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The surface of a living cell provides a platform for receptor signaling, protein sorting, transport, and endocytosis, whose regulation requires the local control of membrane organization. Previous work has revealed a role for dynamic actomyosin in membrane protein and lipid organization, suggesting that the cell surface behaves as an active composite composed of a fluid bilayer and a thin film of active actomyosin. We reconstitute an analogous system in vitro that consists of a fluid lipid bilayer coupled via membrane-associated actin-binding proteins to dynamic actin filaments and myosin motors. Upon complete consumption of ATP, this system settles into distinct phases of actin organization, namely bundled filaments, linked apolar asters, and a lattice of polar asters. These depend on actin concentration, filament length, and actin/myosin ratio. During formation of the polar aster phase, advection of the self-organizing actomyosin network drives transient clustering of actin-associated membrane components. Regeneration of ATP supports a constitutively remodeling actomyosin state, which in turn drives active fluctuations of coupled membrane components, resembling those observed at the cell surface. In a multicomponent membrane bilayer, this remodeling actomyosin layer contributes to changes in the extent and dynamics of phase-segregating domains. These results show how local membrane composition can be driven by active processes arising from actomyosin, highlighting the fundamental basis of the active composite model of the cell surface, and indicate its relevance to the study of membrane organization.

Fusion-associated small transmembrane (FAST) proteins are a diverse family of nonstructural viral proteins. Once expressed on the plasma membrane of infected cells, they drive fusion with neighboring cells, increasing viral spread and pathogenicity. Unlike viral fusogens with tall ectodomains that pull two membranes together through conformational changes, FAST proteins have short fusogenic ectodomains that cannot bridge the intermembrane gap between neighboring cells. One orthoreovirus FAST protein, p14, has been shown to hijack the actin cytoskeleton to drive cell-cell fusion, but the actin adaptor-binding motif identified in p14 is not found in any other FAST protein. Here, we report that an evolutionarily divergent FAST protein, p22 from aquareovirus, also hijacks the actin cytoskeleton but does so through different adaptor proteins, Intersectin-1 and Cdc42, that trigger N-WASP–mediated branched actin assembly. We show that despite using different pathways, the cytoplasmic tail of p22 can replace that of p14 to create a potent chimeric fusogen, suggesting they are modular and play similar functional roles. When we directly couple p22 with the parallel filament nucleator formin instead of the branched actin nucleation promoting factor N-WASP, its ability to drive fusion is maintained, suggesting that localized mechanical pressure on the plasma membrane coupled to a membrane-disruptive ectodomain is sufficient to drive cell-cell fusion. This work points to a common biophysical strategy used by FAST proteins to push rather than pull membranes together to drive fusion, one that may be harnessed by other short fusogens responsible for physiological cell-cell fusion.

The present paper is a review of the available literature on the significance of forage fish, the plethora of services they provide, and the threats faced by them. Forage fish are pelagic planktivorous species that operate as conduits of energy between the lower trophic level (plankton) and the upper trophic level (predators). A variety of ecosystem services are provided by them, from serving as prey for higher trophic levels to producing fish meal and oil. Forage fish have a consumption value for humans and cultural importance to many societies. Forage fish have faced constant natural and anthropogenic threats in the past, resulting in numerous fish collapses which subsequently impacted their predators. The economic benefit provided by forage fish has been estimated to be approximately $ 18.7 billion per annum. An introspection of the data on ecosystem services revealed lack of data on regulating and cultural services, eventually leading to a monetary underestimation and their commercial prioritization over the wider benefits they provide.

Recent in-vivo studies have revealed that several membrane proteins are driven to form nanoclusters by active contractile flows arising from F-actin and myosin at the cortex. The mechanism of clustering was shown to be arising from the dynamic patterning of transient contractile platforms (asters) generated by actin and myosin. Myosin-II, which assemble as minifilaments consisting of tens of myosin heads, are rather bulky structures and hence a concern could be that steric considerations might obstruct the emergence of nanoclustering. Here, using coarse-grained, agent-based simulations that respect the size of constituents, we find that in the presence of steric hindrance, the patterns exhibited by actomyosin in two dimensions, do not resemble the steady state patterns observed in our in-vitro reconstitution of actomyosin on a supported bilayer. We then perform simulations in a thin rectangular slab, allowing the separation of a layer of actin filaments from those of myosin-II minifilaments. This recapitulates the observed features of in-vitro patterning. Using super resolution microscopy, we find direct evidence for stratification in our in-vitro system. Our study suggests the possibility that molecular stratification may be an important organising feature of the cortical cytoskeleton in-vivo.

Fusion-associated small transmembrane (FAST) proteins are a diverse family of non-structural viral proteins that, once expressed on the plasma membrane of infected cells, drive fusion with neighboring cells, increasing viral spread and pathogenicity. Unlike viral fusogens with tall ectodomains that pull two membranes together through conformational changes, FAST proteins have short fusogenic ectodomains that cannot bridge the inter-membrane gap between neighboring cells. One orthoreovirus FAST protein, p14, has been shown to hijack the actin cytoskeleton to drive cell-cell fusion, but the actin adaptor-binding motif identified in p14 is not found in any other FAST protein. Here, we report that an evolutionarily divergent FAST protein, p22 from aquareovirus, also hijacks the actin cytoskeleton but does so through different adaptor proteins, Intersectin-1 and Cdc42, that trigger N-WASP-mediated branched actin assembly. We show that despite using different pathways, the cytoplasmic tails of p22 and p14 can be exchanging to create a potent chimeric fusogen, suggesting they are modular and play similar functional roles. When we replace p22's branched actin nucleator, N-WASP, with the parallel filament nucleator, formin, its ability to drive fusion is maintained, indicating that localized mechanical pressure on the plasma membrane coupled to a membrane-disruptive ectodomain is sufficient to drive cell-cell fusion. This work points to a common biophysical strategy used by FAST proteins to push rather than pull membranes together to drive fusion, one that may be harnessed by other short fusogens responsible for physiological cell-cell fusion. Competing Interest Statement The authors have declared no competing interest.

Root-knot nematodes (Meloidogyne spp.) are sedentary endoparasites that cause severe economic losses to agricultural crops globally. Due to the regulations of the European Union on the application of nematicides, it is crucial now to discover eco-friendly control strategies for nematode management. Biocontrol is one such safe and reliable method for managing these polyphagous nematodes. Biocontrol agents not only control these parasitic nematodes but also improve plant growth and induce systemic resistance in plants against a variety of biotic stresses. A wide range of organisms such as bacteria, fungi, viruses, and protozoans live in their natural mode as nematode antagonists. Various review articles have discussed the role of biocontrol in nematode management in general, but a specific review on biocontrol of root-knot nematodes is not available in detail. This review, therefore, focuses on the biocontrol of root-knot nematodes by discussing their important known antagonists, modes of action, and interactions.

Alternative methods are needed to replace chemical nematicides because they have the potential to damage beneficial soil microbial diversity. Therefore, the present work was done to elucidate the soil ameliorative, plant-growth-promoting, and nematicidal properties of fly ash. A random block-designed pot experiment was conducted during the period, December 2018–February 2019. Seeds of carrot ( Daucus carota L . ) were sown under natural conditions in clay pots containing a growth medium comprising of field soil amended with different levels of fly ash. Plants were inoculated with Meloidogyne incognita that were molecularly characterized using 18S and D2/D3 fragments of 28S rDNA and morphologically through perineal pattern arrangement. The results revealed that fly ash application improved the soil’s important physicochemical characteristics. The inoculation of M. incognita significantly reduced the plant growth, yield, and pigment content of carrot compared to the untreated uninoculated plants. Carrot grown in 15% fly ash (85:15 w/w field soil:fly ash) growth substrate had significantly ( P ≤ 0.05) improved plant growth, yield, and pigment content as compared to the untreated inoculated plants. Moreover, the proline content and the activity of superoxide dismutase (SOD) and catalase (CAT) were enhanced by applying 15% fly ash. Fly ash amendment to the soil not only improved plant growth and yield but also reduced the gall index and egg mass index per root system of the carrot as well. Our results, therefore, suggest that 15% fly ash can be used in a sustainable way to improve the growth, yield, and resistance of carrot against the infection of M. incognita . Graphical abstract

SCARB1 belongs to class B of Scavenger receptors (SRs) that are known to be involved in binding and endocytosis of various pathogens. SRs have emerging role in regulating innate immunity and host–pathogen interactions by acting in co-ordination with Toll-like receptors.Query Little is known about the function of SCARB1 in milk-derived mammary epithelial cells (MECs). This study reports the role of SCARB1 in infection and its potential association in TLR4 signaling on bacterial challenge in Goat mammary epithelial cells (GMECs). The novelty in the establishment of MEC culture lies in the method that aims to enhance the viability of the cells with intact characteristics upto a higher passage number. We represent MEC culture to be used as a potential infection model for deeper understanding of animal physiology especially around the mammary gland. On E.coli challenge the expression of SCARB1 was significant in induced GMECs at 6 h. Endoribonuclease-esiRNA based silencing of SCARB1 affects the expression of TLR4 and its pathways i.e. MyD88 and TRIF pathways on infection. Knockdown also affected the endocytosis of E.coli in GMECs demonstrating that  E.coli  uses SCARB1 function to gain entry in cells. Furthermore, we predict 3 unique protein structures of uncharacterized SCARB1 ( Capra hircus) protein. Overall, we highlight SCARB1 as a main participant in host defence and its function in antibacterial advances to check mammary gland infections. 77BMn9mgrsGEVLyNf1hg2w Video Abstract

Introduction Newer adhesive systems are available eliminating the separate priming step during the bonding procedure thereby reducing the chances of introduction of error during bonding. The purpose of this study was to compare the shear bond strength of a primer-incorporated adhesive with that of a self-etching primer system and conventional bonding system. Materials and method Sixty-six extracted human premolars were cleaned, mounted, and randomly divided into three groups. In group A (control), 22 teeth were bonded with stainless steel orthodontic brackets using the conventional bonding system; in group B, 22 teeth were bonded using a self-etching primer system (Transbond Plus SEP, 3M Unitek, Monrovia, CA) and in group C, 22 teeth were bonded using the new primer-incorporated adhesive system (GC Ortho Connect, GC Orthodontics, Breckerfeld, Germany). After bonding, the teeth were stored in artificial saliva at 37 C for 24 hours and debonded with a universal testing machine. The adhesive remnant index (ARI) was also evaluated. Statistical analysis was done using one-way ANOVA to compare the shear bond strength values among the three groups and Kruskal Wallis test was used for comparison of ARI scores. Results The SBS values in group A (11.60 ± 2.95 MPa), group B (9.44 ± 4.46 MPa) and group C (12.68 ± 6.25 MPa) were found to be comparable with no statistically significant difference. The ARI scores were also similar among the tested groups with the predominant site of bond failure being the bracket-adhesive interface indicating a safe bond-failure site. Conclusion GC Ortho Connect was found have clinically acceptable shear bond strength values that are comparable with that of self-etching primer and conventional bonding system. Therefore, it can be used effectively for saving the clinician's chairside time by reduction in the number of steps during bonding without compromising on the bond strength.