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1.
Cells ; 13(17)2024 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-39273077

RESUMEN

Plastin-3 (PLS3) encodes T-plastin, an actin-bundling protein mediating the formation of actin filaments by which numerous cellular processes are regulated. Loss-of-function genetic defects in PLS3 are reported to cause X-linked osteoporosis and childhood-onset fractures. However, the molecular etiology of PLS3 remains elusive. Functional compensation by actin-bundling proteins ACTN1, ACTN4, and FSCN1 was investigated in zebrafish following morpholino-mediated pls3 knockdown. Primary dermal fibroblasts from six patients with a PLS3 variant were also used to examine expression of these proteins during osteogenic differentiation. In addition, Pls3 knockdown in the murine MLO-Y4 cell line was employed to provide insights in global gene expression. Our results showed that ACTN1 and ACTN4 can rescue the skeletal deformities in zebrafish after pls3 knockdown, but this was inadequate for FSCN1. Patients' fibroblasts showed the same osteogenic transdifferentiation ability as healthy donors. RNA-seq results showed differential expression in Wnt1, Nos1ap, and Myh3 after Pls3 knockdown in MLO-Y4 cells, which were also associated with the Wnt and Th17 cell differentiation pathways. Moreover, WNT2 was significantly increased in patient osteoblast-like cells compared to healthy donors. Altogether, our findings in different bone cell types indicate that the mechanism of PLS3-related pathology extends beyond actin-bundling proteins, implicating broader pathways of bone metabolism.


Asunto(s)
Diferenciación Celular , Glicoproteínas de Membrana , Proteínas de Microfilamentos , Osteogénesis , Pez Cebra , Pez Cebra/metabolismo , Pez Cebra/genética , Animales , Osteogénesis/genética , Humanos , Proteínas de Microfilamentos/metabolismo , Proteínas de Microfilamentos/genética , Glicoproteínas de Membrana/metabolismo , Glicoproteínas de Membrana/genética , Ratones , Fibroblastos/metabolismo , Osteoblastos/metabolismo , Proteínas de Pez Cebra/metabolismo , Proteínas de Pez Cebra/genética , Técnicas de Silenciamiento del Gen
2.
Artículo en Inglés | MEDLINE | ID: mdl-39289128

RESUMEN

In order for patients to gain the benefit of innovation in cardiac CT, it is necessary for coding, coverage, and payment to adapt to the novelty of algorithm-based healthcare procedures and services (ABHS). Appendix S to the CPT Code Set, the "AI Taxonomy", enables creation of discrete and differentiable codes for reimbursement of ABHS which has been clinically validated and FDA-labeled. Payment policy in OPPS and PFS is evolving to take account of the unique opportunities and issues arising from the clinical adoption of ABHS.

3.
J Integr Plant Biol ; 2024 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-39136601

RESUMEN

It has been proposed that cortical fine actin filaments are needed for the morphogenesis of pavement cells (PCs). However, the precise role and regulation mechanisms of actin filaments in PC morphogenesis are not well understood. Here, we found that Arabidopsis thaliana ACTIN DEPOLYMERIZING FACTOR9 (ADF9) is required for the morphogenesis of PC, which is negatively regulated by the R2R3 MYELOBLASTOSIS (MYB) transcription factor MYB52. In adf9 mutants, the lobe number of cotyledon PCs was significantly reduced, while the average lobe length did not differ significantly compared to that of wild type (Col-0), except for the variations in cell area and circularity, whereas the PC shapes in ADF9 overexpression seedlings showed different results. ADF9 decorated actin filaments, and colocalized with plasma membrane. The extent of filament bundling and actin filament bundling activity in adf9 mutant decreased. In addition, MYB52 directly targeted the promoter of ADF9 and negatively regulated its expression. The myb52-2 mutant showed increased lobe number and cell area, reduced cell circularity of PCs, and the PC phenotypes were suppressed when ADF9 was knocked out. Taken together, our data demonstrate that actin filaments play an important role in the morphogenesis of PC and reveal a transcriptional mechanism underlying MYB52 regulation of ADF9-mediated actin filament bundling in PC morphogenesis.

4.
Cell Rep ; 43(5): 114215, 2024 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-38728140

RESUMEN

Cells have robust wound repair systems to prevent further damage or infection and to quickly restore cell cortex integrity when exposed to mechanical and chemical stress. Actomyosin ring formation and contraction at the wound edge are major events during closure of the plasma membrane and underlying cytoskeleton during cell wound repair. Here, we show that all five Drosophila Septins are required for efficient cell wound repair. Based on their different recruitment patterns and knockdown/mutant phenotypes, two distinct Septin complexes, Sep1/Sep2/Pnut and Sep4/Sep5/Pnut, are assembled to regulate actin ring assembly, contraction, and remodeling during the repair process. Intriguingly, we find that these two Septin complexes have different F-actin bending activities. In addition, we find that Anillin regulates the recruitment of only one of two Septin complexes upon wounding. Our results demonstrate that two functionally distinct Septin complexes work side by side to discretely regulate actomyosin ring dynamics during cell wound repair.


Asunto(s)
Actinas , Proteínas de Drosophila , Septinas , Cicatrización de Heridas , Animales , Septinas/metabolismo , Actinas/metabolismo , Proteínas de Drosophila/metabolismo , Actomiosina/metabolismo , Drosophila melanogaster/metabolismo , Proteínas Contráctiles/metabolismo , Proteínas de Microfilamentos
5.
Heliyon ; 10(8): e29581, 2024 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-38681608

RESUMEN

The outbreak of the COVID-10 variant Omicron epidemic in Shanghai in 2022 had a huge impact on residents' food security. This study examines the roles, challenges, and sustainability of online community group food purchasing by analyzing survey data collected from 1168 households in Shanghai between March and May 2022, in the aftermath of COVID-19. This study demonstrates that online community group food purchasing played a crucial role in ensuring residents' food access and food security during the pandemic. However, this study also reveals that residents expressed concerns about the risk of epidemic transmission, food safety, increased prices, and difficulty in safeguarding rights. Only 21.5 % of residents are willing to continue using online community group purchasing. Based on the above conclusions, this study offers some suggestions.

6.
Open Biol ; 14(3): 230376, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38503329

RESUMEN

Fascin-1-mediated actin-bundling activity is central to the generation of plasma membrane protrusions required for cell migration. Dysregulated formation of cellular protrusions is observed in metastatic cancers, where they are required for increased invasiveness, and is often correlated with increased Fascin-1 abundance. Therefore, there is interest in generating therapeutic Fascin-1 inhibitors. We present the identification of Nb 3E11, a nanobody inhibitor of Fascin-1 actin-bundling activity and filopodia formation. The crystal structure of the Fascin-1/Nb 3E11 complex reveals the structural mechanism of inhibition. Nb 3E11 occludes an actin-binding site on the third ß-trefoil domain of Fascin-1 that is currently not targeted by chemical inhibitors. Binding of Nb 3E11 to Fascin-1 induces a conformational change in the adjacent domains to stabilize Fascin-1 in an inhibitory state similar to that adopted in the presence of small-molecule inhibitors. Nb 3E11 could be used as a tool inhibitor molecule to aid in the development of Fascin-1 targeted therapeutics.


Asunto(s)
Actinas , Proteínas Portadoras , Proteínas de Microfilamentos , Seudópodos , Actinas/metabolismo , Seudópodos/metabolismo , Unión Proteica , Movimiento Celular
7.
Soc Sci Med ; 344: 116636, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38394862

RESUMEN

Health programs/services are often bundled, allowing for both substitution and complementarity. We adapt Discrete Choice Experiments to capture bundling, with application to a case study of exercise and nutrition; complementarity arises due to the goal of improving health. Our contributions are (1) to present a menu-based choice experiment to explore bundling; (2) to analyse the menu-based data using an extension of the choice set generation model (GenL) to account for correlations between bundles and component singles. A nationally representative sample of 333 Australians chose between a nutrition program only; exercise program only; both nutrition and exercise programs; or their status quo. Overall, we show that by incorporating the menu choice task and introducing the combined alternative, we capture a significant portion of the population seeking both exercise and nutrition components. We estimate a latent class GenL model, and identify two latent classes: Class 1 preferred to choose programs on offer, and Class 2 was more price sensitive and had a stronger preference for staying with their status quo. We show in the post-estimation analysis that heterogeneity in preferences translates into heterogeneity in the way alternatives are bundled, indicating that the combined offering is appealing to specific classes of individuals who prefer bundling. By implementing the menu choice task, researchers and policymakers can effectively identify, cater to and influence the demand for combined exercise and nutrition options, leading to more targeted and impactful interventions in promoting healthier lifestyle choices.


Asunto(s)
Conducta de Elección , Servicios de Salud , Prioridad del Paciente , Humanos , Pueblos de Australasia , Australia , Ejercicio Físico , Estilo de Vida Saludable
8.
Biol Open ; 13(3)2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38372564

RESUMEN

The actin cytoskeleton is a dynamic filamentous network that assembles into specialized structures to enable cells to perform essential processes. Direct visualization of fluorescently-labeled cytoskeletal proteins has provided numerous insights into the dynamic processes that govern the assembly of actin-based structures. However, accurate analysis of these experiments is often complicated by the interdependent and kinetic natures of the reactions involved. It is often challenging to disentangle these processes to accurately track their evolution over time. Here, we describe two programs written in the MATLAB programming language that facilitate counting, length measurements, and quantification of bundling of actin filaments visualized in fluorescence micrographs. To demonstrate the usefulness of our programs, we describe their application to the analysis of two representative reactions: (1) a solution of pre-assembled filaments under equilibrium conditions, and (2) a reaction in which actin filaments are crosslinked together over time. We anticipate that these programs can be applied to extract equilibrium and kinetic information from a broad range of actin-based reactions, and that their usefulness can be expanded further to investigate the assembly of other biopolymers.


Asunto(s)
Citoesqueleto de Actina , Actinas , Citoesqueleto , Proteínas del Citoesqueleto , Microscopía
9.
Bioresour Technol ; 396: 130445, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38346595

RESUMEN

To realize the intelligent production of straw bales and improve their economy, the density of straw bales in the working process of large-scale steel roller-type round balers must be measured in real time. Therefore, this study analyzes the forces acting on steel rollers and bales in the bale rolling process, constructs a mathematical model to predict the density of molded bales, and proposes a method for dynamically measuring the density of bales in a round bale machine. Sunflower straw was selected as the test material, and a bale density model validation test was conducted at a test stand. The results showed that the accuracy of the measured bale density of the data acquisition system ranged from 93% to 97%, verifying that the mathematical model for bale density prediction had good accuracy. This study provided an effective strategy for round baler design.


Asunto(s)
Modelos Teóricos
10.
Am J Health Promot ; 38(2): 167-176, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37935039

RESUMEN

PURPOSE: "Behavioral bundling" is a theory that explains how some health behaviors reinforce one another. This study aims to investigate the relationship between preventive health behaviors (PHBs) and safe firearm storage. DESIGN: This study used a cross-sectional design using 2017 Behavioral Risk Factor Surveillance Survey data. SETTING: Survey participants resided in California, Idaho, Kansas, Oregon, Texas, and Utah. SUBJECTS: There were 12,817 people living in households with a firearm included in this study. MEASURES: We classified individuals' engagement in 5 PHBs: cholesterol screening, influenza immunization, physical activity, primary care, and seatbelt use. We defined safe firearm storage as storing a firearm unloaded, or loaded but locked. ANALYSIS: Using Poisson regression models, we calculated adjusted prevalence ratios (aPRs) to estimate the association between engagement in the five PHBs with safe firearm storage. RESULTS: Most firearm owners reported safe firearm storage (80.3%). The prevalence of safe firearm storage was 3% higher for each additional PHB engaged in (aPR = 1.03 [1.01, 1.05]). There was a higher prevalence of safe firearm storage among those who always wore a seatbelt while driving or riding in a car compared to those who did not (aPR = 1.12 [1.05, 1.18]). CONCLUSION: This study found preliminary evidence to suggest that engagement in seatbelt usage may be bundled with safe firearm storage, though we are not able to determine causality.


Asunto(s)
Conductas Relacionadas con la Salud , Servicios Preventivos de Salud , Humanos , Seguridad , Sistema de Vigilancia de Factor de Riesgo Conductual , Estudios Transversales
11.
Bioessays ; 46(2): e2300182, 2024 02.
Artículo en Inglés | MEDLINE | ID: mdl-38044581

RESUMEN

Transport of macromolecules from the nucleus to the cytoplasm is essential for nearly all cellular and developmental events, and when mis-regulated, is associated with diseases, tumor formation/growth, and cancer progression. Nuclear Envelope (NE)-budding is a newly appreciated nuclear export pathway for large macromolecular machineries, including those assembled to allow co-regulation of functionally related components, that bypasses canonical nuclear export through nuclear pores. In this pathway, large macromolecular complexes are enveloped by the inner nuclear membrane, transverse the perinuclear space, and then exit through the outer nuclear membrane to release its contents into the cytoplasm. NE-budding is a conserved process and shares many features with nuclear egress mechanisms used by herpesviruses. Despite its biological importance and clinical relevance, little is yet known about the regulatory and structural machineries that allow NE-budding to occur in any system. Here we summarize what is currently known or proposed for this intriguing nuclear export process.


Asunto(s)
Herpesviridae , Membrana Nuclear , Membrana Nuclear/metabolismo , Transporte Activo de Núcleo Celular/fisiología , Herpesviridae/metabolismo , Citoplasma/metabolismo , Núcleo Celular/metabolismo
12.
Artículo en Chino | WPRIM (Pacífico Occidental) | ID: wpr-1024108

RESUMEN

Objective To observe the effectiveness of fluorescence labeling-based assay bundle intervention in the prevention and control of multidrug-resistant organism(MDRO)infection.Methods Patients who were detected MDRO in a hospital from January to December 2022 were selected as the research subjects.MDRO monitoring data and implementation status of prevention and control measures were collected.Fluorescence labeling assay was adopted to monitor the cleaning and disinfection effectiveness of the surrounding object surface of the bed units.Based on the bundled prevention and control measures as well as management mode of the pre-intervention group,the post-intervention group implemented enhanced rectification measures for the problems found by the pre-interven-tion group.Changes in relevant indicators between January-June 2022(before intervention)and July-December 2022(after intervention)were compared.Results There were 136 MDRO-infected patients in the pre-intervention group,208 MDRO strains were detected and 10 healthcare-associated infection(HAI)occurred.There were 128 MDRO-infected patients in the post-intervention group,198 MDRO strains were detected and 9 HAI occurred.Af-ter intervention,the total detection rates of methicillin-resistant Staphylococcus aureus(MRSA),carbapenem-re-sistant Acinetobacter baumannii(CRAB),and total MDRO from patients decreased significantly compared to before intervention(all P<0.05).After intervention,the detection rates of MRSA,carbapenem-resistant Pseudomonas aeruginosa(CRPA),CRAB,and total MDRO from the surrounding object surface were all lower than those before intervention(all P<0.05).The detection rate of MDRO from surrounding object surface before intervention was 34.52%,which showed a decreased trend after intervention(P<0.05).The clearance rate of fluorescent labeled markers before intervention was 41.84%,which showed an upward trend after implementing intervention measures(from July to December),and increased to 85.00%at the end of intervention(November-December).The comp-liance rates of issuing isolation medical orders,placing isolation labels,using medical supplies exclusively,and cor-rectly handling medical waste after intervention have all increased compared to before intervention(all P<0.05).Conclusion Adopting fluorescence labeling-based assay bundle intervention can effectively improve the effectiveness of MDRO infection prevention and control.

13.
Adv Sci (Weinh) ; 10(36): e2304885, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37909346

RESUMEN

Excessive mitochondrial fission following ischemia and hypoxia relies on the formation of contacts between the endoplasmic reticulum and mitochondria (ER-Mito); however, the specific mechanisms behind this process remain unclear. Confocal microscopy and time course recording are used to investigate how ischemia and hypoxia affect the activation of dynamin-related protein 1 (Drp1), a protein central to mitochondrial dynamics, ER-Mito interactions, and the consequences of modifying the expression of Drp1, shroom (Shrm) 4, and inverted formin (INF) 2 on ER-Mito contact establishment. Both Drp1 activation and ER-Mito contact initiation cause excessive mitochondrial fission and dysfunction under ischemic-hypoxic conditions. The activated form of Drp1 aids in ER-Mito contact initiation by recruiting Shrm4 and promoting actin bundling between the ER and mitochondria. This process relies on the structural interplay between INF2 and scattered F-actin on the ER. This study uncovers new roles of cytoplasmic Drp1, providing valuable insights for devising strategies to manage mitochondrial imbalances in the context of ischemic-hypoxic injury.


Asunto(s)
Actinas , Dinaminas , Humanos , Actinas/metabolismo , Dinaminas/metabolismo , Mitocondrias/metabolismo , Retículo Endoplásmico/metabolismo , Isquemia , Hipoxia/metabolismo
14.
bioRxiv ; 2023 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-38014090

RESUMEN

Cells have robust wound repair systems to prevent further damage or infection and to quickly restore cell cortex integrity when exposed to mechanical and chemical stress. Actomyosin ring formation and contraction at the wound edge are major events during closure of the plasma membrane and underlying cytoskeleton during cell wound repair. Here, we show that all five Drosophila Septins are required for efficient cell wound repair. Based on their different recruitment patterns and knockdown/mutant phenotypes, two distinct Septin complexes, Sep1-Sep2-Pnut and Sep4-Sep5-Pnut, are assembled to regulate actin ring assembly, contraction, and remodeling during the repair process. Intriguingly, we find that these two Septin complexes have different F-actin bending activities. In addition, we find that Anillin regulates the recruitment of only one of two Septin complexes upon wounding. Our results demonstrate that two functionally distinct Septin complexes work side-by-side to discretely regulate actomyosin ring dynamics during cell wound repair.

15.
Curr Biol ; 33(20): 4484-4495.e5, 2023 10 23.
Artículo en Inglés | MEDLINE | ID: mdl-37797614

RESUMEN

How actin filaments are spatially organized and remodeled into diverse higher-order networks in vivo is still not well understood. Here, we report an unexpected F-actin "coalescence" activity driven by cyclase-associated protein (CAP) and enhanced by its interactions with actin-binding protein 1 (Abp1). We directly observe S. cerevisiae CAP and Abp1 rapidly transforming branched or linear actin networks by bundling and sliding filaments past each other, maximizing filament overlap, and promoting compaction into bundles. This activity does not require ATP and is conserved, as similar behaviors are observed for the mammalian homologs of CAP and Abp1. Coalescence depends on the CAP oligomerization domain but not the helical folded domain (HFD) that mediates its functions in F-actin severing and depolymerization. Coalescence by CAP-Abp1 further depends on interactions between CAP and Abp1 and interactions between Abp1 and F-actin. Our results are consistent with a mechanism in which the formation of energetically favorable sliding CAP and CAP-Abp1 crosslinks drives F-actin bundle compaction. Roles for CAP and CAP-Abp1 in actin remodeling in vivo are supported by strong phenotypes arising from deletion of the CAP oligomerization domain and by genetic interactions between sac6Δ and an srv2-301 mutant that does not bind Abp1. Together, these observations identify a new actin filament remodeling function for CAP, which is further enhanced by its direct interactions with Abp1.


Asunto(s)
Actinas , Proteínas de Saccharomyces cerevisiae , Animales , Actinas/metabolismo , Proteínas del Citoesqueleto/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Citoesqueleto de Actina/metabolismo , Mamíferos
16.
Development ; 150(12)2023 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-37314175

RESUMEN

Cytokinesis is the last step of cell division, when one cell physically divides into two cells. Cytokinesis is driven by an equatorial contractile ring and signals from antiparallel microtubule bundles (the central spindle) that form between the two masses of segregating chromosomes. Bundling of central spindle microtubules is essential for cytokinesis in cultured cells. Using a temperature-sensitive mutant of SPD-1, the homolog of the microtubule bundler PRC1, we demonstrate that SPD-1 is required for robust cytokinesis in the Caenorhabditis elegans early embryo. SPD-1 inhibition results in broadening of the contractile ring, creating an elongated intercellular bridge between sister cells at the last stages of ring constriction that fails to seal. Moreover, depleting anillin/ANI-1 in SPD-1-inhibited cells results in myosin loss from the contractile ring during the second half of furrow ingression, which in turn results in furrow regression and cytokinesis failure. Our results thus reveal a mechanism involving the joint action of anillin and PRC1, which operates during the later stages of furrow ingression to ensure continued functioning of the contractile ring until cytokinesis is complete.


Asunto(s)
Proteínas de Caenorhabditis elegans , Citocinesis , Animales , Proteínas Contráctiles/genética , Miosinas , Microtúbulos , Caenorhabditis elegans , Proteínas de Microfilamentos , Proteínas de Caenorhabditis elegans/genética
17.
J Dr Nurs Pract ; 2023 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-37369451

RESUMEN

Background: Globally, cervical cancer is the fourth most common cancer in females, with more than 70% caused by the human papillomavirus (HPV) genotype 16/18. The high mortality rate could be reduced with early intervention through the administration of the HPV vaccine. Objective: The purpose of this project was to increase the HPV vaccination rates in the primary care setting by bundling the HPV vaccine with routine vaccines (Tdap), meningococcal, and influenza. Method:The electronic medical record was used to identify patients due for the HPV vaccine series. Each patient received a vaccine reminder letter detailing each vaccine recommended during the visit and their rights to accept or decline the vaccines. Results: Findings revealed bundling the vaccine increased the HPV vaccination rates up to 400% when compared with the previous year. Conclusion: This implementation process has the potential to improve the health of the population by increasing the HPV vaccination rates and decreasing the high mortality rates and costs associated with cervical cancers or precancers. Implications for Nursing: The evidence-based practice of bundling the HPV vaccine, educating the staff, and providing written information to the patients is recommended for advanced practical registered nurses to improve the health of the population.

18.
Health Care Manag Sci ; 26(3): 477-500, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37199873

RESUMEN

During the COVID-19 pandemic, there has been considerable research on how regional and country-level forecasting can be used to anticipate required hospital resources. We add to and build on this work by focusing on ward-level forecasting and planning tools for hospital staff during the pandemic. We present an assessment, validation, and deployment of a working prototype forecasting tool used within a modified Traffic Control Bundling (TCB) protocol for resource planning during the pandemic. We compare statistical and machine learning forecasting methods and their accuracy at one of the largest hospitals (Vancouver General Hospital) in Canada against a medium-sized hospital (St. Paul's Hospital) in Vancouver, Canada through the first three waves of the COVID-19 pandemic in the province of British Columbia. Our results confirm that traditional statistical and machine learning (ML) forecasting methods can provide valuable ward-level forecasting to aid in decision-making for pandemic resource planning. Using point forecasts with upper 95% prediction intervals, such forecasting methods would have provided better accuracy in anticipating required beds on COVID-19 hospital units than ward-level capacity decisions made by hospital staff. We have integrated our methodology into a publicly available online tool that operationalizes ward-level forecasting to aid with capacity planning decisions. Importantly, hospital staff can use this tool to translate forecasts into better patient care, less burnout, and improved planning for all hospital resources during pandemics.


Asunto(s)
COVID-19 , Humanos , COVID-19/epidemiología , Pandemias , Hospitales , Predicción
19.
Cell Rep ; 42(4): 112405, 2023 04 25.
Artículo en Inglés | MEDLINE | ID: mdl-37071535

RESUMEN

Upon activation, vinculin reinforces cytoskeletal anchorage during cell adhesion. Activating ligands classically disrupt intramolecular interactions between the vinculin head and tail domains that bind to actin filaments. Here, we show that Shigella IpaA triggers major allosteric changes in the head domain, leading to vinculin homo-oligomerization. Through the cooperative binding of its three vinculin-binding sites (VBSs), IpaA induces a striking reorientation of the D1 and D2 head subdomains associated with vinculin oligomerization. IpaA thus acts as a catalyst producing vinculin clusters that bundle actin at a distance from the activation site and trigger the formation of highly stable adhesions resisting the action of actin relaxing drugs. Unlike canonical activation, vinculin homo-oligomers induced by IpaA appear to keep a persistent imprint of the activated state in addition to their bundling activity, accounting for stable cell adhesion independent of force transduction and relevant to bacterial invasion.


Asunto(s)
Proteínas Bacterianas , Shigella , Proteínas Bacterianas/metabolismo , Antígenos Bacterianos/metabolismo , Actinas/metabolismo , Vinculina/metabolismo , Shigella/metabolismo , Unión Proteica
20.
Planta ; 257(4): 71, 2023 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-36862199

RESUMEN

MAIN CONCLUSIONS: STD1 specifically interacts with MAP65-5 in rice and they cooperatively control microtubule bundles in phragmoplast expansion during cell division. Microtubules play critical roles during the cell cycle progression in the plant cell. We previously reported that STEMLESS DWARF 1 (STD1), a kinesin-related protein, was localized specifically to the phragmoplast midzone during telophase to regulate the lateral expansion of phragmoplast in rice (Oryza sativa). However, how STD1 regulates microtubule organization remains unknown. Here, we found that STD1 interacted directly with MAP65-5, a member of the microtubule-associated proteins (MAPs). Both STD1 and MAP65-5 could form homodimers and bundle microtubules individually. Compared with MAP65-5, the microtubules bundled by STD1 were disassembled completely into single microtubules after adding ATP. Conversely, the interaction of STD1 with MAP65-5 enhanced the microtubule bundling. These results suggest STD1 and MAP65-5 might cooperatively regulate microtubule organization in the phragmoplast at telophase.


Asunto(s)
Proteínas Asociadas a Microtúbulos , Oryza , Proteínas Asociadas a Microtúbulos/genética , Cinesinas , Microtúbulos , Mitosis
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