Flagella, the locomotion organelles of bacteria, extend from the cytoplasm to the cell exterior. External flagellar proteins are synthesized in the cytoplasm and exported by the flagellar type III ...secretion system. Soluble components of the flagellar export apparatus, FliI, FliH, and FliJ, have been implicated to carry late export substrates in complex with their cognate chaperones from the cytoplasm to the export gate. The importance of the soluble components in the delivery of the three minor late substrates FlgK, FlgL (hook–filament junction) and FliD (filament-cap) has been convincingly demonstrated, but their role in the transport of the major filament component flagellin (FliC) is still unclear.
We have used continuous ATPase activity measurements and quartz crystal microbalance (QCM) studies to characterize interactions between the soluble export components and flagellin or the FliC:FliS substrate–chaperone complex. As controls, interactions between soluble export component pairs were characterized providing Kd values. FliC or FliC:FliS did not influence the ATPase activity of FliI alone or in complex with FliH and/or FliJ suggesting lack of interaction in solution. Immobilized FliI, FliH, or FliJ did not interact with FliC or FliC:FliS detected by QCM. The lack of interaction in the fluid phase between FliC or FliC:FliS and the soluble export components, in particular with the ATPase FliI, suggests that cells use different mechanisms for the export of late minor substrates, and the major substrate, FliC. It seems that the abundantly produced flagellin does not require the assistance of the soluble export components to efficiently reach the export gate.
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•The flagellar export system transfers subunits from the cytoplasm to the filament.•FliI, FliH, and FliJ are soluble components of the export system.•They are thought to deliver chaperoned late substrates to the export gate.•Free or chaperoned FliC does not interact with the soluble components in solution.•The soluble components are not required for FliC delivery to the export gate.
APPLICATION OF AIRBORNE DATA TO MONITOR URBAN INFRASTRUCTURE OBJECTS Brovkina, O.; Kopkáně, D.; Polák, M. ...
International archives of the photogrammetry, remote sensing and spatial information sciences.,
06/2023, Volume:
XLVIII-5/W2-2023
Journal Article, Conference Proceeding
Peer reviewed
Open access
The paper demonstrates the application of hyperspectral data of Flight Laboratory of Imaging Systems (FLIS, https://olc.czechglobe.cz/en) to participate in three practical tasks of urban environment ...in the Czech Republic: 1/identification of asbestos-cement roofs on buildings; 2/monitoring of thermal regime of municipal solid waste landfill, and 3/estimation of perceived temperature in different parts of the city. These applications benefited from the airborne hyperspectral methods' ability to collect detailed spectral information, assess material composition, and extract biophysical parameters.
Assembly of the long helical filament of the bacterial flagellum requires polymerisation of ca 20,000 flagellin (FliC) monomeric subunits into the growing structure extending from the cell surface. ...Here, we show that export of Salmonella flagellin is facilitated specifically by a cytosolic protein, FliS, and that FliS binds to the FliC C-terminal helical domain, which contributes to stabilisation of flagellin subunit interactions during polymerisation. Stable complexes of FliS with flagellin were assembled efficiently in vitro, apparently by FliS homodimers binding to FliC monomers. The data suggest that FliS acts as a substrate-specific chaperone, preventing premature interaction of newly synthesised flagellin subunits in the cytosol. Compatible with this view, FliS was able to prevent in vitro polymerisation of FliC into filaments.
Wireless sensor networks (WSNs) are predominantly used for monitoring applications. The sensor nodes are resource-constrained devices, and hence efficient energy utilization of these nodes is one of ...the major challenges. The communication distances directly impact on the energy consumption of the sensor nodes. Clustering methods are popularly used to reduce communication distances and prolong the network lifetime. Multi-sink deployment is another method to reduce communication distances. It also resolves congestion and hotspot issues. In multi-sink WSNs, the number of sinks to be considered is a challenging task as it affects the network topology, lifetime and deployment cost. In this research work, multi-sink deployment and clustering scheme with sink selection algorithm are jointly proposed to maximize the network lifetime and minimize the deployment cost. An iterative filtering model is proposed to estimate optimal number of sinks, while sink positions are determined based on Fuzzy logic inference system (FLIS). Fuzzy-c-means algorithm is used to form balanced clusters in the network. Cluster representative and sink selection processes are based on FLIS. The proposed optimal multi-sink deployment scheme reduces the deployment cost and the propagation delay of the system, while enhancing the network lifetime. The proposed scheme is also energy efficient in the case of higher node density. Hence, the proposed scheme can be suitably implemented for large-scale monitoring applications of WSNs.
The Salmonella FliS flagellar export chaperone is a highly α‐helical protein. Proteolytic experiments suggest that FliS has a compact core. However, the calorimetric melting profile of FliS does not ...show any melting transition in the 25–110 °C temperature range. Circular dichroism measurements reveal that FliS is losing its helical structure over a broad temperature range upon heating. These observations indicate that FliS unfolds in a noncooperative way and its native state shows features reminiscent of the molten globule state of proteins possessing substantial structural plasticity. As FliS has several binding partners within the cell, conformational adaptability seems to be an essential requirement to fulfill its multiple roles.
The FliS flagellar export chaperone is an antiparallel four‐helix‐bundle protein.
Salmonella FliS does not show cooperative melting transition.
The native state of FliS exhibits molten globule‐like features.
Noncooperative unfolding suggests structural plasticity essential for function.
The differential diagnosis of patients with Disorder of Consciousness (DoC), in particular in the chronic phase, is significantly difficult. Actually, about 40% of patients with unresponsive ...wakefulness syndrome (UWS) and the minimally conscious state (MCS) are misdiagnosed. Indeed, only advanced paraclinical approaches, including advanced EEG analyses, can allow achieving a more reliable diagnosis, that is, discovering residual traces of awareness in patients with UWS (namely, functional Locked-In Syndrome (fLIS)). These approaches aim at capturing the residual brain network models, at rest or that may be activated in response to relevant stimuli, which may be appropriate for awareness to emerge (despite their insufficiency to generate purposeful motor behaviors). For this, different brain network models have been studied in patients with DoC by using sensory stimuli (i.e., passive tasks), probing response to commands (i.e., active tasks), and during resting-state. Since it can be difficult for patients with DoC to perform even simple active tasks, this scoping review aims at summarizing the current, innovative neurophysiological examination methods in resting state/passive modality to differentiate and prognosticate patients with DoC. We conclude that the electrophysiologically-based diagnostic procedures represent an important resource for diagnosis, prognosis, and, therefore, management of patients with DoC, using advance passive and resting state paradigm analyses for the patients who lie in the "greyzones" between MCS, UWS, and fLIS.
Growing research is focusing on the identification of markers predicting recovery and demonstrating covert awareness in patients with chronic disorders of consciousness (DOC). Herein, we describe the ...case of a woman who emerged from unresponsive wakefulness syndrome (UWS) after four years, in whom an experimental protocol assessing brain connectivity predicted her awareness recovery, indicating a functional locked-in syndrome (FLIS) diagnosis.
A 68-year-old woman was admitted to our institute in 2012 in a UWS secondary to a severe brain hemorrhage, with a Coma Recovery Scale-Revised score of five. Her clinical conditions were stable for about two years, despite the intensive neurorehabilitation treatment. During hospitalization, she underwent a neurophysiological protocol demonstrating an extensive nociceptive processing within the pain matrix. After 3 years, our subject emerged from UWS, and then from minimally conscious state, being able to communicate properly.
Approaches investigating brain connectivity may be useful in DOC diagnosis and prognosis, highlighting residual brain networks subtending covert awareness. Hence, our case supports the necessity of taking into account FLIS diagnosis in DOC differential diagnosis and implementing paraclinical follow-up to intercept cases of possible, late recovery of consciousness, thus optimizing the most appropriate management and rehabilitative setting.
Abstract
This article reviews knowledge derived from the introduction of the concept of in situ follicular lymphoma (FL). The following questions are addressed: (1) How should in situ lymphomas be ...defined and diagnosed? (2) Is in situ lymphoma an early step of lymphomagenesis? (3) Is the concept of early neoplasia applicable to the lymphoma setting? (4) How should patients with in situ lymphoma be managed? The commonly used term of in situ FL, also called FL in situ (FLIS), has been adopted to define a B-cell lymphoid neoplasia with an intrafollicular growth pattern. The neoplastic B cells are localized within the germinal center, without invasion of surrounding structures. Pathological diagnosis requires recognizing strong immunostaining of BCL2 and CD10 by neoplastic B cells inside the affected follicles. Fluorescence in situ hybridization (FISH) analysis for t(14;18) is mandatory in doubtful cases in which immunohistochemistry data are ambiguous. In situ FL is probably the earliest stage of development of FL, while the concept of "early" lymphoma is applicable when minimal disease extends beyond the boundaries of the follicular compartment. From a clinical point of view, in situ FL has an uncertain clinical behavior and unknown risk to progression to overt lymphoma. How to approach and monitor patients with in situ FL is currently uncertain. An asymptomatic patient with stage 1 in situ FL requires the same treatment plan as an asymptomatic patient with stage 1 conventional FL. For patients with concomitant overt malignancy, therapy must be applied according to the malignant counterpart.
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