Intracellular Dynamic Assembly of Deep‐Red Emitting Supramolecular Nanostructures Based on the Pt…Pt Metallophilic Interaction

AbstractThe dynamic assembly of the cell wall is key to the maintenance of cell shape during bacterial growth. Here, we present a method for the analysis of Escherichia coli cell wall growth at high spatial and temporal resolution, which is achieved by tracing the movement of fluorescently labeled cell wall-anchored flagellar motors. Using this method, we clearly identify the active and inert zones of cell wall growth during bacterial elongation. Within the active zone, the insertion of newly synthesized peptidoglycan occurs homogeneously in the axial direction without twisting of the cell body. Based on the measured parameters, we formulate a Bernoulli shift map model to predict the partitioning of cell wall-anchored proteins following cell division.

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Insight into the AcrAB-TolC Complex Assembly Process Learned from Competition Studies

Antibiotics ◽

10.3390/antibiotics10070830 ◽

2021 ◽

Vol 10 (7) ◽

pp. 830

Author(s):

Prasangi Rajapaksha ◽

Isoiza Ojo ◽

Ling Yang ◽

Ankit Pandeya ◽

Thilini Abeywansha ◽

...

Keyword(s):

Efflux Pump ◽

Dominant Negative ◽

Dominant Negative Effect ◽

Assembly Process ◽

Multidrug Efflux ◽

E Coli ◽

Multidrug Efflux Pumps ◽

Negative Effect ◽

Dynamic Assembly ◽

Pump Assembly

The RND family efflux pump AcrAB-TolC in E. coli and its homologs in other Gram-negative bacteria are major players in conferring multidrug resistance to the cells. While the structure of the pump complex has been elucidated with ever-increasing resolution through crystallography and Cryo-EM efforts, the dynamic assembly process remains poorly understood. Here, we tested the effect of overexpressing functionally defective pump components in wild type E. coli cells to probe the pump assembly process. Incorporation of a defective component is expected to reduce the efflux efficiency of the complex, leading to the so called “dominant negative” effect. Being one of the most intensively studied bacterial multidrug efflux pumps, many AcrA and AcrB mutations have been reported that disrupt efflux through different mechanisms. We examined five groups of AcrB and AcrA mutants, defective in different aspects of assembly and substrate efflux. We found that none of them demonstrated the expected dominant negative effect, even when expressed at concentrations many folds higher than their genomic counterpart. The assembly of the AcrAB-TolC complex appears to have a proof-read mechanism that effectively eliminated the formation of futile pump complex.

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Intracellular Dynamic Response Characteristics of Pineal Photoreceptors

Ophthalmic Research ◽

10.1159/000265305 ◽

1984 ◽

Vol 16 (1-2) ◽

pp. 119-122

Author(s):

Y. Morit ◽

K. Segi ◽

M. Samejima ◽

T. Nakamura

Keyword(s):

Dynamic Response ◽

Response Characteristics ◽

Dynamic Response Characteristics ◽

Pineal Photoreceptors ◽

Intracellular Dynamic

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The role of VPS4 in ESCRT-III polymer remodeling

Biochemical Society Transactions ◽

10.1042/bst20180026 ◽

2019 ◽

Vol 47 (1) ◽

pp. 441-448 ◽

Cited By ~ 8

Author(s):

Christophe Caillat ◽

Sourav Maity ◽

Nolwenn Miguet ◽

Wouter H. Roos ◽

Winfried Weissenhorn

Keyword(s):

Active Role ◽

Mechanistic Models ◽

Membrane Remodeling ◽

Filament Formation ◽

Enveloped Viruses ◽

Endosomal Sorting ◽

Membrane Fission ◽

Dynamic Assembly ◽

Inside Out

Abstract The endosomal sorting complex required for transport-III (ESCRT-III) and VPS4 catalyze a variety of membrane-remodeling processes in eukaryotes and archaea. Common to these processes is the dynamic recruitment of ESCRT-III proteins from the cytosol to the inner face of a membrane neck structure, their activation and filament formation inside or at the membrane neck and the subsequent or concomitant recruitment of the AAA-type ATPase VPS4. The dynamic assembly of ESCRT-III filaments and VPS4 on cellular membranes induces constriction of membrane necks with large diameters such as the cytokinetic midbody and necks with small diameters such as those of intraluminal vesicles or enveloped viruses. The two processes seem to use different sets of ESCRT-III filaments. Constriction is then thought to set the stage for membrane fission. Here, we review recent progress in understanding the structural transitions of ESCRT-III proteins required for filament formation, the functional role of VPS4 in dynamic ESCRT-III assembly and its active role in filament constriction. The recent data will be discussed in the context of different mechanistic models for inside-out membrane fission.

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TCP Window Based Dynamic Assembly Period in Optical Burst Switching Network

2007 IEEE International Conference on Communications ◽

10.1109/icc.2007.397 ◽

2007 ◽

Cited By ~ 2

Author(s):

S. Peng ◽

Z. Li ◽

X. Wu ◽

A. Xu

Keyword(s):

Optical Burst Switching ◽

Switching Network ◽

Burst Switching ◽

Dynamic Assembly ◽

Optical Burst Switching Network ◽

Optical Burst

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TCP Window-Based Flow-Oriented Dynamic Assembly Algorithm for OBS Networks

Journal of Lightwave Technology ◽

10.1109/jlt.2008.927756 ◽

2009 ◽

Vol 27 (6) ◽

pp. 670-678 ◽

Cited By ~ 7

Author(s):

Shuping Peng ◽

Zhengbin Li ◽

Yongqi He ◽

Anshi Xu

Keyword(s):

Assembly Algorithm ◽

Dynamic Assembly

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The intracellular dynamic of protein palmitoylation

The Journal of Cell Biology ◽

10.1083/jcb.201008160 ◽

2010 ◽

Vol 191 (7) ◽

pp. 1229-1238 ◽

Cited By ~ 198

Author(s):

Christine Salaun ◽

Jennifer Greaves ◽

Luke H. Chamberlain

Keyword(s):

Posttranslational Modifications ◽

Posttranslational Modification ◽

Mammalian Cells ◽

Protein Functionality ◽

Peripheral Membrane Proteins ◽

Protein Palmitoylation ◽

Thioester Bond ◽

Intracellular Sorting ◽

Intracellular Dynamic ◽

Insight Into

S-palmitoylation describes the reversible attachment of fatty acids (predominantly palmitate) onto cysteine residues via a labile thioester bond. This posttranslational modification impacts protein functionality by regulating membrane interactions, intracellular sorting, stability, and membrane micropatterning. Several recent findings have provided a tantalizing insight into the regulation and spatiotemporal dynamics of protein palmitoylation. In mammalian cells, the Golgi has emerged as a possible super-reaction center for the palmitoylation of peripheral membrane proteins, whereas palmitoylation reactions on post-Golgi compartments contribute to the regulation of specific substrates. In addition to palmitoylating and depalmitoylating enzymes, intracellular palmitoylation dynamics may also be controlled through interplay with distinct posttranslational modifications, such as phosphorylation and nitrosylation.

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