bacteria. The hyperflagellated bacteria were likely to be attributable to the increased transcription of genes associated with flagellar biosynthesis in a strain lackinghfq. Together, these data strongly suggest thathfqplays important roles in the virulence ofC. sakazakiiby participating in the regulation of multiple genes.

China's economy will struggle to halt secular slowdown

2021 ◽  
Keyword(s):  
High Speed ◽  
Regression To The Mean ◽  
Content Type ◽  
Strong Force ◽  
Global Demand ◽  
The Mean ◽  
Productivity Gains ◽  
Global Growth ◽  
China’S Economy

Significance Comparisons with two formerly fast-growing Asian neighbours, Japan and South Korea, suggest that China will continue to slow for another decade. Analysis of global growth trends over 50 years points to a strong force of ‘regression to the mean’, meaning that continued high-speed growth is statistically unlikely. Impacts Continued Chinese economic slowing will reduce global demand for resources such as iron ore and coal. Achieving productivity growth will require deepening reforms to increase the role of the market, the private sector and competition. World Bank economists emphasise that imposing stricter financial discipline is a key step to enhancing market-based productivity gains.

Estrogen Regulates Duodenal Calcium Absorption Through Differential Role of Estrogen Receptor on Calcium Transport Proteins

2020 ◽  
Vol 65 (12) ◽  
pp. 3502-3513 ◽  
Author(s):  
Xubiao Nie ◽  
Hai Jin ◽  
Guorong Wen ◽  
Jingyu Xu ◽  
Jiaxing An ◽  
...  
Keyword(s):  
Estrogen Receptor ◽  
Calcium Transport ◽  
Calcium Absorption ◽  
Transport Proteins

scholarly journals Neurospora crassa NKIN2, a Kinesin-3 Motor, Transports Early Endosomes and Is Required for Polarized Growth

2013 ◽  
Vol 12 (7) ◽  
pp. 1020-1032 ◽  
Author(s):  
Constanze Seidel ◽  
Sergio David Moreno-Velásquez ◽  
Meritxell Riquelme ◽  
Reinhard Fischer
Keyword(s):  
Neurospora Crassa ◽  
Fluorescent Protein ◽  
Early Endosome ◽  
Mechanical Forces ◽  
Structural Components ◽  
Content Type ◽  
Early Endosomes ◽  
Polarized Cells ◽  
Green Fluorescent

ABSTRACT Biological motors are molecular nanomachines, which convert chemical energy into mechanical forces. The combination of mechanoenzymes with structural components, such as the cytoskeleton, enables eukaryotic cells to overcome entropy, generate molecular gradients, and establish polarity. Hyphae of filamentous fungi are among the most polarized cells, and polarity defects are most obvious. Here, we studied the role of the kinesin-3 motor, NKIN2, in Neurospora crassa . We found that NKIN2 localizes as fast-moving spots in the cytoplasm of mature hyphae. To test whether the spots represented early endosomes, the Rab5 GTPase YPT52 was used as an endosomal marker. NKIN2 colocalized with YPT52. Deletion of nkin2 caused strongly reduced endosomal movement. Combined, these results confirm the involvement of NKIN2 in early endosome transport. Introduction of a rigor mutation into NKIN2 labeled with green fluorescent protein (GFP) resulted in decoration of microtubules. Interestingly, NKIN2 rigor was associated with a subpopulation of microtubules, as had been shown earlier for the Aspergillus nidulans orthologue UncA. Other kinesins did not show this specificity.

A high-speed world with fake news: brand managers take warning

2019 ◽  
Vol 29 (2) ◽  
pp. 234-245 ◽  
Author(s):  
Mark Peterson
Keyword(s):  
Scientific Method ◽  
High Speed ◽  
Time Frame ◽  
The Internet ◽  
Activity Levels ◽  
Fake News ◽  
Content Type ◽  
Sudden Rise ◽  
Practical Implications

Purpose In an increasingly dangerous era for brands because of the emergence of fake news on the internet, brand managers need to know what is happening with fake news. This study aims to present perspectives on how to cope in an era of fake news. Design/methodology/approach The author provides a general review of fake news and what its sudden rise means for brand managers. Findings The study highlights the importance of context for news and the role of institutions, such as businesses and governments. The study calls brand managers to slow down in the high-speed world of the infosphere to preserve the integrity of their brands. Research limitations/implications The study is limited by its time frame as the internet continues to evolve. However, for times when fake news presents a threat to brands and other institutions, the study is relevant. Practical implications Brand managers need to slow down their activity levels just as savvy readers need to slow down their own reading on the internet. By doing this, brand managers will be better able to defend their brands in an era characterized by volatility, uncertainty, complexity and ambiguity (VUCA). Social implications The study suggests that resistance to fake news and its pernicious effects can be improved by taking an approach to processing content on the internet characterized by the scientific method. In this way, a context for news can be derived and fake news can be identified. In this way, societal trust can be improved. Originality/value This study is original because it analyzes the implications of fake news for brand managers and presents the most workable steps for identifying fake news.

scholarly journals The Oxygenase CAO-1 of Neurospora crassa Is a Resveratrol Cleavage Enzyme

2013 ◽  
Vol 12 (9) ◽  
pp. 1305-1314 ◽  
Author(s):  
Violeta Díaz-Sánchez ◽  
Alejandro F. Estrada ◽  
M. Carmen Limón ◽  
Salim Al-Babili ◽  
Javier Avalos
Keyword(s):  
Neurospora Crassa ◽  
Sequence Similarity ◽  
Hydroxyl Groups ◽  
Mrna Levels ◽  
Pronounced Increase ◽  
Content Type ◽  
Carotenoid Metabolism ◽  
Cleavage Enzyme ◽  
Β Carotene

ABSTRACT The genome of the ascomycete Neurospora crassa encodes CAO-1 and CAO-2, two members of the carotenoid cleavage oxygenase family that target double bonds in different substrates. Previous studies demonstrated the role of CAO-2 in cleaving the C 40 carotene torulene, a key step in the synthesis of the C 35 apocarotenoid pigment neurosporaxanthin. In this work, we investigated the activity of CAO-1, assuming that it may provide retinal, the chromophore of the NOP-1 rhodopsin, by cleaving β-carotene. For this purpose, we tested CAO-1 activity with carotenoid substrates that were, however, not converted. In contrast and consistent with its sequence similarity to family members that act on stilbenes, CAO-1 cleaved the interphenyl Cα-Cβ double bond of resveratrol and its derivative piceatannol. CAO-1 did not convert five other similar stilbenes, indicating a requirement for a minimal number of unmodified hydroxyl groups in the stilbene background. Confirming its biological function in converting stilbenes, adding resveratrol led to a pronounced increase in cao-1 mRNA levels, while light, a key regulator of carotenoid metabolism, did not alter them. Targeted Δ cao-1 mutants were not impaired by the presence of resveratrol, a phytoalexin active against different fungi, which did not significantly affect the growth and development of wild-type Neurospora . However, under partial sorbose toxicity, the Δ cao-1 colonies exhibited faster radial growth than control strains in the presence of resveratrol, suggesting a moderate toxic effect of resveratrol cleavage products.

Game-speed influence and brand attitude: mediating role of thought favorability in in-game advertising

2018 ◽  
Vol 8 (1) ◽  
pp. 99-112 ◽  
Author(s):  
Devika Vashisht ◽  
Surinder Mohan
Keyword(s):  
High Speed ◽  
Online Advertising ◽  
Brand Attitude ◽  
Content Type ◽  
Mediating Role ◽  
Capacity Model ◽  
Heuristic Systematic Model ◽  
Brand Placements ◽  
Game Developers

Purpose The purpose of this paper is to investigate the effect of game-speed on brand attitude and mediating role of thought favorability in the speed-attitude relationship in the context of in-game advertising (IGA). Specifically, this investigation employs the Limited Capacity Model of Attention and the heuristic-systematic model to explain the conditions under which in-game brand placements form favorable or unfavorable thoughts about the game and the embedded brand, and subsequent brand attitude. Design/methodology/approach In total, 78 student-gamers participated in the study. One-tailed independent-samples t-tests and a path analysis were used for hypothesis testing. Findings Results revealed that fast-paced games resulted in higher thought favorability and more favorable brand attitude than the slow-paced games. Furthermore, the results also showed that thought favorability mediated the relationship of game-speed and brand attitude among Indian gamers. Research limitations/implications This paper adds to advertising literature from a non-traditional advertising perspective, primarily in the context of IGA, and explains the role played by game-speed as an antecedent to thought favorability that adds value to thought favorability and brand attitude relationship. Also, the study provides an important implication for the marketers that to generate more positive brand attitudes and high favorable thoughts, advertisers and game-developers must focus on high-speed games. Originality/value This study is the first in its stream toward understanding the mediating role of thought favorability in determining the persuasion effect on Indian gamers’ brand attitude in the context of online advertising from attention and elaboration perspectives.

scholarly journals Physiological Role of Acyl Coenzyme A Synthetase Homologs in Lipid Metabolism in Neurospora crassa

2013 ◽  
Vol 12 (9) ◽  
pp. 1244-1257 ◽  
Author(s):  
Christine M. Roche ◽  
Harvey W. Blanch ◽  
Douglas S. Clark ◽  
N. Louise Glass
Keyword(s):  
Neurospora Crassa ◽  
Metabolic Pathways ◽  
Lipid Membrane ◽  
Coenzyme A ◽  
De Novo ◽  
Physiological Role ◽  
Functional Redundancy ◽  
Content Type ◽  
Acyl Coenzyme A

ABSTRACTAcyl coenzyme A (CoA) synthetase (ACS) enzymes catalyze the activation of free fatty acids (FAs) to CoA esters by a two-step thioesterification reaction. Activated FAs participate in a variety of anabolic and catabolic lipid metabolic pathways, includingde novocomplex lipid biosynthesis, FA β-oxidation, and lipid membrane remodeling. Analysis of the genome sequence of the filamentous fungusNeurospora crassaidentified seven putative fatty ACSs (ACS-1 through ACS-7). ACS-3 was found to be the major activator for exogenous FAs for anabolic lipid metabolic pathways, and consistent with this finding, ACS-3 localized to the endoplasmic reticulum, plasma membrane, and septa. Double-mutant analyses confirmed partial functional redundancy of ACS-2 and ACS-3. ACS-5 was determined to function in siderophore biosynthesis, indicating alternative functions for ACS enzymes in addition to fatty acid metabolism. TheN. crassaACSs involved in activation of FAs for catabolism were not specifically defined, presumably due to functional redundancy of several of ACSs for catabolism of exogenous FAs.

A Statistical Study of Process Variables to Optimize a High Speed Curtain Coater: Part I

TAPPI Journal ◽  
2009 ◽  
Vol 8 (1) ◽  
pp. 20-26 ◽  
Author(s):  
PEEYUSH TRIPATHI ◽  
MARGARET JOYCE ◽  
PAUL D. FLEMING ◽  
MASAHIRO SUGIHARA
Keyword(s):  
Boundary Layer ◽  
Experimental Design ◽  
High Speed ◽  
Statistical Study ◽  
Process Variables ◽  
High Speeds ◽  
The Stability ◽  
Air Removal ◽  
Removal System

Using an experimental design approach, researchers altered process parameters and material prop-erties to stabilize the curtain of a pilot curtain coater at high speeds. Part I of this paper identifies the four significant variables that influence curtain stability. The boundary layer air removal system was critical to the stability of the curtain and base sheet roughness was found to be very important. A shear thinning coating rheology and higher curtain heights improved the curtain stability at high speeds. The sizing of the base sheet affected coverage and cur-tain stability because of its effect on base sheet wettability. The role of surfactant was inconclusive. Part II of this paper will report on further optimization of curtain stability with these four variables using a D-optimal partial-facto-rial design.

Sign in / Sign up

Export Citation Format

Share Document