scholarly journals Thioredoxin-dependent control balances the metabolic activities of tetrapyrrole biosynthesis

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Daniel Wittmann ◽  
Neha Sinha ◽  
Bernhard Grimm
Keyword(s):  
Environmental Changes ◽  
Nuclear Gene ◽  
Tetrapyrrole Biosynthesis ◽  
Nuclear Gene Expression ◽  
Light Levels ◽  
Organ Specific ◽  
Intracellular Compartments ◽  
The Face ◽  
Metabolic Activities ◽  
The Impact

AbstractPlastids are specialized organelles found in plants, which are endowed with their own genomes, and differ in many respects from the intracellular compartments of organisms belonging to other kingdoms of life. They differentiate into diverse, plant organ-specific variants, and are perhaps the most versatile organelles known. Chloroplasts are the green plastids in the leaves and stems of plants, whose primary function is photosynthesis. In response to environmental changes, chloroplasts use several mechanisms to coordinate their photosynthetic activities with nuclear gene expression and other metabolic pathways. Here, we focus on a redox-based regulatory network composed of thioredoxins (TRX) and TRX-like proteins. Among multiple redox-controlled metabolic activities in chloroplasts, tetrapyrrole biosynthesis is particularly rich in TRX-dependent enzymes. This review summarizes the effects of plastid-localized reductants on several enzymes of this pathway, which have been shown to undergo dithiol-disulfide transitions. We describe the impact of TRX-dependent control on the activity, stability and interactions of these enzymes, and assess its contribution to the provision of adequate supplies of metabolic intermediates in the face of diurnal and more rapid and transient changes in light levels and other environmental factors.

scholarly journals Dual-targeted transcription factors are required for optimal photosynthesis and stress responses in Arabidopsis thaliana

2019 ◽  
Author(s):  
Piotr Gawroński ◽  
Paweł Burdiak ◽  
Lars B. Scharff ◽  
Jakub Mielecki ◽  
Magdalena Zaborowska ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Stress Responses ◽  
Environmental Changes ◽  
Cell Function ◽  
Nuclear Gene ◽  
Transit Peptide ◽  
Protein Translation ◽  
Retrograde Signaling ◽  
Nuclear Gene Expression ◽  
Chloroplast Translation

SummaryChloroplast to nucleus retrograde signaling is essential for cell function, acclimation to fluctuating environmental conditions, plant growth and development. The vast majority of chloroplast proteins are nuclear-encoded and must be imported into the organelle after synthesis in the cytoplasm. This import is essential for the development of fully functional chloroplasts. On the other hand, functional chloroplasts act as sensors of environmental changes and can trigger acclimatory responses that influence nuclear gene expression. Signaling via mobile transcription factors (TFs) has been recently recognized as a way of communication between organelles and the nucleus. In this study, we performed a targeted reverse genetic screen to identify novel dual-localized TFs involved in chloroplast retrograde signaling during stress responses. We found that CHLOROPLAST IMPORT APPARATUS 2 (CIA2), a TF with putative plastid transit peptide can be detected in chloroplasts and the nucleus. Further, we found that CIA2, along with its homolog CIA2-like (CIL) act in an unequally redundant manner and are involved in the regulation of Arabidopsis responses to UV-AB, high light, and heat shock. Finally, our results suggest that both CIA2 and CIL are crucial for chloroplast translation. Our results contribute to a deeper understanding of signaling events in the chloroplast-nucleus cross-talk.SignificanceWe found that a transcription factor CIA2 can be located in chloroplasts and nucleus. CIA2 and is close homolog CIL are involved in protein translation and abiotic stress responses, and we suggest that they play an essential role in retrograde signaling between these organelles.

Mitochondrial Physiology in Health and Disease: Changes with Aging.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. SCI-1-SCI-1
Author(s):  
Douglas C. Wallace
Keyword(s):  
Conflicts Of Interest ◽  
Nuclear Gene ◽  
High Energy ◽  
Structural Defects ◽  
Degenerative Diseases ◽  
Tissue Specific ◽  
Nuclear Gene Expression ◽  
Age Related ◽  
The Face ◽  
And Function

Abstract Abstract SCI-1 The incidence and cost of the age-related metabolic and degenerative diseases is rising in the face of ever increasing investment. Therefore, something must be missing in our current hypotheses about these diseases. Until now, the prevailing paradigms in Western medicine have been the anatomical paradigm of disease which posits that tissue-specific symptoms are due to tissue-specific structural defects and the Mendelian paradigm of genetics which posits that if a disease is inherited according to the Laws of Mendel it is genetic and if not it is environmental. The epigenome is invoked to explain the environmental modulation of the nuclear gene expression. However, life requires both structure and energy and the over 1500 mitochondrial energy genes are dispersed across the chromosomes plus the maternally inherited mitochondrial DNA. Moreover, the cells and tissues most affected by aging and the age-related disease are those most reliant on mitochondrial energy and the mitochondrial lies at the interface between environmental calories and human physiology, diabetes and obesity. The epigenome and the signal transduction pathways are regulated by protein phosphorylation by ATP, acetylation via acetyl-CoA, and methylation by S-adenosylmethionine, all driven by mitochondrial high energy substrates modulated by available calories. Furthermore, mitochondrial redox chemistry regulates reactive oxygen production and thiol/disulfide chemistry and these also regulate cellular signaling and function. Therefore, bioenergetics and mitochondrial genetics are the missing factors which have inhibited our capacity of address the biology and genetics of the age-related metabolic and degenerative diseases, cancer and aging. Disclosures No relevant conflicts of interest to declare.

The cytoskeleton and nucleus: the role of actin as a modulator of neuronal gene expression

e-Neuroforum ◽  
2011 ◽  
Vol 17 (1) ◽  
pp. 1-5 ◽  
Author(s):  
B. Knöll ◽  
H. Beck
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Serum Response Factor ◽  
Nuclear Gene ◽  
Cell Types ◽  
Nuclear Gene Expression ◽  
Cytoskeletal Regulation ◽  
Neuronal Gene ◽  
The Impact ◽  
Serum Response

AbstractActin, arranged for example in stress fibres, provides a fundamental cytoskeletal frame­work function to all cell types. Notably, there is now mounting evidence that, in addition to cytoplasmic cytoskeletal regulation, ac­tin treadmilling provides a signal modulat­ing nuclear gene expression. In altering gene regulation, cytoplasmic and most likely also a nucleus-resident actin provides an addition­al (gene) regulatory twist to cell motility. So far, the transcription factor serum response factor (SRF) alongside its myocardin-relat­ed transcription factor (MRTF) cofactors has emerged as the main target of actin dynam­ics. In this review, we discuss the impact of actin signalling on nuclear gene expression in the nervous system, where the actin-MRTF-SRF module contributes to various processes including neuronal motility.

scholarly journals GUN1 regulates tetrapyrrole biosynthesis

2019 ◽  
Author(s):  
Takayuki Shimizu ◽  
Nobuyoshi Mochizuki ◽  
Akira Nagatani ◽  
Satoru Watanabe ◽  
Tomohiro Shimada ◽  
...  
Keyword(s):  
Chloroplast Development ◽  
Photosynthetic Apparatus ◽  
Nuclear Gene ◽  
Retrograde Signaling ◽  
Tetrapyrrole Biosynthesis ◽  
Metal Porphyrins ◽  
Nuclear Gene Expression ◽  
Chloroplast Genomes ◽  
Tetrapyrrole Metabolism

The biogenesis of the photosynthetic apparatus in developing chloroplasts requires the assembly of proteins encoded on both nuclear and chloroplast genomes1. To co-ordinate this process there needs to be communication between these organelles, and while we have a good understanding of how the nucleus controls chloroplast development, how the chloroplast communicates with the nucleus at this time is still essentially unknown2. What we do know comes from pioneering work in which a series of genomes uncoupled (gun) mutants were identified that show elevated nuclear gene expression after chloroplast damage3. Of the six reported gun mutations, five are in tetrapyrrole biosynthesis proteins4-6 and this has led to the development of a model for chloroplast-to-nucleus retrograde signaling in which ferrochelatase 1 (FC1)-dependent heme synthesis generates a positive signal promoting expression of photosynthesis-related genes6. However, the molecular consequences of the strongest of the gun mutants, gun17, is unknown, preventing the development of a unifying hypothesis for chloroplast-to-nucleus signaling. Here, we show that GUN1 directly binds to heme and other metal-porphyrins, affects flux through the tetrapyrrole biosynthesis pathway and can increase the chelatase activity of FC1. These results raise the possibility that the signaling role of GUN1 may be manifested through changes in tetrapyrrole metabolism and supports a role for tetrapyrroles as mediators of a single biogenic chloroplast-to-nucleus retrograde signaling pathway.

Evaluări silvopatologice în arboretele de cvercinee (studiu de caz)

2019 ◽  
Author(s):  
Ala Donica ◽  
◽  
Natalia Raileanu ◽  
Keyword(s):  
Environmental Changes ◽  
Stress Factors ◽  
Healthy Tree ◽  
Effective Strategies ◽  
Crown Defoliation ◽  
The Face ◽  
Abiotic And Biotic Factors ◽  
The Impact ◽  
Erannis Defoliaria

The study aim was to identify the impact of the major defoliator pests of oaks, in correlation with the main oaks phenological phenomena and the development of various pests stages, to better understand the vitality of forest ecosystems, the causes and effects of stress factors. It was determined that the most aggressive pests of oaks in the studied stands were on the leaves: insects of fam.Cynipidae, Totrix viridana, Erannis defoliaria, Operophtera rumata, Tischeria complanella, insects of fam.Argidae; and on the fruit - Balaninus glandium. The actions of the insects were directly dependent on abiotic and biotic factors. The use of pheromone traps has proved to be an effective method in monitoring the pests of the investigated stands and has allowed the determination of outbreaks for the development of sp.Totrix viridana and Lymantria dispar. During the growing season, through crown defoliation, trees have gone from healthy tree to moderate and severe ones. The study suggests the need to develop effective strategies and measures to protect forests in the face of environmental changes.

scholarly journals The retrograde signaling protein GUN1 regulates tetrapyrrole biosynthesis

2019 ◽  
Vol 116 (49) ◽  
pp. 24900-24906 ◽  
Author(s):  
Takayuki Shimizu ◽  
Sylwia M. Kacprzak ◽  
Nobuyoshi Mochizuki ◽  
Akira Nagatani ◽  
Satoru Watanabe ◽  
...  
Keyword(s):  
Photosynthetic Apparatus ◽  
Nuclear Gene ◽  
Retrograde Signaling ◽  
Biosynthesis Pathway ◽  
Tetrapyrrole Biosynthesis ◽  
Positive Signal ◽  
Nuclear Gene Expression ◽  
Chloroplast Genomes ◽  
Tetrapyrrole Metabolism

The biogenesis of the photosynthetic apparatus in developing seedlings requires the assembly of proteins encoded on both nuclear and chloroplast genomes. To coordinate this process there needs to be communication between these organelles, but the retrograde signals by which the chloroplast communicates with the nucleus at this time are still essentially unknown. The Arabidopsis thaliana genomes uncoupled (gun) mutants, that show elevated nuclear gene expression after chloroplast damage, have formed the basis of our understanding of retrograde signaling. Of the 6 reported gun mutations, 5 are in tetrapyrrole biosynthesis proteins and this has led to the development of a model for chloroplast-to-nucleus retrograde signaling in which ferrochelatase 1 (FC1)-dependent heme synthesis generates a positive signal promoting expression of photosynthesis-related genes. However, the molecular consequences of the strongest of the gun mutants, gun1, are poorly understood, preventing the development of a unifying hypothesis for chloroplast-to-nucleus signaling. Here, we show that GUN1 directly binds to heme and other porphyrins, reduces flux through the tetrapyrrole biosynthesis pathway to limit heme and protochlorophyllide synthesis, and can increase the chelatase activity of FC1. These results raise the possibility that the signaling role of GUN1 may be manifested through changes in tetrapyrrole metabolism, supporting a role for tetrapyrroles as mediators of a single biogenic chloroplast-to-nucleus retrograde signaling pathway.

Particularities of the independent auditor's report on reliability of accounting (financial) statements for 2019: COVID-19 as qualitatively essential information (Part 2)

2020 ◽  
Vol 23 (7) ◽  
pp. 777-799
Author(s):  
O.I. Shvyreva ◽  
Z.I. Kruglyak ◽  
A.V. Petukh
Keyword(s):  
Financial Reporting ◽  
Financial Statements ◽  
Economic Situation ◽  
Risk Disclosure ◽  
Essential Information ◽  
Logical Method ◽  
Annual Reporting ◽  
The Face ◽  
Key Aspects ◽  
The Impact

Subject. This article discusses the issues related to the practice of financial reporting in the face of uncertainties caused by the coronavirus contagion, as well as the specifics of the audit strategy and formation of an audit opinion on this reporting. Objectives. The article aims to identify the quality characteristics of financial reporting prepared in the context of the COVID-19 pandemic and justify the key aspects of assurance engagement completion in an extremely uncertain epidemiological and economic situation. Methods. For the study, we used an abstract-logical method, content analysis techniques, systematization, and classification. Results. Analyzing the impact of the extremely uncertain epidemiological and economic situation on financial statements, the article clarifies aspects of disclosure of events after the reporting date and threats to business continuity in the annual reporting of economic entities. The article identifies possible alternative procedures and algorithms to obtain proper evidence when it is insufficient in the face of the inability to meet certain audit standards requirements in a remote audit environment. The article defines the impact of COVID-19 risk disclosure on the structure of the audit report and opinion. Relevance. The results of the study can be used in the practical activities of economic entities that prepare financial statements in the face of significant uncertainty, as well as auditors and audit organizations.

Safe development of business and national economy in the face of a pandemic and global recession

2020 ◽  
Vol 16 (6) ◽  
pp. 1182-1198
Author(s):  
I.V. Vyakina
Keyword(s):  
Economic Security ◽  
Global Recession ◽  
Graphical Visualization ◽  
National Economic ◽  
Business Support ◽  
The Face ◽  
The Russian Federation ◽  
Business Entities ◽  
Visualization Techniques ◽  
The Impact

Subject. This article deals with the issues related to the national economic security of the State in today's conditions. Objectives. The article aims to develop a set of special measures for additional business support to reduce the impact of restrictions imposed against the background of quarantine and the pandemic spread, and which would help prevent collapse of business entities. Methods. For the study, I used the methods of theoretical, systems, logical, and comparative analyses, and tabular and graphical visualization techniques. Results. The article proposes possible measures to support business aimed at reducing the costs of business entities due to the restrictions caused by the pandemic, that complement and explain the activities proposed by the President and Government of the Russian Federation, taking into account the regional and municipal levels. Conclusions. The uncertain current situation requires constant adjustment and adaptation of public policy in accordance with specific circumstances. Ensuring the country's economic security and sustainability associates with creation of a business organization system that connects public administration tools and business support and development opportunities under the changed environment.

The Impact of Terrorism on Construction Industry in Iraq

2015 ◽  
Vol 3 (2) ◽  
pp. 69-84
Author(s):  
Wadhah Amer Hatem ◽  
Samiaah M. Hassen Al-Tmeemy
Keyword(s):  
Construction Industry ◽  
Construction Projects ◽  
Historical Data ◽  
Terrorist Attacks ◽  
Construction Sector ◽  
Statistical Procedures ◽  
Qualitative Approaches ◽  
Suicide Attacks ◽  
The Face ◽  
The Impact

     Suicide attacks, bombings, explosions became the part of daily life in Iraq. Consequently, the threat of terrorism put the Iraqi construction sector in the face of unique and unusual challenges that not seen on other countries. These challenges can have extensive impact on construction projects. This paper seeks to examine the impact of the terrorist attacks on construction industry and determine the extent to which the impact of terrorism on construction projects in terms of cost, schedule, and quality. This study adapted quantitative and qualitative approaches to collect data using questionnaire survey and interviews, as well as historical data. The study focused on projects that have been the target of terrorist strikes in Diyala governorate. A variety of statistical procedures were employed in data analysis. The results revealed the extent to which terrorist attacks impact construction projects in terms of cost, time, and quality. The results of this study will enhance the awareness of all construction parties to the impact of the terrorist attacks against construction projects. Eventually, this can develop a risk management assessment and assist contractors to properly protect projects and buildings to minimize injuries and fatalities in the event of terrorism.

Designing a CRM Framework for online & offline sports footwear retailers

2015 ◽  
Vol 3 (1) ◽  
Author(s):  
Rodrigo Cueva ◽  
Guillem Rufian ◽  
Maria Gabriela Valdes
Keyword(s):  
Environmental Changes ◽  
Customer Relationship ◽  
Business Strategies ◽  
Economic Sectors ◽  
Running Shoes ◽  
Brick And Mortar ◽  
Key Factor ◽  
On Line ◽  
The Impact

The use of Customer Relationship Managers to foster customers loyalty has become one of the most common business strategies in the past years.  However, CRM solutions do not fill the abundance of happily ever-after relationships that business needs, and each client’s perception is different in the buying process.  Therefore, the experience must be precise, in order to extend the loyalty period of a customer as much as possible. One of the economic sectors in which CRM’s have improved this experience is retailing, where the personalized attention to the customer is a key factor.  However, brick and mortar experiences are not enough to be aware in how environmental changes could affect the industry trends in the long term.  A base unified theoretical framework must be taken into consideration, in order to develop an adaptable model for constructing or implementing CRMs into companies. Thanks to this approximation, the information is complemented, and the outcome will increment the quality in any Marketing/Sales initiative. The goal of this article is to explore the different factors grouped by three main domains within the impact of service quality, from a consumer’s perspective, in both on-line and off-line retailing sector.  Secondly, we plan to go a step further and extract base guidelines about previous analysis for designing CRM’s solutions focused on the loyalty of the customers for a specific retailing sector and its product: Sports Running Shoes.

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