Browse
Submit Data
Databases
API
Help

Dataset Information

21 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Tight coupling between nucleus and cell migration through the perinuclear actin cap.

ABSTRACT: Although eukaryotic cells are known to alternate between 'advancing' episodes of fast and persistent movement and 'hesitation' episodes of low speed and low persistence, the molecular mechanism that controls the dynamic changes in morphology, speed and persistence of eukaryotic migratory cells remains unclear. Here, we show that the movement of the interphase nucleus during random cell migration switches intermittently between two distinct modes - rotation and translocation - that follow with high fidelity the sequential rounded and elongated morphologies of the nucleus and cell body, respectively. Nuclear rotation and translocation mediate the stop-and-go motion of the cell through the dynamic formation and dissolution, respectively, of the contractile perinuclear actin cap, which is dynamically coupled to the nuclear lamina and the nuclear envelope through LINC complexes. A persistent cell movement and nuclear translocation driven by the actin cap are halted following the disruption of the actin cap, which in turn allows the cell to repolarize for its next persistent move owing to nuclear rotation mediated by cytoplasmic dynein light intermediate chain 2.

SUBMITTER: Kim DH

PROVIDER: S-EPMC4038945 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Coupling of Perinuclear Actin Cap and Nuclear Mechanics in Regulating Flow-Induced Yap Spatiotemporal Nucleocytoplasmic Transport.

Project description:Mechanical forces, including flow shear stress, govern fundamental cellular processes by modulating nucleocytoplasmic transport of transcription factors like Yes-associated Protein (YAP). However, the underlying mechanical mechanism remains elusive. In this study, it is reported that unidirectional flow induces biphasic YAP transport with initial nuclear import, followed by nuclear export as actin cap formation and nuclear stiffening. Conversely, pathological oscillatory flow induces slight actin cap formation, nuclear softening, and sustained YAP nuclear localization. To elucidate the disparately YAP spatiotemporal distribution, a 3D mechanochemical model is developed, which integrates flow sensing, cytoskeleton organization, nucleus mechanotransduction, and YAP transport. The results unveiled that despite the significant localized nuclear stress imposed by the actin cap, its inherent stiffness counteracts the dispersed contractile stress exerted by conventional fibers on the nuclear membrane. Moreover, alterations in nuclear stiffness synergistically regulate nuclear deformation, thereby governing YAP transport. Furthermore, by expanding the single-cell model to a collective vertex framework, it is revealed that the irregularities in actin cap formation within individual cells have the potential to induce topological defects and spatially heterogeneous YAP distribution in the cellular monolayer. This work unveils a unified mechanism of flow-induced nucleocytoplasmic transport, providing a linkage between transcription factor localization and mechanical stimulation.

| S-EPMC10953556 | biostudies-literature

Perinuclear Arp2/3-driven actin polymerization enables nuclear deformation to facilitate cell migration through complex environments.

Project description:Cell migration has two opposite faces: although necessary for physiological processes such as immune responses, it can also have detrimental effects by enabling metastatic cells to invade new organs. In vivo, migration occurs in complex environments and often requires a high cellular deformability, a property limited by the cell nucleus. Here we show that dendritic cells, the sentinels of the immune system, possess a mechanism to pass through micrometric constrictions. This mechanism is based on a rapid Arp2/3-dependent actin nucleation around the nucleus that disrupts the nuclear lamina, the main structure limiting nuclear deformability. The cells' requirement for Arp2/3 to pass through constrictions can be relieved when nuclear stiffness is decreased by suppressing lamin A/C expression. We propose a new role for Arp2/3 in three-dimensional cell migration, allowing fast-moving cells such as leukocytes to rapidly and efficiently migrate through narrow gaps, a process probably important for their function.

| S-EPMC4796365 | biostudies-literature

Increased Lamin B1 Levels Promote Cell Migration by Altering Perinuclear Actin Organization.

Project description:Cell migration requires reposition and reshaping of the cell nucleus. The nuclear lamina is highly important for migration of both primary and cancer cells. B-type lamins are important for proper migration of epicardial cells and neurons and increased lamin B to lamin A ratio accelerates cancer cell migration through confined spaces. Moreover, a positive association between lamin B1 levels and tumor formation and progression is found in various cancer types. Still, the molecular mechanism by which B-type lamins promote cell migration is not fully understood. To better understand this mechanism, we tested the effects of lamin B1 on perinuclear actin organization. Here we show that induction of melanoma cell migration leads to the formation of a cytosolic Linker of Nucleoskeleton and Cytoskeleton (LINC) complex-independent perinuclear actin rim, which has not been detected in migrating cells, yet. Significantly, increasing the levels of lamin B1 but not the levels of lamin A prevented perinuclear actin rim formation while accelerated the cellular migration rate. To interfere with the perinuclear actin rim, we generated a chimeric protein that is localized to the outer nuclear membrane and cleaves perinuclear actin filaments in a specific manner without disrupting other cytosolic actin filaments. Using this tool, we found that disruption of the perinuclear actin rim accelerated the cellular migration rate in a similar manner to lamin B1 over-expression. Taken together, our results suggest that increased lamin B1 levels can accelerate cell migration by inhibiting the association of the nuclear envelope with actin filaments that may reduce nuclear movement and deformability.

| S-EPMC7598699 | biostudies-literature

Aberrant MET activation impairs perinuclear actin cap organization with YAP1 cytosolic relocation.

Project description:Little is known about the signaling network responsible for the organization of the perinuclear actin cap, a recently identified structure holding unique roles in the regulation of nuclear shape and cell directionality. In cancer cells expressing a constitutively active MET, we show a rearrangement of the actin cap filaments, which crash into perinuclear patches associated with spherical nuclei, meandering cell motility and inactivation of the mechano-transducer YAP1. MET ablation is sufficient to reactivate YAP1 and restore the cap, leading to enhanced directionality and flattened nuclei. Consistently, the introduction of a hyperactive MET in normal epithelial cells, enhances nuclear height and alters the cap organization, as also confirmed by TEM analysis. Finally, the constitutively active YAP1 mutant YAP5SA is able to overcome the effects of oncogenic MET. Overall, our work describes a signaling axis empowering MET-mediated YAP1 dampening and actin cap misalignment, with implications for nuclear shape and cell motility.

| S-EPMC10576810 | biostudies-literature

Gβ Regulates Coupling between Actin Oscillators for Cell Polarity and Directional Migration.

Project description:For directional movement, eukaryotic cells depend on the proper organization of their actin cytoskeleton. This engine of motility is made up of highly dynamic nonequilibrium actin structures such as flashes, oscillations, and traveling waves. In Dictyostelium, oscillatory actin foci interact with signals such as Ras and phosphatidylinositol 3,4,5-trisphosphate (PIP3) to form protrusions. However, how signaling cues tame actin dynamics to produce a pseudopod and guide cellular motility is a critical open question in eukaryotic chemotaxis. Here, we demonstrate that the strength of coupling between individual actin oscillators controls cell polarization and directional movement. We implement an inducible sequestration system to inactivate the heterotrimeric G protein subunit Gβ and find that this acute perturbation triggers persistent, high-amplitude cortical oscillations of F-actin. Actin oscillators that are normally weakly coupled to one another in wild-type cells become strongly synchronized following acute inactivation of Gβ. This global coupling impairs sensing of internal cues during spontaneous polarization and sensing of external cues during directional motility. A simple mathematical model of coupled actin oscillators reveals the importance of appropriate coupling strength for chemotaxis: moderate coupling can increase sensitivity to noisy inputs. Taken together, our data suggest that Gβ regulates the strength of coupling between actin oscillators for efficient polarity and directional migration. As these observations are only possible following acute inhibition of Gβ and are masked by slow compensation in genetic knockouts, our work also shows that acute loss-of-function approaches can complement and extend the reach of classical genetics in Dictyostelium and likely other systems as well.

| S-EPMC4758609 | biostudies-literature

STEF/TIAM2-mediated Rac1 activity at the nuclear envelope regulates the perinuclear actin cap.

Project description:The perinuclear actin cap is an important cytoskeletal structure that regulates nuclear morphology and re-orientation during front-rear polarisation. The mechanisms regulating the actin cap are currently poorly understood. Here, we demonstrate that STEF/TIAM2, a Rac1 selective guanine nucleotide exchange factor, localises at the nuclear envelope, co-localising with the key perinuclear proteins Nesprin-2G and Non-muscle myosin IIB (NMMIIB), where it regulates perinuclear Rac1 activity. We show that STEF depletion reduces apical perinuclear actin cables (a phenotype rescued by targeting active Rac1 to the nuclear envelope), increases nuclear height and impairs nuclear re-orientation. STEF down-regulation also reduces perinuclear pMLC and decreases myosin-generated tension at the nuclear envelope, suggesting that STEF-mediated Rac1 activity regulates NMMIIB activity to promote stabilisation of the perinuclear actin cap. Finally, STEF depletion decreases nuclear stiffness and reduces expression of TAZ-regulated genes, indicating an alteration in mechanosensing pathways as a consequence of disruption of the actin cap.

| S-EPMC5974301 | biostudies-literature

The differential formation of the LINC-mediated perinuclear actin cap in pluripotent and somatic cells.

Project description:The actin filament cytoskeleton mediates cell motility and adhesion in somatic cells. However, whether the function and organization of the actin network are fundamentally different in pluripotent stem cells is unknown. Here we show that while conventional actin stress fibers at the basal surface of cells are present before and after onset of differentiation of mouse (mESCs) and human embryonic stem cells (hESCs), actin stress fibers of the actin cap, which wrap around the nucleus, are completely absent from undifferentiated mESCs and hESCs and their formation strongly correlates with differentiation. Similarly, the perinuclear actin cap is absent from human induced pluripotent stem cells (hiPSCs), while it is organized in the parental lung fibroblasts from which these hiPSCs are derived and in a wide range of human somatic cells, including lung, embryonic, and foreskin fibroblasts and endothelial cells. During differentiation, the formation of the actin cap follows the expression and proper localization of nuclear lamin A/C and associated linkers of nucleus and cytoskeleton (LINC) complexes at the nuclear envelope, which physically couple the actin cap to the apical surface of the nucleus. The differentiation of hESCs is accompanied by the progressive formation of a perinuclear actin cap while induced pluripotency is accompanied by the specific elimination of the actin cap, and that, through lamin A/C and LINC complexes, this actin cap is involved in progressively shaping the nucleus of hESCs undergoing differentiation. While, the localization of lamin A/C at the nuclear envelope is required for perinuclear actin cap formation, it is not sufficient to control nuclear shape.

| S-EPMC3344930 | biostudies-literature

FMN2 Makes Perinuclear Actin to Protect Nuclei during Confined Migration and Promote Metastasis.

Project description:Cell migration in confined 3D tissue microenvironments is critical for both normal physiological functions and dissemination of tumor cells. We discovered a cytoskeletal structure that prevents damage to the nucleus during migration in confined microenvironments. The formin-family actin filament nucleator FMN2 associates with and generates a perinuclear actin/focal adhesion (FA) system that is distinct from previously characterized actin/FA structures. This system controls nuclear shape and positioning in cells migrating on 2D surfaces. In confined 3D microenvironments, FMN2 promotes cell survival by limiting nuclear envelope damage and DNA double-strand breaks. We found that FMN2 is upregulated in human melanomas and showed that disruption of FMN2 in mouse melanoma cells inhibits their extravasation and metastasis to the lung. Our results indicate a critical role for FMN2 in generating a perinuclear actin/FA system that protects the nucleus and DNA from damage to promote cell survival during confined migration and thus promote cancer metastasis.

| S-EPMC5135586 | biostudies-literature

The LINC-anchored actin cap connects the extracellular milieu to the nucleus for ultrafast mechanotransduction.

Project description:Cells continuously sense and respond to external mechanical forces through their cytoskeleton. Here we show that only a small subset of actin fibers, those forming the perinuclear actin cap that wraps around the nucleus, form in response to low physiological mechanical stresses in adherent fibroblasts. While conventional basal stress fibers form only past a threshold shear stress of 0.5 dyn/cm(2), actin-cap fibers are formed at shear stresses 50 times lower and orders-of-magnitude faster than biochemical stimulation. This fast differential response is uniquely mediated by focal adhesion protein zyxin at low shear stress and actomyosin fibers of the actin cap. We identify additional roles for lamin A/C of the nuclear lamina and linkers of nucleus to cytoskeleton (LINC) molecules nesprin2giant and nesprin3, which anchor actin cap fibers to the nucleus. These results suggest an interconnected physical pathway for mechanotransduction, from the extracellular milieu to the nucleus.

| S-EPMC3548190 | biostudies-literature

Germ cell migration across Sertoli cell tight junctions.

Project description:The blood-testis barrier includes strands of tight junctions between somatic Sertoli cells that restricts solutes from crossing the paracellular space, creating a microenvironment within seminiferous tubules and providing immune privilege to meiotic and postmeiotic cells. Large cysts of germ cells transit the Sertoli cell tight junctions (SCTJs) without compromising their integrity. We used confocal microscopy to visualize SCTJ components during germ cell cyst migration across the SCTJs. Cysts become enclosed within a network of transient compartments fully bounded by old and new tight junctions. Dissolution of the old tight junctions releases the germ cells into the adluminal compartment, thus completing transit across the blood-testis barrier. Claudin 3, a tight junction protein, is transiently incorporated into new tight junctions and then replaced by claudin 11.

| S-EPMC3694388 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data