Search

Background: Sarajevo Canton in the Federation of Bosnia and Herzegovina has recorded several waves of high SARS‐CoV‐2 transmission and has struggled to reach adequate vaccination coverage. We describe the evolution of infection‐ and vaccine‐induced SARS‐CoV‐2 antibody response and persistence. Methods: We conducted repeated cross‐sectional analyses of blood donors aged 18–65 years in Sarajevo Canton in November–December 2020 and 2021. We analyzed serum samples for anti‐nucleocapsid (anti‐N) and anti‐spike (anti‐S) antibodies. To assess immune durability, we conducted longitudinal analyses of seropositive participants at 6 and 12 months. Results: One thousand fifteen participants were included in Phase 1 (November–December 2020) and 1152 in Phase 2 (November–December 2021). Seroprevalence increased significantly from 19.2% (95% CI: 17.2%–21.4%) in Phase 1 to 91.6% (95% CI: 89.8%–93.1%) in Phase 2. Anti‐S IgG titers were significantly higher among vaccinated (58.5%) than unvaccinated infected participants across vaccine products (p < 0.001), though highest among those who received an mRNA vaccine. At 6 months, 78/82 (95.1%) participants maintained anti‐spike seropositivity; at 12 months, 58/58 (100.0%) participants were seropositive, and 33 (56.9%) had completed the primary vaccine series within 6 months. Among 11 unvaccinated participants who were not re‐infected at 12 months, anti‐S IgG declined from median 770.1 (IQR 615.0–1321.7) to 290.8 (IQR 175.7–400.3). Anti‐N IgG antibodies waned earlier, from 35.4% seropositive at 6 months to 24.1% at 12 months. Conclusions: SARS‐CoV‐2 seroprevalence increased significantly over 12 months from end of 2020 to end of 2021. Although individuals with previous infection may have residual protection, COVID‐19 vaccination is vital to strengthening population immunity. [ABSTRACT FROM AUTHOR]

Digital manufacturing technologies offer many opportunities for established companies to innovate. They promote data‐driven gains in operational efficiency and enable the transformation of current business models or the creation of entirely new differentiation opportunities. However, many digital innovation projects in manufacturing fall short of their initial ambitions and result in incremental improvements to an existing manufacturing system, if at all. To understand the reasons for the discrepancy between initial ambitions and achieved outcomes, we conduct a longitudinal qualitative study based on a collaborative research project with eight companies and additional expert interviews. Applying a paradox lens, we identify three tensional knots that reveal interrelated, multiple tensions of digital innovation management projects in established manufacturing firms: (1) amalgamating physical and digital assets, (2) innovating in an existing modus operandi, and (3) integrating internal and external stakeholders. These tensions result in the simultaneous occurrence of dynamic and conflicting forces that turn digital innovation projects in manufacturing away from their high initial ambitions. Our findings explain why digitizing the manufacturing system is a non‐trivial endeavor for established firms, which need to balance the complexities inherent in digitization efforts and manage conflicting goals. For managers, the findings provide ways to manage the interrelated tensions in their digital innovation efforts, enabling them to better capitalize on disruptive innovation ambitions. [ABSTRACT FROM AUTHOR]

The use of transformer‐based language models in artificial intelligence (AI) has increased adoption in various industries and led to significant productivity advancements in business operations. This article explores how these models can be used to augment human innovation teams in the new product development process, allowing for larger problem and solution spaces to be explored and ultimately leading to higher innovation performance. The article proposes the use of the AI‐augmented double diamond framework to structure the exploration of how these models can assist in new product development (NPD) tasks, such as text summarization, sentiment analysis, and idea generation. It also discusses the limitations of the technology and the potential impact of AI on established practices in NPD. The article establishes a research agenda for exploring the use of language models in this area and the role of humans in hybrid innovation teams. (Note: Following the idea of this article, GPT‐3 alone generated this abstract. Only minor formatting edits were performed by humans.) [ABSTRACT FROM AUTHOR]

Objective: Quality of life (QOL) and quality of care (QOC) in systemic lupus erythematosus (SLE) remains poor. Satisfaction with care (SC), a QOC surrogate, correlates with health behaviors and outcomes. This study aimed to determine correlates of SC in SLE. Methods: A total of 1262 patients with SLE were recruited from various countries. Demographics, disease activity (modified Systemic Lupus Erythematosus Disease Activity Index for the Safety of Estrogens in Lupus Erythematosus: National Assessment trial [SELENA‐SLEDAI]), and QOL (LupusPRO version 1.7) were collected. SC was collected using LupusPRO version 1.7. Regression analyses were conducted using demographic, disease (duration, disease activity, damage, and medications), geographic (eg, China vs United States), and QOL factors as independent predictors. Results: The mean (SD) age was 41.7 (13.5) years; 93% of patients were women. On the univariate analysis, age, ethnicity, current steroid use, disease activity, and QOL (social support, coping) were associated with SC. On the multivariate analysis, Asian participants had worse SC, whereas African American and Hispanic patients had better SC. Greater disease activity, better coping, and social support remained independent correlates of better SC. Compared with US patients, patients from China and Canada had worse SC on the univariate analysis. In the multivariate models, Asian ethnicity remained independently associated with worse SC, even after we adjusted for geographic background (China). No associations between African American or Hispanic ethnicity and SC were retained when geographic location (Canada) was added to the multivariate model. Canadian patients had worse SC when compared with US patients. Higher disease activity, better social support, and coping remained associated with better SC. Conclusion: Greater social support, coping, and, paradoxically, SLE disease activity are associated with better SC. Social support and coping are modifiable factors that should be addressed by the provider, especially in the Asian population. Therefore, evaluation of a patient's external and internal resources using a biopsychosocial model is recommended. Higher disease activity correlated with better SC, suggesting that the latter may not be a good surrogate for QOC or health outcomes. [ABSTRACT FROM AUTHOR]

Objective: Systemic lupus erythematosus (SLE) predominantly affects women. Clinical phenotype and outcomes in SLE may vary by sex and are further complicated by unique concerns that are dependent upon sex-defined roles. We aimed to describe sex differences in disease-specific quality of life (QoL) assessment scores using the Lupus Patient-Reported Outcome (LupusPRO) tool in a large international study.Methods: Cross-sectional data from 1,803 patients with SLE on demographics, self-identified sex status, LupusPRO, and disease activity were analyzed. The LupusPRO tool has 2 constructs: health-related QoL (HRQoL) and non-HRQoL. Disease activity and damage were evaluated using the Safety of Estrogens in Lupus Erythematosus National Assessment version of the Systemic Lupus Erythematosus Disease Activity Index and the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index, respectively. Nonparametric tests were used to compare QoL and disease activity by sex.Results: A total of 122 men and 1,681 women with SLE participated. The mean age was similar by sex, but the damage scores were greater among men. Men fared worse on the non-HRQoL social support domain than women (P = 0.02). When comparing disease and QoL among men and women ages ≤45 years, men were found to have greater damage and worse social support than women. However, women fared significantly worse on lupus symptoms, cognition, and procreation domains with trends for worse functioning on physical health and pain-vitality domains.Conclusion: In the largest study of a diverse group of SLE patients, utilizing a disease-specific QoL tool, sex differences in QoL were observed on both HRQoL and non-HRQoL constructs. Although men performed worse in the social support domain, women (especially those in the reproductive age group) fared worse in other domains. These observations may assist physicians in appropriately addressing QoL issues in a sex-focused manner. [ABSTRACT FROM AUTHOR]

Aim: Our aim was to compare the presence of various common viruses (rhinovirus, enterovirus, adenovirus, Epstein-Barr virus, cytomegalovirus, norovirus, parechovirus) in stool and nasal swab samples as well as virus-specific antibodies in serum samples between children who developed coeliac disease and controls.Methods: A case-control study was established based on the DIABIMMUNE Study cohorts. During the study, eight Estonian children and 21 Finnish children aged 1.5 years to five years developed coeliac disease and each was matched with a disease-free control. Nasal swabs and stool samples were taken at the age of three to six months and the serum samples at the time of diagnosis.Results: Rhinovirus ribonucleic acid was detected in the nasal swabs from five coeliac disease children, but none of the control children (p = 0.05). There were no statistically significant differences in the level of viral antibodies between cases and controls. Enterovirus immunoglobulin G class antibodies were found more frequently in the Estonian than in the Finnish children (63% versus 23%, p = 0.02).Conclusion: This study did not find any marked overall differences in laboratory-confirmed common viral infections between the children who developed coeliac disease and the controls. However, rhinovirus infections were detected slightly more often in those patients who developed coeliac disease. [ABSTRACT FROM AUTHOR]

The single-side Al-centred tris-functionalized hybrid organic-inorganic Anderson polyoxomolybdates (C16H36N)3[Al(OH)3Mo6O18(OCH2)3CNH(C10H8 O)]·C9H7- N·4CH3OH·5H2O (AlMo6-NH-Cin; Cin is cinnamic acid, C10H9O2) and (C16H36N)3[Al(OH)3Mo6O18 (OCH2)3CNH(C19H15ClNO3)]·9H2O (AlMo6-NHIndo; Indo is indometacin, C19H16ClNO4) have been prepared in a mild threestep synthesis and structurally characterized by single-crystal X-ray diffraction, 1H NMRand IR spectroscopies and elemental analysis. Both AlMo6-NH-Cin and AlMo6-NH-Indo crystallize in the orthorhombic space group Pbca. The antibacterial activities of AlMo6-NH-Cin and AlMo6-NH-Indo against the Gram-negative human mucosal pathogen Moraxella catarrhalis were investigated by determination of the minimum inhibitory concentration, which is 32 mg ml-1 for AlMo6-NH-Cin and 256 μg ml-1 for AlMo6-NH-Indo. [ABSTRACT FROM AUTHOR]

The use of thin glass in the field of electrical engineering for screens of mobile phones or laptops is well known and the necessary material requirements such the scratch resistance has been sufficiently researched. For applications in the building sector, however, the determination of the bending tensile strength of such thin glass necessary for structural design represents a new research topic. The test scenarios described in the standard series EN 1288 relevant for the determination of the bending tensile strength, such as the ring‐on‐ring test or the four‐point‐bending test, are not applicable for glass with a thickness of less than 3 mm. One reason is e.g. the high flexibility of the glass in case of four‐point‐bending tests. As a consequence, these test scenarios have to be adapted or new test scenarios have to be developed. The double‐ring bending tensile test was adapted in that the loading ring, e.g. was replaced by a pressure pad of soft elastomer. Thus, a constant stress distribution in the area under the pressure pad necessary for the determination of the probability of failure could be achieved. The four‐point‐bending test was replaced by test set‐ups in which the force is introduced in‐plane – parallel to the glass surface – as a membrane force in the glass and the glass is thereby deformed or bent until breakage analogous to a stability test. Another variant is bending with a constant bending radius. In this test set‐up, a circular arc is created by precise adjustment of the distance of the supported smaller straight edges and their rotation. Thus, the length of the edge, at which sets a constant bending moment can be increased. These alternative test scenarios were theoretically developed and analysed or partially experimentally investigated by means of test series. These experimental series serve to validate the theoretical development of suitable experimental scenarios and are intended to provide a first approach for a necessary adaptation of EN 1288. [ABSTRACT FROM AUTHOR]

Rotavirus (RV) is the leading cause of severe gastroenteritis (GE) in young children, but RVGE has drastically been reduced with the introduction of live oral RV vaccines into childhood immunization program in many countries. Serum IgA antibody is a marker of clinical protection against severe RVGE after RV infection and vaccination. This study investigated VP6-specificity of anti-RV IgA antibody levels in Finnish children aged 6-23 months before and after introduction of RotaTeq® into national immunization program. Although RV inner capsid protein VP6 is considered as antigenic target in clinical and seroepidemiological studies, at present VP6 protein is not commonly employed as a primary ELISA-antigen. Thus, sera from 20 unvaccinated and 19 vaccinated children were examined in ELISA with recombinant VP6 (rVP6) protein, and the VP6-specific responses were compared to responses observed with human RV Wa and bovine RV WC3 cell culture antigens. Moreover, fecal antibodies were tested with rVP6 and Wa cell culture antigen. Equal levels of serum anti-RV IgA antibodies were detected by the three antigens. Fecal IgA titers against rVP6 and Wa antigen showed a correlation with the corresponding serum levels. The results suggest that the IgA response measured by virus-capture ELISA is mainly directed to VP6 protein, supporting the usage of rVP6 in detection of anti-RV IgA antibodies. Natural RV infections and vaccinations induced similar levels of serum VP6-specific IgA antibodies. Serum IgA antibodies after RotaTeq® vaccination showed sustained levels up to two years of age in line with long term protection. J. Med. Virol. 89:239-245, 2017. © 2016 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Humic substances (HS) are important iron chelators responsible for the transport of iron from freshwater systems to the open sea, where iron is essential for marine organisms. Evidence suggests that iron complexed to HS comprises the bulk of the iron ligand pool in near-coastal waters and shelf seas. River-derived HS have been investigated to study their transport to, and dwell in oceanic waters. A library of iron model compounds and river-derived Fe-HS samples were probed in a combined X-ray absorption spectroscopy (XAS) and valence-to-core X-ray emission spectroscopy (VtC-XES) study at the Fe K-edge. The analyses performed revealed that iron complexation in HS samples is only dependent on oxygen-containing HS functional groups, such as carboxyl and phenol. The photoreduction mechanism of FeIII-HS in oceanic conditions into bioavailable aquatic FeII forms, highlights the importance of river-derived HS as an iron source for marine organisms. Consequently, such mechanisms are a vital component of the upper-ocean iron biogeochemistry cycle. [ABSTRACT FROM AUTHOR]

Disturbed brain and peripheral serotonin homeostasis is often found in subjects with autism spectrum disorder (ASD). The role of the serotonin receptor 2A (HTR2A) in the regulation of central and peripheral serotonin homeostasis, as well as its altered expression in autistic subjects, have implicated the HTR2A gene as a major candidate for the serotonin disturbance seen in autism. Several studies, yielding so far inconclusive results, have attempted to associate autism with a functional SNP −1438 G/A (rs6311) in the HTR2A promoter region, while possible contribution of epigenetic mechanisms, such as DNA methylation, to HTR2A dysregulation in autism has not yet been investigated. In this study, we compared the mean DNA methylation within the regulatory region of the HTR2A gene between autistic and control subjects. DNA methylation was analysed in peripheral blood leukocytes using bisulfite conversion and sequencing of the HTR2A region containing rs6311 polymorphism. Autistic subjects of rs6311 AG genotype displayed higher mean methylation levels within the analysed region than the corresponding controls ( P < 0.05), while there was no statistically significant difference for AA and GG carriers. Our study provides preliminary evidence for increased HTR2A promoter methylation in leukocytes of a portion of adult autistic subjects, indicating that epigenetic mechanisms might contribute to HTR2A dysregulation observed in individuals with ASD. Autism Res 2016, 9: 204-209. © 2015 International Society for Autism Research, Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Four aromatic hybrid Anderson polyoxomolybdates with Fe3+ or Mn3+ as the central heteroatom have been synthesized by using a pre-functionalization protocol and characterized by using single-crystal X-ray diffraction, FTIR, ESI-MS, 1H NMR spectroscopy, and elemental analysis. Structural analysis revealed the formation of (TBA)3[FeMo6O18{(OCH2)3CNHCOC6H5}2] ⋅3.5 ACN ( TBA-FeMo6-bzn; TBA=tetrabutylammonium, ACN=acetonitrile, bzn=TRIS-benzoic acid alkanolamide, TRISR=(HOCH2)3CR)), (TBA)3[FeMo6O18{(OCH2)3CNHCOC8H7}2] ⋅2.5 ACN ( TBA-FeMo6-cin; cin=TRIS-cinnamic acid alkanolamide), (TBA)3[MnMo6O18{(OCH2)3CNHCOC6H5}2] ⋅3.5 ACN ( TBA-MnMo6-bzn), and (TBA)3[MnMo6O18{(OCH2)3CNHCOC8H7}2] ⋅2.5 ACN ( TBA-MnMo6-cin). To make these four compounds applicable in biological systems, an ion exchange was performed that gave the water-soluble (up to 80 m M) sodium salts Na3[FeMo6O18{(OCH2)3CNHCOC6H5}2] ( Na-FeMo6-bzn), Na3[FeMo6O18{(OCH2)3CNHCOC8H7}2] ( Na-FeMo6-cin), Na3[MnMo6O18{(OCH2)3CNHCOC6H5}2] ( Na-MnMo6-bzn), and Na3[MnMo6O18{(OCH2)3CNHCOC8H7}2] ( Na-MnMo6-cin). The hydrolytic stability of the sodium salts was examined by applying ESI-MS in the pH range of 4 to 9. Sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that human and bovine serum albumin (HSA and BSA) remain intact in solutions that contain up to 100 equivalents of the sodium salts over more than 4 d at 20 °C. Tryptophan (Trp) fluorescence quenching was applied to study the interactions between the sodium salts and HSA and BSA at pH 5.5 and 7.4. The quenching constants were extracted by using Stern-Volmer analysis, which suggested the formation of a 1:1 POM-protein complex in all samples. It is suggested that the aromatic hybrid POM approaches subdomain IIA of HSA and exhibits hydrophobic interactions with its hydrophobic tails, whereas the Anderson core is stabilized through electrostatic interactions with polar amino acid side chains from, for example, subdomain IB. [ABSTRACT FROM AUTHOR]

Noroviruses (NoVs) are major causative agents of acute gastroenteritis (AGE) in children worldwide and the most common viral cause of AGE in countries where rotavirus incidence has been eliminated by vaccination. Previous infections with the dominant GII.4 NoV genotype confer only partial protection against evolving immune escape variants that emerge every few years. The objective of this work was to investigate GII.4-specific homologous and cross-reactive antibody responses in young children after NoV GII.4-2009 New Orleans (NO) infection. Virus-like particles (VLPs) representing GII.4-1999, GII.4-2009 NO, and GII.4-2012 Sydney genotypes were used in ELISA and histo-blood group antigen blocking assays to examine acute and convalescent sera of five children <2 years of age infected with GII.4-2009 NO. GII.4-2009 NO infection induced IgG seroconversion to all three tested NoV GII.4 variants. Homologous blocking antibodies to GII.4-2009 NO were detected in each convalescent sera. Fourfold increase in cross-blocking antibodies to GII.4-2012 Sydney was observed in 4/5 subjects, but no child developed cross-blocking antibodies to GII.4-1999. In conclusion, antibodies induced in young children after norovirus GII.4 infection are targeted against the causative variant and may cross-protect against strains that are closely related, but not with more distinct and earlier GII.4 genotypes. J. Med. Virol. 87:1656-1661, 2015. © 2015 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Single- and double-sided functionalized hybrid organic-inorganic Anderson polyoxomolybdates with GaIII and FeIII positioned as central heteroatoms have been synthesized in a mild, two-step synthesis in an aqueous medium. Compounds 1- 4 were isolated as hydrated salts, [TBA]3[GaMo6O18(OH)3{(OCH2)3CCH2OH}]×12 H2O ( 1) (TBA=tetrabutylammonium), Na3[FeMo6O18{(OCH2)3CCH2OH}2]×11 H2O ( 2), [TMA]2[GaMo6O18(OH)3{(OCH2)3CNH3}]×7 H2O ( 3) (TMA=tetramethylammonium), and Na[TMA]2[FeMo6O18(OH)3{(OCH2)3CNH3}](OH)×6 H2O ( 4). All the compounds were characterized based on single-crystal X-ray diffraction (SXRD), FTIR, UV/Vis, thermogravimetric, ESI-MS, NMR, and elemental analyses. Compound 1 was also crystallized with two smaller organic cations, giving [TMA]3[GaMo6O18(OH)3{(OCH2)3CCH2OH}]× n H2O ( 5) and [GDM]3[GaMo6O18(OH)3{(OCH2)3CCH2OH}]× n H2O ( 6) (GDM=guanidinium) and were characterized based on UV/Vis, NMR, FTIR, and elemental analyses. The use of these compounds as additives in macromolecular crystallography was investigated by examining their hydrolytic stability by using ESI-MS in a pH range of 4 to 9. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis showed that BSA remains intact in a solution containing up to 100 equivalents of 1 or 4 over more than four days at 20 °C. Zeta potential measurements demonstrate that 1- 4 induce charge inversions on the positively charged surface of BSA (1 mg mL−1) with concentrations starting as low as 1.29 m M for compounds 1 and 2, which have the highest negative surface charge. [ABSTRACT FROM AUTHOR]

Customer cocreation during the innovation process has recently been suggested to be a major source for firms' competitive advantage. Hereby, customers actively engage in a firm's innovation process and take over innovation activities traditionally performed by a firm's employees. Despite its suggested importance, previous research has revealed contradictory findings regarding its impact, the nature of involved customers, and the channels of communication that enable cocreation. To provide a more fine-grained picture, customer cocreated knowledge is first delineated into its key value dimensions of relevance, novelty, and costs, and then their impact on various innovation outcomes is investigated. Next, the study examines the antecedent role of customer determinants; that is, lead user characteristics and customer-firm closeness, on these knowledge value dimensions. Finally, we explore how these effects are moderated by the type of communication channel used. An empirical validation of the conceptual model is performed by means of survey data from 126 customer cocreation projects. The data analysis indicates that customer cocreation is most successful for the creation of highly relevant but moderately novel knowledge. Cocreation with customers who are closely related to the innovating firm results in more highly relevant knowledge at a low cost. Yet, cocreation with lead users produces novel and relevant knowledge. These effects are contingent on the richness and reach of the communication channels enabling cocreation. Overall, the findings shed light on opportunities and limitations of customer cocreation for innovation and reconcile determinants originating in relationship marketing and innovation management. At the same time, managers obtain recommendations for selecting customers and communication channels to enhance the success of their customer cocreation initiatives. [ABSTRACT FROM AUTHOR]

Summary Norovirus (NoV) -derived virus-like particles (VLPs) resemble empty shells of the virus and NoV P-particles contain only protruding domains of the NoV capsid. Both NoV-derived subviral particles show similar functionality and antigenicity in vitro and are considered to be potential vaccine candidates against NoV gastroenteritis. BALB/c mice were immunized with baculovirus-produced GII-4 VLPs or the corresponding Escherichia coli-produced P-particles by the intramuscular or intradermal route and the NoV-specific antibody and T-cell immune responses were compared. Elevated antibody levels were induced with a single VLP immunization, whereas P-particle immunization required a boost. High avidity antibodies were raised only by VLP immunization. VLP immunization resulted in a balanced T helper type 1/type 2 immune response whereas P-particles induced a T helper type 2-biased response. Only VLP immunization primed T cells for interferon-γ production. Most importantly, cross-reactive B and T cells were induced solely by VLP immunization. In addition, VLP antiserum blocked the binding of heterotypic VLPs to human histo-blood group antigen receptor and saliva. The findings in this study are relevant for the development of NoV vaccines. [ABSTRACT FROM AUTHOR]

Noroviruses (NoVs) are the second most common cause of viral gastroenteritis after rotavirus in children. NoV genotype GII-4 has emerged as the major type not only in outbreaks of NoV gastroenteritis but also endemic gastroenteritis among infants and young children worldwide. Using baculovirus-insect cell system virus-like particles (VLPs) of NoV genotype GII-4 and an uncommon genotype GII-12 were produced. These VLPs were used in enzyme-linked immunosorbent assays (ELISA) for detection of NoV-specific immunoglobulin G (IgG) and IgA antibodies in 492 serum specimens from Finnish children 0-14 years of age collected between 2006 and 2008. NoV IgG antibody prevalence was 47.3% in the age group 7-23 months and increased up to 91.2% after the age of 5 years. Avidity of NoV IgG antibodies was low in the primary infections while high avidity antibodies were detected in the recurrent infections of the older children. In GII-4 infections, the homologous antibody response to GII-4 VLPs was stronger than to GII-12 VLPs but cross-reactivity between GII-4 and GII-12 was observed. Binding of GII-4 VLPs to a putative carbohydrate antigen receptor H-type 3 could be blocked by sera from children not infected with NoV during a waterborne outbreak of acute gastroenteritis. Therefore, protection against NoV infection correlated with strong blocking activity. J. Med. Virol. 83:525-531, 2011. © 2011 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Dynamic networks of protein–protein interactions regulate numerous cellular processes and determine the ability to respond appropriately to environmental stimuli. However, the investigation of protein complex formation in living plant cells by methods such as fluorescence resonance energy transfer has remained experimentally difficult, time consuming and requires sophisticated technical equipment. Here, we report the implementation of a bimolecular fluorescence complementation (BiFC) technique for visualization of protein–protein interactions in plant cells. This approach relies on the formation of a fluorescent complex by two non-fluorescent fragments of the yellow fluorescent protein brought together by association of interacting proteins fused to these fragments (). To enable BiFC analyses in plant cells, we generated different complementary sets of expression vectors, which enable protein interaction studies in transiently or stably transformed cells. These vectors were used to investigate and visualize homodimerization of the basic leucine zipper (bZIP) transcription factor bZIP63 and the zinc finger protein lesion simulating disease 1 (LSD1) fromArabidopsisas well as the dimer formation of the tobacco 14-3-3 protein T14-3c. The interaction analyses of these model proteins established the feasibility of BiFC analyses for efficient visualization of structurally distinct proteins in different cellular compartments. Our investigations revealed a remarkable signal fluorescence intensity of interacting protein complexes as well as a high reproducibility and technical simplicity of the method in different plant systems. Consequently, the BiFC approach should significantly facilitate the visualization of the subcellular sites of protein interactions under conditions that closely reflect the normal physiological environment. [ABSTRACT FROM AUTHOR]

Calcium ions represent both an integrative signal and an important convergence point of many disparate signaling pathways. Calcium-binding proteins, like calcineurin B-like (CBL) proteins, have been implicated as important relays in calcium signaling. Here, we report the in vivo study of CBL1 function in Arabidopsis. Analyses of loss-of-function as well as CBL1-overexpressing lines indicate a crucial function of this calcium sensor protein in abiotic stress responses. Mutation of CBL1 impairs plant responses to drought and salt stresses and affects gene expression of cold-regulated genes, but does not affect abscisic acid (ABA) responsiveness. Conversely, overexpression of CBL1 reduces transpirational water loss and induces the expression of early stress-responsive transcription factors and stress adaptation genes in non-stressed plants. Together, our data indicate that the calcium sensor protein CBL1 may constitute an integrative node in plant responses to abiotic stimuli and contributes to the regulation of early stress-related transcription factors of the C-Repeat-Binding Factor/dehydration-responsive element (CBF/DREB) type. [ABSTRACT FROM AUTHOR]

Review: 297 refs. [ABSTRACT FROM AUTHOR]