Tracer dynamics in one dimensional gases of active or passive particles DOI Creative Commons
Tirthankar Banerjee, Robert L. Jack, M. E. Cates

et al.

Journal of Statistical Mechanics Theory and Experiment, Journal Year: 2022, Volume and Issue: 2022(1), P. 013209 - 013209

Published: Jan. 1, 2022

We consider one-dimensional systems comprising either active run-and-tumble particles (RTPs) or passive Brownian random walkers. These are noninteracting have hardcore exclusions. study the dynamics of a single tracer particle embedded in such system - this may be passive, with exclusion from environmental particles. In an environment, both and tracers show long-time subdiffusion: displacements scale as $t^{1/4}$ density-dependent prefactor that is independent type, differs corresponding result for passive-in-passive subdiffusion. environment particles, results recovered at low densities tracers, but transient caging effects slow motion higher densities, delaying onset any regime. For we find more complex outcomes, which depend on details dynamical discretization scheme. interpret these by studying density distribution around tracer. particular, sticking to cause it move slowly than interacting environments, while anomalous behaviour active-in-passive cases stems `snowplough' effect whereby large pile diffusive accumulates front RTP during ballistic run.

Language: Английский

CSPP1 stabilizes growing microtubule ends and damaged lattices from the luminal side DOI Creative Commons
Cyntha M. van den Berg, Vladimir A. Volkov, Sebastian Schnorrenberg

et al.

The Journal of Cell Biology, Journal Year: 2023, Volume and Issue: 222(4)

Published: Feb. 8, 2023

Microtubules are dynamic cytoskeletal polymers, and their organization stability tightly regulated by numerous cellular factors. While regulatory proteins controlling the formation of interphase microtubule arrays mitotic spindles have been extensively studied, biochemical mechanisms responsible for generating stable cores centrioles cilia poorly understood. Here, we used in vitro reconstitution assays to investigate microtubule-stabilizing properties CSPP1, a centrosome cilia-associated protein mutated neurodevelopmental ciliopathy Joubert syndrome. We found that CSPP1 preferentially binds polymerizing ends grow slowly or undergo growth perturbations and, this way, resembles compounds such as taxanes. Fluorescence microscopy cryo-electron tomography showed is deposited lumen inhibits shortening through two separate domains. also specifically recognizes stabilizes damaged lattices. These data help explain how regulates elongation ciliary axonemes other microtubule-based structures.

Language: Английский

Citations

24
Metabolic regulation of cytoskeleton functions by HDAC6-catalyzed α-tubulin lactylation DOI Creative Commons

Shuangshuang Sun,

Zhe Xu, Liying He

et al.

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: Sept. 27, 2024

Language: Английский

Citations

12
Sustained rhoptry docking and discharge requires Toxoplasma gondii intraconoidal microtubule-associated proteins DOI Creative Commons
Nicolas Dos Santos Pacheco, Albert Tell i Puig, Amandine Guérin

et al.

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: Jan. 9, 2024

Abstract In Apicomplexa, rhoptry discharge is essential for invasion and involves an apical vesicle (AV) docking one or two rhoptries to a macromolecular secretory apparatus. Toxoplasma gondii armed with 10–12 5-6 microtubule-associated vesicles (MVs) presumably iterative discharge. Here, we have addressed the localization functional significance of intraconoidal microtubule (ICMT)-associated proteins instrumental invasion. Mechanistically, depletion ICMAP2 leads dissociation ICMTs, their detachment from conoid dispersion MVs rhoptries. ICMAP3 exists in isoforms that contribute control ICMTs length at AV, respectively. This study illuminates central role play scaffolding multiple process virulence mouse model infection addition promotes sterile protection against T. via release key effectors inducing immunity.

Language: Английский

Citations

11
Endothelial cytoskeleton in mechanotransduction and vascular diseases DOI

Linlu Jin,

Yixue Qin,

Yili Zhao

et al.

Journal of Biomechanics, Journal Year: 2025, Volume and Issue: 182, P. 112579 - 112579

Published: Feb. 9, 2025

Language: Английский

Citations

1
Vimentin undergoes liquid–liquid phase separation to form droplets which wet and stabilize actin fibers DOI Creative Commons
Arkaprabha Basu,

Tommy J. Krug,

Benjamin du Pont

et al.

Proceedings of the National Academy of Sciences, Journal Year: 2025, Volume and Issue: 122(10)

Published: March 3, 2025

The cytoskeleton is composed of F-actin, microtubules, and intermediate filaments (IFs). Vimentin one the most ubiquitous well-studied IFs. It involved in many activities including wound healing, tissue fibrosis, cancer metastasis, all which require rapid vimentin IF assembly. In this paper, we report that forms liquid condensates appear to enable filament growth. Given transient nature these droplets, focus on properties vimentin-Y117L, has a point mutation leads formation but not IFs, enabling us study droplets detail. dissolve under 1,6-Hexanediol treatment decreasing concentration, confirming they are liquid, phase separated. These extensively wet actin stress fibers, rendering them resistant actin-binding drugs protecting from depolymerization. We show similar behavior occurs wild-type during its assembly into filaments.

Language: Английский

Citations

1
Visualising the cytoskeletal machinery in neuronal growth cones using cryo-electron tomography DOI Creative Commons
Joseph Atherton, Melissa A. Stouffer, Fiona Francis

et al.

Journal of Cell Science, Journal Year: 2022, Volume and Issue: 135(7)

Published: April 1, 2022

Neurons extend axons to form the complex circuitry of mature brain. This depends on coordinated response and continuous remodelling microtubule F-actin networks in axonal growth cone. Growth cone architecture remains poorly understood at nanoscales. We therefore investigated mouse hippocampal neuron cones using cryo-electron tomography directly visualise their three-dimensional subcellular with molecular detail. Our data showed that hexagonal arrays actin bundles filopodia penetrate terminate deep within interior. observed modulation these other by alteration individual helical structures. Microtubules blunt, slightly flared or gently curved ends predominated cone, frequently contained lumenal particles exhibited lattice defects. Investigation effect absence doublecortin, a neurodevelopmental cytoskeleton regulator, no major anomalies overall organisation subpopulations. However, our suggested microtubules sustained more structural defects, highlighting importance integrity during migration.

Language: Английский

Citations

31
Mechanism of ribosome-associated mRNA degradation during tubulin autoregulation DOI Creative Commons
Markus Höpfler, Eva Absmeier,

Sew‐Yeu Peak‐Chew

et al.

Molecular Cell, Journal Year: 2023, Volume and Issue: 83(13), P. 2290 - 2302.e13

Published: June 8, 2023

Microtubules play crucial roles in cellular architecture, intracellular transport, and mitosis. The availability of free tubulin subunits affects polymerization dynamics microtubule function. When cells sense excess tubulin, they trigger degradation the encoding mRNAs, which requires recognition nascent polypeptide by tubulin-specific ribosome-binding factor TTC5. How TTC5 initiates decay mRNAs is unknown. Here, our biochemical structural analysis reveals that recruits poorly studied protein SCAPER to ribosome. SCAPER, turn, engages CCR4-NOT deadenylase complex through its CNOT11 subunit mRNA decay. mutants cause intellectual disability retinitis pigmentosa humans are impaired recruitment, degradation, microtubule-dependent chromosome segregation. Our findings demonstrate how a on ribosome physically linked factors via relay protein-protein interactions, providing paradigm for specificity cytoplasmic gene regulation.

Language: Английский

Citations

21
Microtubules and Cell Division: Potential Pharmacological Targets in Cancer Therapy DOI

Jomon Sebastian,

Krishnan Rathinasamy

Current Drug Targets, Journal Year: 2023, Volume and Issue: 24(11), P. 889 - 918

Published: July 31, 2023

Microtubules are a well-known target in cancer chemotherapy because of their critical role cell division. Chromosome segregation during mitosis depends on the establishment mitotic spindle apparatus through microtubule dynamics. The disruption dynamics stabilization or destabilization microtubules results arrest cells. Microtubule-targeted drugs, which interfere with dynamics, inhibit growth cells at phase and induce apoptotic death. principle microtubule-targeted drugs is to reduce disease unchecked proliferation. Many anti-microtubule agents produce significant inhibition widely used as chemotherapeutic for treatment cancer. that interact generally bind one three sites vinblastine site, taxol colchicine site. Colchicine binds interface tubulin heterodimer induces depolymerization microtubules. binding site much sought-after history drug discovery. colchicine-binding inhibitors have been discovered, but use limited due dose-limiting toxicity resistance humans. Combination therapy can be new strategy overcome these drawbacks currently available anticancer drugs. This review discusses significance potential pharmacological stresses necessity finding fight disease.

Language: Английский

Citations

21
CLASP2 recognizes tubulins exposed at the microtubule plus-end in a nucleotide state–sensitive manner DOI Creative Commons
Wangxi Luo, Vladimir Demidov, Qi Shen

et al.

Science Advances, Journal Year: 2023, Volume and Issue: 9(1)

Published: Jan. 4, 2023

CLASPs (cytoplasmic linker-associated proteins) are ubiquitous stabilizers of microtubule dynamics, but their molecular targets at the plus-end not understood. Using DNA origami-based reconstructions, we show that clusters human CLASP2 form a load-bearing bond with terminal non-GTP tubulins stabilized tip. This activity relies on unconventional TOG2 domain CLASP2, which releases its high-affinity dimers upon conversion into polymerization-competent GTP-tubulins. The ability to recognize nucleotide-specific tubulin conformation and stabilize catastrophe-promoting intertwines previously underappreciated exchange between GDP GTP tubulins. We propose TOG2-dependent stabilization sporadically occurring represents distinct mechanism suppress catastrophe freely assembling ends promote persistent assembly tethered ends, such as kinetochores in dividing cells.

Language: Английский

Citations

19
Structural insights into the mechanism of GTP initiation of microtubule assembly DOI Creative Commons
Ju Zhou, Anhui Wang,

Yinlong Song

et al.

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: Sept. 25, 2023

Abstract In eukaryotes, the dynamic assembly of microtubules (MT) plays an important role in numerous cellular processes. The underlying mechanism GTP triggering MT is still unknown. Here, we present cryo-EM structures tubulin heterodimer at their GTP- and GDP-bound states, intermediate states GTP-tubulin, final stages MT. Both GDP-tubulin heterodimers adopt similar curved conformations with subtle flexibility differences. head-to-tail oligomers heterodimers, inter-dimer interface exhibits greater flexibility, particularly tangential bending. Cryo-EM reveals two types lateral contacts, “Tube-bond” “MT-bond”. Further, molecular dynamics (MD) simulations show that triggers contact formation multiple sequential steps, gradually straightening heterodimers. Therefore, propose a flexible model GTP-initiated assembly, including longitudinal to explain nucleation

Language: Английский

Citations

18