scholarly journals Determining the inherent reaction-diffusion properties of actin-binding proteins in cells by incorporating genetic engineering to FRAP-based framework

2020 ◽  
Author(s):  
Takumi Saito ◽  
Daiki Matsunaga ◽  
Tsubasa S. Matsui ◽  
Kentaro Noi ◽  
Shinji Deguchi

AbstractProteins in cells undergo repeated association to other molecules, thereby reducing the apparent extent of their intracellular diffusion. While much effort has been made to analytically decouple these combined effects of pure diffusion and chemical reaction, it is difficult to attribute the measured quantities to the nature of specific domains of the probed proteins particularly if, as is often the case, the protein has multiple domains to independently interact with the same types but different molecules. Motivated by the common goal in cell signaling research aimed at identifying the protein domains responsible for particular intermolecular interactions, here we describe a new approach to determining the domain-level reaction and pure diffusion properties. To validate this methodology, we apply it to transgelin-2, an actin-binding protein whose intracellular dynamics remains elusive. We develop a fluorescence recovery after photobleaching (FRAP)-based framework, in which comprehensive combinations of domain-deletion mutants are created with genetic engineering, and the difference among the mutants in FRAP response is analyzed. We demonstrate that transgelin-2 in cells interacts with F-actin via two separate domains, and the chemical equilibrium constant of the interaction is determined at the individual domain levels. Its pure diffusion properties independent of the association to F-actin is also obtained. This approach requires some effort to construct the mutants, but instead enables in situ domain-level determination of the physicochemical properties, which will be useful, as specifically shown here for transgelin-2, in addressing the signaling mechanism of cellular proteins.

2017 ◽  
Vol 49 (2) ◽  
pp. 467-490 ◽  
Author(s):  
Zachary Peskowitz

This article develops a novel explanation for the incumbency advantage based on incumbents’ ability to signal positions that are ideologically distinct from those of their parties. Using voter-level data from the Cooperative Congressional Election Study and controlling for unobserved district heterogeneity, the study finds that voters in US House elections primarily use information about the ideology of candidates’ parties to infer the location of challengers, while they instead rely on information about the individual candidates’ ideologies to place incumbents. In higher-profile Senate elections, the difference between challengers and incumbents is trivial. Decomposing the incumbency advantage into valence and signaling components, the study finds that the signaling mechanism explains 14 per cent of the incumbency advantage in House elections, but only 5 per cent of the advantage in Senate contests. It also finds that a 50 per cent increase in party polarization increases the incumbency advantage by 3 percentage points.


2019 ◽  
Vol 118 (7) ◽  
pp. 101-110
Author(s):  
Ms.U.Sakthi Veeralakshmi ◽  
Dr.G. Venkatesan

This research aims at measuring the service quality in public and private banking sector and identifying its relationship to customer satisfaction and behavioral intention. The study was conducted among 500 bank customers by using revised SERVQUAL instrument with 26 items. Behavioral intention of the customers was measured by using the behavioral intention battery. The researcher has used a seven point likert scaling to measure the expected and perceived service quality (performance) and the behavioral intention of the customer. The instrument was selected as the most reliable device to measure the difference-score conceptualization. It is used to evaluate service gap between expectation and perception of service quality. Modifications are made on the SERVQUAL instrument to make it specific to the Banking sector. Questions were added to the instrument like Seating space for waiting (Tangibility), Parking space in the Bank (Tangibility), Variety of products / schemes available (Tangibility), Banks sincere steps to handling Grievances of the customers (Responsiveness). The findings of the study revealed that the customer’s perception (performance) is lower than expectation of the service quality rendered by banks. Responsiveness and Assurance SQ dimensions were the most important dimensions in service quality scored less SQ gap. The study concluded that the individual service quality dimensions have a positive impact on Overall Satisfaction.


Author(s):  
Irina Mordous

The development of modern civilization attests to its decisive role in the progressive development of institutions. They identified the difference between Western civilization and the rest of the world. Confirmation of the institutional advantages of the West was its early industrialization. The genesis and formation of institutionalism in its ideological and conceptualmethodological orientation occurs as a process alternative to neoclassic in the context of world heterodoxia, which quickly spread in social science. Highlighting institutional education as a separate area of sociocultural activity is determined by the factor of differentiation of institutional theory as a whole. A feature of institutional education is its orientation toward the individual and his/her transformation into a personality. The content of institutional education is revealed through the analysis of the institution, which includes a set of established customs, traditions, ways of thinking, behavioral stereotypes of individuals and social groups. The dynamics of socio-political, economic transformations in Ukraine requires a review of the foundations of national education and determination of the prospects for its development in the 21st century in the context of institutionalism.


Author(s):  
O. M. Reva ◽  
V. V. Kamyshin ◽  
S. P. Borsuk ◽  
V. A. Shulhin ◽  
A. V. Nevynitsyn

The negative and persistent impact of the human factor on the statistics of aviation accidents and serious incidents makes proactive studies of the attitude of “front line” aviation operators (air traffic controllers, flight crewmembers) to dangerous actions or professional conditions as a key component of the current paradigm of ICAO safety concept. This “attitude” is determined through the indicators of the influence of the human factor on decision-making, which also include the systems of preferences of air traffic controllers on the indicators and characteristics of professional activity, illustrating both the individual perception of potential risks and dangers, and the peculiarities of generalized group thinking that have developed in a particular society. Preference systems are an ordered (ranked) series of n = 21 errors: from the most dangerous to the least dangerous and characterize only the danger preference of one error over another. The degree of this preference is determined only by the difference in the ranks of the errors and does not answer the question of how much time one error is more dangerous in relation to another. The differential method for identifying the comparative danger of errors, as well as the multistep technology for identifying and filtering out marginal opinions were applied. From the initial sample of m = 37 professional air traffic controllers, two subgroups mB=20 and mG=7 people were identified with statisti-cally significant at a high level of significance within the group consistency of opinions a = 1%. Nonpara-metric optimization of the corresponding group preference systems resulted in Kemeny’s medians, in which the related (middle) ranks were missing. Based on these medians, weighted coefficients of error hazards were determined by the mathematical prioritization method. It is substantiated that with the ac-cepted accuracy of calculations, the results obtained at the second iteration of this method are more ac-ceptable. The values of the error hazard coefficients, together with their ranks established in the preference systems, allow a more complete quantitative and qualitative analysis of the attitude of both individual air traffic controllers and their professional groups to hazardous actions or conditions.


1999 ◽  
Vol 17 (11) ◽  
pp. 3603-3611 ◽  
Author(s):  
Dympna Waldron ◽  
Ciaran A. O'Boyle ◽  
Michael Kearney ◽  
Michael Moriarty ◽  
Desmond Carney

PURPOSE: Despite the increasing importance of assessing quality of life (QoL) in patients with advanced cancer, relatively little is known about individual patient's perceptions of the issues contributing to their QoL. The Schedule for the Evaluation of Individual Quality of Life (SEIQoL) and the shorter SEIQoL–Direct Weighting (SEIQoL-DW) assess individualized QoL using a semistructured interview technique. Here we report findings from the first administration of the SEIQoL and SEIQoL-DW to patients with advanced incurable cancer. PATIENTS AND METHODS: QoL was assessed on a single occasion using the SEIQoL and SEIQoL-DW in 80 patients with advanced incurable cancer. RESULTS: All patients were able to complete the SEIQoL-DW, and 78% completed the SEIQoL. Of a possible score of 100, the median QoL global score was as follows: SEIQoL, 61 (range, 24 to 94); SEIQoL-DW, 60.5 (range, 6 to 95). Psychometric data for SEIQoL indicated very high levels of internal consistency (median r = .90) and internal validity (median R2 = 0.88). Patients' judgments of their QoL were unique to the individual. Family concerns were almost universally rated as more important than health, the difference being significant when measured using the SEIQoL-DW (P = .002). CONCLUSION: Patients with advanced incurable cancer were very good judges of their QoL, and many patients rated their QoL as good. Judgments were highly individual, with very high levels of consistency and validity. The primacy given to health in many QoL questionnaires may be questioned in this population. The implications of these findings are discussed with regard to clinical assessment and advance directives.


Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 394
Author(s):  
Cheng-Han Li ◽  
Chun-Hung Hsieh ◽  
Cheng-Chu Hung ◽  
Ching-Wei Cheng

After completing the production of preserved eggs, traditionally, the degree of gelling is judged by allowing workers to tap the preserved eggs with their fingers and sense the resulting oscillations. The amount of oscillation is used for the quality classification. This traditional method produces varying results owing to the differences in the sensitivity of the individual workers, who are not objective. In this study, dielectric detection technology was used to classify the preserved eggs nondestructively. The impedance in the frequency range of 2–300 kHz was resolved into resistance and reactance, and was plotted on a Nyquist diagram. Next, the diagram curve was fitted in order to obtain the equivalent circuit, and the difference in the compositions of the equivalent circuits corresponding to gelled and non-gelled preserved eggs was analyzed. A preserved egg can be considered an RLC series circuit, and its decay rate is consistent with the decay rate given by mechanical vibration theory. The Nyquist diagrams for the resistance and reactance of preserved eggs clearly showed that the resistance and reactance of gelled and non-gelled eggs were quite different, and the classification of the eggs was performed using Bayesian network (BN). The results showed that a BN classifier with two variables, i.e., resistance and reactance, can be used to classify preserved eggs as gelled or non-gelled, with an accuracy of 81.0% and a kappa value of 0.62. Thus, a BN classifier based on resistance and reactance demonstrates the ability to classify the quality of preserved egg gel. This research provides a nondestructive method for the inspection of the quality of preserved egg gel, and provides a theoretical basis for the development of an automated preserved egg inspection system that can be used as the scientific basis for the determination of the quality of preserved eggs.


Biomolecules ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1038
Author(s):  
Jianyuan Zeng ◽  
Wen G. Jiang ◽  
Andrew J. Sanders

Epithelial Protein Lost In Neoplasm (EPLIN), also known as LIMA1 (LIM Domain And Actin Binding 1), was first discovered as a protein differentially expressed in normal and cancerous cell lines. It is now known to be key to the progression and metastasis of certain solid tumours. Despite a slow pace in understanding the biological role in cells and body systems, as well as its clinical implications in the early years since its discovery, recent years have witnessed a rapid progress in understanding the mechanisms of this protein in cells, diseases and indeed the body. EPLIN has drawn more attention over the past few years with its roles expanding from cell migration and cytoskeletal dynamics, to cell cycle, gene regulation, angiogenesis/lymphangiogenesis and lipid metabolism. This concise review summarises and discusses the recent progress in understanding EPLIN in biological processes and its implications in cancer.


2002 ◽  
Vol 283 (3) ◽  
pp. C850-C865 ◽  
Author(s):  
Caterina Di Ciano ◽  
Zilin Nie ◽  
Katalin Szászi ◽  
Alison Lewis ◽  
Takehito Uruno ◽  
...  

Osmotic stress is known to affect the cytoskeleton; however, this adaptive response has remained poorly characterized, and the underlying signaling pathways are unexplored. Here we show that hypertonicity induces submembranous de novo F-actin assembly concomitant with the peripheral translocation and colocalization of cortactin and the actin-related protein 2/3 (Arp2/3) complex, which are key components of the actin nucleation machinery. Additionally, hyperosmolarity promotes the association of cortactin with Arp2/3 as revealed by coimmunoprecipitation. Using various truncation or phosphorylation-incompetent mutants, we show that cortactin translocation requires the Arp2/3- or the F-actin binding domain, but the process is independent of the shrinkage-induced tyrosine phosphorylation of cortactin. Looking for an alternative signaling mechanism, we found that hypertonicity stimulates Rac and Cdc42. This appears to be a key event in the osmotically triggered cytoskeletal reorganization, because 1) constitutively active small GTPases translocate cortactin, 2) Rac and cortactin colocalize at the periphery of hypertonically challenged cells, and 3) dominant-negative Rac and Cdc42 inhibit the hypertonicity-provoked cortactin and Arp3 translocation. The Rho family-dependent cytoskeleton remodeling may be an important osmoprotective response that reinforces the cell cortex.


2007 ◽  
Vol 18 (3) ◽  
pp. 827-838 ◽  
Author(s):  
Céline Revenu ◽  
Matthieu Courtois ◽  
Alphée Michelot ◽  
Cécile Sykes ◽  
Daniel Louvard ◽  
...  

Villin, an actin-binding protein associated with the actin bundles that support microvilli, bundles, caps, nucleates, and severs actin in a calcium-dependant manner in vitro. We hypothesized that the severing activity of villin is responsible for its reported role in enhancing cell plasticity and motility. To test this hypothesis, we chose a loss of function strategy and introduced mutations in villin based on sequence comparison with CapG. By pyrene-actin assays, we demonstrate that this mutant has a strongly reduced severing activity, whereas nucleation and capping remain unaffected. The bundling activity and the morphogenic effects of villin in cells are also preserved in this mutant. We thus succeeded in dissociating the severing from the three other activities of villin. The contribution of villin severing to actin dynamics is analyzed in vivo through the actin-based movement of the intracellular bacteria Shigella flexneri in cells expressing villin and its severing variant. The severing mutations abolish the gain of velocity induced by villin. To further analyze this effect, we reconstituted an in vitro actin-based bead movement in which the usual capping protein is replaced by either the wild type or the severing mutant of villin. Confirming the in vivo results, villin-severing activity enhances the velocity of beads by more than two-fold and reduces the density of actin in the comets. We propose a model in which, by severing actin filaments and capping their barbed ends, villin increases the concentration of actin monomers available for polymerization, a mechanism that might be paralleled in vivo when an enterocyte undergoes an epithelio-mesenchymal transition.


1997 ◽  
Vol 50 (1) ◽  
pp. 1-38 ◽  
Author(s):  
Iain Provan

It is well known that the seeds from which the modern discipline of OT theology grew are already found in 17th and 18th century discussion of the relationship between Bible and Church, which tended to drive a wedge between the two, regarding canon in historical rather than theological terms; stressing the difference between what is transient and particular in the Bible and what is universal and of abiding significance; and placing the task of deciding which is which upon the shoulders of the individual reader rather than upon the church. Free investigation of the Bible, unfettered by church tradition and theology, was to be the way ahead. OT theology finds its roots more particularly in the 18th century discussion of the nature of and the relationship between Biblical Theology and Dogmatic Theology, and in particular in Gabler's classic theoreticalstatementof their nature and relationship. The first book which may strictly be called an OT theology appeared in 1796: an historical discussion of the ideas to be found in the OT, with an emphasis on their probable origin and the stages through which Hebrew religious thought had passed, compared and contrasted with the beliefs of other ancient peoples, and evaluated from the point of view of rationalistic religion. Here we find the unreserved acceptance of Gabler's principle that OT theology must in the first instance be a descriptive and historical discipline, freed from dogmatic constraints and resistant to the premature merging of OT and NT — a principle which in the succeeding century was accepted by writers across the whole theological spectrum, including those of orthodox and conservative inclination.


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