scholarly journals Short, Rich, and Powerful: a New Family of Arginine-Rich Small Proteins Have Outsized Impact in Agrobacterium tumefaciens

2020 ◽  
Vol 202 (22) ◽  
Author(s):  
Melene A. Alakavuklar ◽  
Clay Fuqua
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Comprehensive Analysis ◽  
Large Impact ◽  
Content Type ◽  
Sequence Complexity ◽  
New Family ◽  
Small Proteins ◽  
Complex Regulation ◽  
And Behavior ◽  
Limited Sequence

ABSTRACT Due to minute size and limited sequence complexity, small proteins can be challenging to identify but are emerging as important regulators of diverse processes in bacteria. In this issue of the Journal of Bacteriology, Kraus and coworkers (A. Kraus, M. Weskamp, J. Zierles, M. Balzer, et al., J Bacteriol 202:e00309-20, 2020, https://doi.org/10.1128/JB.00309-20) report a comprehensive analysis of a fascinating subfamily of arginine-rich small proteins in Agrobacterium tumefaciens, conserved among Alphaproteobacteria. Their findings reveal that these small proteins are under complex regulation and have a disproportionately large impact on metabolism and behavior.

scholarly journals Arginine-Rich Small Proteins with a Domain of Unknown Function, DUF1127, Play a Role in Phosphate and Carbon Metabolism of Agrobacterium tumefaciens

2020 ◽  
Vol 202 (22) ◽  
Author(s):  
Alexander Kraus ◽  
Mareen Weskamp ◽  
Jennifer Zierles ◽  
Miriam Balzer ◽  
Ramona Busch ◽  
...  
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Carbon Metabolism ◽  
Unknown Function ◽  
Biofilm Formation ◽  
Nutrient Acquisition ◽  
Protein Profiling ◽  
Cell Physiology ◽  
Content Type ◽  
Small Proteins ◽  
Domain Of Unknown Function

ABSTRACT In any given organism, approximately one-third of all proteins have a yet-unknown function. A widely distributed domain of unknown function is DUF1127. Approximately 17,000 proteins with such an arginine-rich domain are found in 4,000 bacteria. Most of them are single-domain proteins, and a large fraction qualifies as small proteins with fewer than 50 amino acids. We systematically identified and characterized the seven DUF1127 members of the plant pathogen Agrobacterium tumefaciens. They all give rise to authentic proteins and are differentially expressed as shown at the RNA and protein levels. The seven proteins fall into two subclasses on the basis of their length, sequence, and reciprocal regulation by the LysR-type transcription factor LsrB. The absence of all three short DUF1127 proteins caused a striking phenotype in later growth phases and increased cell aggregation and biofilm formation. Protein profiling and transcriptome sequencing (RNA-seq) analysis of the wild type and triple mutant revealed a large number of differentially regulated genes in late exponential and stationary growth. The most affected genes are involved in phosphate uptake, glycine/serine homeostasis, and nitrate respiration. The results suggest a redundant function of the small DUF1127 paralogs in nutrient acquisition and central carbon metabolism of A. tumefaciens. They may be required for diauxic switching between carbon sources when sugar from the medium is depleted. We end by discussing how DUF1127 might confer such a global impact on cell physiology and gene expression. IMPORTANCE Despite being prevalent in numerous ecologically and clinically relevant bacterial species, the biological role of proteins with a domain of unknown function, DUF1127, is unclear. Experimental models are needed to approach their elusive function. We used the phytopathogen Agrobacterium tumefaciens, a natural genetic engineer that causes crown gall disease, and focused on its three small DUF1127 proteins. They have redundant and pervasive roles in nutrient acquisition, cellular metabolism, and biofilm formation. The study shows that small proteins have important previously missed biological functions. How small basic proteins can have such a broad impact is a fascinating prospect of future research.

Risk perception and awareness of earthquake: the case of Dhaka

2019 ◽  
Vol 10 (1) ◽  
pp. 65-82 ◽  
Author(s):  
Mohammad Lutfur Rahman
Keyword(s):  
Risk Perception ◽  
Data Collection ◽  
Seismic Risk ◽  
Public Awareness ◽  
Content Type ◽  
Earthquake Preparedness ◽  
Level Of Knowledge ◽  
Seismic Risk Perception ◽  
The Many ◽  
And Behavior

Purpose Among the many studies about risk perception, only a few deal with Bangladesh. Paul and Bhuiyan’s (2010) study has shown the earthquake-preparedness level of residents of Dhaka, but there are some biases in the data collection. This paper aims to examine the seismic-risk perception and the level of knowledge on earthquake and preparedness among the residents of Dhaka. Design/methodology/approach A questionnaire was developed, and data collection was undertaken through home and sidewalk surveys. This paper investigates how attitude, perception and behavior differ depending on gender, age, education and casualty awareness. This research tries to examine and make a comparison of the risk perception and preparedness level between different groups of gender, age and level of education. Findings This research shows that female respondents have a much better risk perception of and are better prepared for earthquakes than male respondents; younger people have a higher knowledge about earthquake preparedness than older people and less-educated people are at a higher risk of unpreparedness than more-educated people. Research limitations/implications This research is only limited to the Dhaka Division. Originality/value This paper concludes by noting that public awareness on seismic-risk perception and mitigation is poor, and their knowledge on basic theory and emergency response must be improved.

scholarly journals Melanization in Cryptococcus neoformans Requires Complex Regulation

mBio ◽  
2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Radames J. B. Cordero ◽  
Emma Camacho ◽  
Arturo Casadevall
Keyword(s):  
Cryptococcus Neoformans ◽  
Defense Mechanisms ◽  
Environmental Stressors ◽  
Antimicrobial Compounds ◽  
Human Pathogen ◽  
Content Type ◽  
Signaling Mechanisms ◽  
Complex Regulation ◽  
Multiple Levels ◽  
Melanin Binding

ABSTRACT The fungal human pathogen Cryptococcus neoformans undergoes melanization in response to nutrient starvation and exposure to exogenous melanin precursors. Melanization protects the fungus against host defense mechanisms such as oxidative damage and other environmental stressors (e.g., heat/cold stress, antimicrobial compounds, ionizing radiation). Conversely, the melanization process generates cytotoxic intermediates, and melanized cells are potentially susceptible to overheating and to certain melanin-binding drugs. Despite the importance of melanin in C. neoformans biology, the signaling mechanisms regulating its synthesis are poorly understood. The recent report by D. Lee, E.-H. Jang, M. Lee, S.-W. Kim, et al. [mBio 10(5):e02267-19, 2019, https://doi.org/10.1128/mBio.02267-19] provides new insights into how C. neoformans regulates melanization. The authors identified a core melanin regulatory network consisting of transcription factors and kinases required for melanization under low-nutrient conditions. The redundant and epistatic connections of this melanin-regulating network demonstrate that C. neoformans melanization is complex and carefully regulated at multiple levels. Such complex regulation reflects the multiple functions of melanin in C. neoformans biology.

It’s just not fair: exploring the effects of firm customization on unfairness perceptions, trust and loyalty

2014 ◽  
Vol 28 (6) ◽  
pp. 484-497 ◽  
Author(s):  
Bang Nguyen ◽  
Philipp “Phil” Klaus ◽  
Lyndon Simkin
Keyword(s):  
Conceptual Model ◽  
Customer Loyalty ◽  
Linear Regression Analysis ◽  
Perceived Fairness ◽  
Content Type ◽  
Negative Perceptions ◽  
Loyalty Intentions ◽  
And Behavior ◽  
Development And Validation

Purpose – The purpose of this study is to (a) develop a conceptual framework exploring the relationships between perceived negative firm customization, unfairness perceptions, and customer loyalty intentions, and (b) investigate the moderating effects of trust in these relationships. The study explores how customizing offers to match customers’ individual needs and how treating customers differentially provoke unfairness perceptions among those not being considered most important. While the literature discusses unfairness perceptions of pricing, promotion, and service, less is known about unfairness in customization practices. Design/methodology/approach – Using a survey approach, 443 completed questionnaires we collected. Following validation of our item measures, a hierarchical linear regression analysis was conducted to test the conceptual model and hypothesized linkages between our constructs. Findings – The results demonstrate that customers’ negative perceptions of customization increase their unfairness perceptions. Unfairness perceptions drastically reduce customer loyalty intentions with trust acting as a significant moderator. Trust increases loyalty intentions even when unfairness perceptions are present. Our findings provide a foundation for understanding how firms may improve their perceived fairness. This increase in perceived fairness creates positive attributions, reduces negative customer experience perceptions and increases loyalty intentions. Originality/value – Key contribution is the development and validation of a conceptual model explaining the linkages between firm customization and unfairness perceptions, firm customization and customer loyalty intentions and the moderating role of trust between these relationships. This study extends the understanding of how customization practices impact unfairness perceptions and, subsequently, influence consumers’ perceptions, intentions and behavior.

Cultural differences in gift recipients’ attitude and behavior toward disliked gifts

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Theeranuch Pusaksrikit ◽  
Sydney Chinchanachokchai
Keyword(s):  
Cultural Differences ◽  
Future Research ◽  
Content Type ◽  
Relationship Closeness ◽  
Marketing Segmentation ◽  
Self Construal ◽  
The Usa ◽  
And Behavior ◽  
Different Cultures ◽  
The Relationship

Purpose The purpose of this paper is to examine the effects of cultural differences and the types of relationship closeness involved in recipients’ emotional and behavioral reactions after receiving disliked gifts. Design/methodology/approach Collecting data from Thailand and the USA, two experiments were conducted in a 2 (self-construal: independent/interdependent) × 2 (relationship closeness: close/distant) between-subjects design. Study 1 explores the recipients’ feelings and reactions upon receipt of a disliked gift. Study 2 explores the disposition process for a disliked gift. Findings The results show that a recipient’s emotions, reaction and disposition process can be affected by cultural differences and relationship closeness: specifically that close and distant relationships moderate the relationship between self-construal and gift-receiving attitudes and behaviors. Research limitations/implications Future research can investigate representative groups from other countries to broaden the generalizability of the findings. Practical implications This understanding can guide gift-givers when selecting gifts for close or distant recipients across cultures. Additionally, it can help retailers develop and introduce new marketing strategies by applying self-construal as a marketing segmentation tool for gift purchase and disposition. Originality/value This research is among the first studies to offer insights into how individuals in different cultures manage disliked gifts they receive from people in either close or distant relationships.

Authentic leadership and follower’s role ethnicality: the role of leader’s ethical voice and ethical culture

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Muhammad Asim Faheem ◽  
Ishfaq Ahmed ◽  
Insya Ain ◽  
Zanaira Iqbal
Keyword(s):  
Authentic Leadership ◽  
Ethical Issues ◽  
Survey Design ◽  
Moderated Mediation ◽  
Ethical Culture ◽  
Content Type ◽  
Work Demand ◽  
The Past ◽  
And Behavior

Purpose The ethical issues arising at work demand the role of both leader and employees, but how both the levels are linked in determining the ethical responses is an area that has not gained due attention in the past. Against this backdrop, this study aims to address the influence of a leader’s authenticity and ethical voice on ethical culture and the role ethicality of followers. Design/methodology/approach Survey design has been used, and a questionnaire is used to elicit the responses. In total, 381 filled questionnaires were used for data analysis. Findings The findings of this study highlight the role of authentic leadership in predicting the role ethicality of followers both directly and through the mediation of ethical culture. Furthermore, a leader’s ethical voice strengthens the authentic leadership and outcome relationships (with ethical culture and followers’ role ethicality). The moderated-mediation mechanism has proved as the leaders’ voice foster the indirect mechanism. Originality/value There is a dearth of literature that has focused on leadership traits (authenticity) and behavior (ethical voice) in predicting the followers’ outcomes (perceptions – ethical culture and behaviors – role ethicality). The moderated-mediation mechanism has been unattended in the past.

Digging deep? Digging more? A research on the influence of corporate CSR theme consistency strategy

2018 ◽  
Vol 1 (1) ◽  
pp. 76-93 ◽  
Author(s):  
Yang Zhang ◽  
Xuhui Wang ◽  
Yingying Shen
Keyword(s):  
Communication Channel ◽  
Information Dissemination ◽  
Focal Point ◽  
Social Programs ◽  
Business Practices ◽  
Content Type ◽  
Moderation Effect ◽  
Corporate Social ◽  
And Behavior ◽  
Selection Of

PurposeAs the focal point of both academic studies and business practices, the theme strategy of corporate social responsibility (CSR) arouses wide attention. However, extant studies concentrate more on the selection of the theme of CSR activities, such as the fitness between CSR activities and the core business, thus largely neglecting the consistency of the theme. The purpose of this paper is to determine whether the enterprise should adopt a consistent theme strategy or should participate in different social programs, and how do customers response to the lack of studies in different theme-consistent strategies.Design/methodology/approachIn this paper, two progressive experiments are performed. The purpose of study 1 is to examine the influence of theme consistency on consumers’ CSR association and how consumers’ attribution to corporation motivation mediates such impacts. The purpose for study 2 is to examine whether information dissemination channels and cooperation with public organization could affect the influence of theme consistency strategy.FindingsThe significant influences of theme consistency on consumer CSR association was demonstrated, and consumer’s perceived motivation of CSR was found to play the mediation role. Moreover, the moderation effect of the communication channel of CSR information was found to be important to strengthen the influence of the theme-consistent strategy.Originality/valueThis paper not only demonstrates the influence of theme consistency, but also explains how theme consistency influences consumers’ attitude and behavior. It enriches the study on the antecedent variables of consumers’ attribution to corporate motivation.

scholarly journals New Players in the Toxin Field: Polymorphic Toxin Systems in Bacteria

mBio ◽  
2015 ◽  
Vol 6 (3) ◽  
Author(s):  
Anne Jamet ◽  
Xavier Nassif
Keyword(s):  
In Silico ◽  
Bacterial Strains ◽  
Secretion Systems ◽  
Toxic Activity ◽  
New Family ◽  
Small Proteins ◽  
Immunity Genes ◽  
Dependent Growth ◽  
Contact Dependent Growth Inhibition ◽  
Terminal Domains

ABSTRACTBacteria have evolved numerous strategies to increase their competitiveness and fight against each other. Indeed, a large arsenal of antibacterial weapons is available in order to inhibit the proliferation of competitor cells. Polymorphic toxin systems (PTS), recently identified by bioinformatics in all major bacterial lineages, correspond to such a system primarily involved in conflict between related bacterial strains. They are typically composed of a secreted multidomain toxin, a protective immunity protein, and multiple cassettes encoding alternative toxic domains. The C-terminal domains of polymorphic toxins carry the toxic activity, whereas the N-terminal domains are related to the trafficking mode.In silicoanalysis of PTS identified over 150 distinct toxin domains, including putative nuclease, deaminase, or peptidase domains. Immunity genes found immediately downstream of the toxin genes encode small proteins that protect bacteria against their own toxins or against toxins secreted by neighboring cells. PTS encompass well-known colicins and pyocins, contact-dependent growth inhibition systems which include CdiA and Rhs toxins and some effectors of type VI secretion systems. We have recently characterized the MafB toxins, a new family of PTS deployed by pathogenicNeisseriaspp. Many other putative PTS have been identified byin silicopredictions but have yet to be characterized experimentally. However, the high number of these systems suggests that PTS have a fundamental role in bacterial biology that is likely to extend beyond interbacterial competition.

scholarly journals Loss of PodJ in Agrobacterium tumefaciens Leads to Ectopic Polar Growth, Branching, and Reduced Cell Division

2016 ◽  
Vol 198 (13) ◽  
pp. 1883-1891 ◽  
Author(s):  
James C. Anderson-Furgeson ◽  
John R. Zupan ◽  
Romain Grangeon ◽  
Patricia C. Zambryski
Keyword(s):  
Cell Cycle ◽  
Cell Division ◽  
Agrobacterium Tumefaciens ◽  
Cell Envelope ◽  
Critical Factor ◽  
Polar Growth ◽  
Content Type ◽  
Growth Pole ◽  
Envelope Material ◽  
Z Ring

ABSTRACTAgrobacterium tumefaciensis a rod-shaped Gram-negative bacterium that elongates by unipolar addition of new cell envelope material. Approaching cell division, the growth pole transitions to a nongrowing old pole, and the division site creates new growth poles in sibling cells. TheA. tumefacienshomolog of theCaulobacter crescentuspolar organizing protein PopZ localizes specifically to growth poles. In contrast, theA. tumefacienshomolog of theC. crescentuspolar organelle development protein PodJ localizes to the old pole early in the cell cycle and accumulates at the growth pole as the cell cycle proceeds. FtsA and FtsZ also localize to the growth pole for most of the cell cycle prior to Z-ring formation. To further characterize the function of polar localizing proteins, we created a deletion ofA. tumefacienspodJ(podJAt). ΔpodJAtcells display ectopic growth poles (branching), growth poles that fail to transition to an old pole, and elongated cells that fail to divide. In ΔpodJAtcells,A. tumefaciensPopZ-green fluorescent protein (PopZAt-GFP) persists at nontransitioning growth poles postdivision and also localizes to ectopic growth poles, as expected for a growth-pole-specific factor. Even though GFP-PodJAtdoes not localize to the midcell in the wild type, deletion ofpodJAtimpacts localization, stability, and function of Z-rings as assayed by localization of FtsA-GFP and FtsZ-GFP. Z-ring defects are further evidenced by minicell production. Together, these data indicate that PodJAtis a critical factor for polar growth and that ΔpodJAtcells display a cell division phenotype, likely because the growth pole cannot transition to an old pole.IMPORTANCEHow rod-shaped prokaryotes develop and maintain shape is complicated by the fact that at least two distinct species-specific growth modes exist: uniform sidewall insertion of cell envelope material, characterized in model organisms such asEscherichia coli, and unipolar growth, which occurs in several alphaproteobacteria, includingAgrobacterium tumefaciens. Essential components for unipolar growth are largely uncharacterized, and the mechanism constraining growth to one pole of a wild-type cell is unknown. Here, we report that the deletion of a polar development gene,podJAt, results in cells exhibiting ectopic polar growth, including multiple growth poles and aberrant localization of cell division and polar growth-associated proteins. These data suggest that PodJAtis a critical factor in normal polar growth and impacts cell division inA. tumefaciens.

The identity-based explanation of affective commitment

2014 ◽  
Vol 29 (3) ◽  
pp. 321-340 ◽  
Author(s):  
Long W. Lam ◽  
Yan Liu
Keyword(s):  
Job Performance ◽  
Hierarchical Linear Modeling ◽  
Organizational Identification ◽  
Turnover Intention ◽  
Affective Commitment ◽  
Central China ◽  
Content Type ◽  
Organizational Attachment ◽  
And Behavior ◽  
The Relationship

Purpose – Drawing on social identity and self-categorization theories and building on Meyer and Herscovitch's (2001) work on affective commitment, this study aimed to examine the relationship between organizational identification and affective commitment, and the relationships between these two variables and employees' attitude and behavior. Design/methodology/approach – Data were collected on-site from 158 automobile dealership employees in central China. Regression analysis and hierarchical linear modeling were used to analyze the survey data. Findings – Organizational identification was positively related to affective commitment. Affective commitment was negatively related to turnover intention and positively related to job performance. Affective commitment mediated the relationship between organizational identification and turnover intention, but did not mediate the relationship between organizational identification and job performance. Research limitations/implications – This study contributes to the literature by integrating organizational identification and affective commitment, the two distinct types of employees' organizational attachment. However, results should be cautioned with the limitations of the study. Practical implications – Managers can use employees' organizational identification to foster affective commitment since it leads to a variety of positive work attitudes and behavior. Social implications – Society as a whole may benefit by having more loyal and committed workforce in organisations. Originality/value – This study develops a model that aligns employee commitment and identification. Doing so answers the call for more efforts to integrate the two forms of organizational attachment in order to make more progress in this line of research.

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