Browse
Submit Data
Databases
API
Help

Dataset Information

23 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Lasp-1 regulates podosome function.

ABSTRACT: Eukaryotic cells form a variety of adhesive structures to connect with their environment and to regulate cell motility. In contrast to classical focal adhesions, podosomes, highly dynamic structures of different cell types, are actively engaged in matrix remodelling and degradation. Podosomes are composed of an actin-rich core region surrounded by a ring-like structure containing signalling molecules, motor proteins as well as cytoskeleton-associated proteins. Lasp-1 is a ubiquitously expressed, actin-binding protein that is known to regulate cytoskeleton architecture and cell migration. This multidomain protein is predominantely present at focal adhesions, however, a second pool of Lasp-1 molecules is also found at lamellipodia and vesicle-like microdomains in the cytosol.In this report, we show that Lasp-1 is a novel component and regulator of podosomes. Immunofluorescence studies reveal a localization of Lasp-1 in the podosome ring structure, where it colocalizes with zyxin and vinculin. Life cell imaging experiments demonstrate that Lasp-1 is recruited in early steps of podosome assembly. A siRNA-mediated Lasp-1 knockdown in human macrophages affects podosome dynamics as well as their matrix degradation capacity. In summary, our data indicate that Lasp-1 is a novel component of podosomes and is involved in the regulation of podosomal function.

SUBMITTER: Stolting M

PROVIDER: S-EPMC3325968 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

The matricellular protein CCN5 regulates podosome function via interaction with integrin ?v? 3.

Project description:CCN proteins play crucial roles in cell motility, matrix turnover, and proliferation. In particular, CCN5 plays a role in cell motility and proliferation in several cell types; however, no functional binding proteins for CCN5 have been identified. In this study we report that CCN5 binds to the cell surface receptor integrin ?v?3 in vascular smooth muscle cells. Furthermore, this interaction takes place in podosomes, organelles known to degrade matrix and mediate motility. We show that CCN5 regulates the ability of podosomes to degrade matrix, but does not affect podosome formation. The level of CCN5 present in a podosome negatively correlates with its ability to degrade matrix. Conversely, knockdown of CCN5 greatly enhances the matrix-degrading ability of podosomes. These findings suggest that the antimotility effects of CCN5 may be mediated through the direct interaction of CCN5 and integrin ?v?3 in podosomes and the concomitant suppression of matrix degradation that is required for cell migration.

| S-EPMC4063992 | biostudies-literature

The podosome marker protein Tks5 regulates macrophage invasive behavior.

Project description:Tks5 is a Src substrate and adaptor protein previously recognized for its regulation of cancer cell invasion through modulation of specialized adhesion structures called podosomes/invadopodia. Here we show for the first time that Tks5 localizes to the podosomes of primary macrophages, and that Tks5 protein levels increase concurrently with podosome deposition during the differentiation of monocytes into macrophages. Similar results are reported for model THP-1 cells, which differentiate into macrophages and form proteolytically active podosomes in response to a PKC signaling agonist (PMA) and with sensitivity to a PKC inhibitor (bisindolylmaleimide). Genetic manipulation of Tks5 expression (silencing and overexpression) in stable THP-1 cell lines does not independently alter this macrophage differentiation process. Nor do these cells lose the ability to focalize F-actin and its accessory proteins into podosome-like structures following PMA treatment. However, Tks5 directly controls podosome-associated gelatin degradation and invasion through collective changes in adhesion, chemotaxis, and the expression/proteolytic activity of MMP9. The Src family kinase-dependent phosphorylation of Tks5 is also implicated in the regulation of THP-1 macrophage invasive behavior. These results therefore define a previously unappreciated function of Tks5 signaling specific to the functional attributes of the macrophage podosome in adhesion, motility, and extracellular matrix-remodeling.

| S-EPMC3240724 | biostudies-literature

A kindlin-3-leupaxin-paxillin signaling pathway regulates podosome stability.

Project description:Binding of kindlins to integrins is required for integrin activation, stable ligand binding, and subsequent intracellular signaling. How hematopoietic kindlin-3 contributes to the assembly and stability of the adhesion complex is not known. Here we report that kindlin-3 recruits leupaxin into podosomes and thereby regulates paxillin phosphorylation and podosome turnover. We demonstrate that the activity of the protein tyrosine phosphatase PTP-PEST, which controls paxillin phosphorylation, requires leupaxin. In contrast, despite sharing the same binding mode with leupaxin, paxillin recruitment into podosomes is kindlin-3 independent. Instead, we found paxillin together with talin and vinculin in initial adhesion patches of kindlin-3-null cells. Surprisingly, despite its presence in these early adhesion patches, podosomes can form in the absence of paxillin or any paxillin member. In conclusion, our findings show that kindlin-3 not only activates and clusters integrins into podosomes but also regulates their lifetime by recruiting leupaxin, which controls PTP-PEST activity and thereby paxillin phosphorylation and downstream signaling.

| S-EPMC6781449 | biostudies-literature

The nebulin repeat protein Lasp regulates I-band architecture and filament spacing in myofibrils.

Project description:Mutations in nebulin, a giant muscle protein with 185 actin-binding nebulin repeats, are the major cause of nemaline myopathy in humans. Nebulin sets actin thin filament length in sarcomeres, potentially by stabilizing thin filaments in the I-band, where nebulin and thin filaments coalign. However, the precise role of nebulin in setting thin filament length and its other functions in regulating power output are unknown. Here, we show that Lasp, the only member of the nebulin family in Drosophila melanogaster, acts at two distinct sites in the sarcomere and controls thin filament length with just two nebulin repeats. We found that Lasp localizes to the Z-disc edges to control I-band architecture and also localizes at the A-band, where it interacts with both actin and myosin to set proper filament spacing. Furthermore, introducing a single amino acid change into the two nebulin repeats of Lasp demonstrated different roles for each domain and established Lasp as a suitable system for studying nebulin repeat function.

| S-EPMC4137052 | biostudies-literature

Integrin linked kinase (ILK) regulates podosome maturation and stability in dendritic cells.

Project description:Podosomes are integrin-based adhesions fundamental for stabilisation of the leading lamellae in migrating dendritic cells (DCs) and for extracellular matrix (ECM) degradation. We have previously shown that soluble factors and chemokines such as SDF 1-a trigger podosome initiation whereas integrin ligands promote podosome maturation and stability in DCs. The exact intracellular signalling pathways that regulate the sequential organisation of podosomal components in response to extracellular cues remain largely undetermined. The Wiskott Aldrich Syndrome Protein (WASP) mediates actin polymerisation and the initial recruitment of integrins and associated proteins in a circular configuration surrounding the core of filamentous actin (F-actin) during podosome initiation. We have now identified integrin linked kinase (ILK) surrounding the podosomal actin core. We report that DC polarisation in response to chemokines and the assembly of actin cores during podosome initiation require PI3K-dependent clustering of the Wiskott Aldrich Syndrome Protein (WASP) in puncta independently of ILK. ILK is essential for the clustering of integrins and associated proteins leading to podosome maturation and stability that are required for degradation of the subjacent extracellular matrix and the invasive motility of DCs across connective tissue barriers. We conclude that WASP regulates DCs polarisation for migration and initiation of actin polymerisation downstream of PI3K in nascent podosomes. Subsequently, ILK mediates the accumulation of integrin-associated proteins during podosome maturation and stability for efficient degradation of the subjacent ECM during the invasive migration of DCs.

| S-EPMC3998073 | biostudies-literature

Podosome formation impairs endothelial barrier function by sequestering zonula occludens proteins.

Project description:Podosomes and tight junctions (TJs) are subcellular compartments that both exist in endothelial cells and localize at cell surfaces. In contrast to the well-characterized role of TJs in maintaining cerebrovascular integrity, the specific function of endothelial podosomes remains unknown. Intriguingly, we discovered cross-talk between podosomes and TJs in human brain endothelial cells. Tight junction scaffold proteins ZO-1 and ZO-2 localize at podosomes in response to phorbol-12-myristate-13-acetate treatment. We found that both ZO proteins are essential for podosome formation and function. Rather than being derived from new protein synthesis, podosomal ZO-1 and ZO-2 are relocated from a pre-existing pool found at the peripheral plasma membrane with enhanced physical interaction with cortactin, a known protein marker for podosomes. Sequestration of ZO proteins in podosomes weakens tight junction complex formation, leading to increased endothelial cell permeability. This effect can be further attenuated by podosome inhibitor PP2. Altogether, our data revealed a novel cellular function of podosomes, specifically, their ability to negatively regulate tight junction and endothelial barrier integrity, which have been linked to a variety of cerebrovascular diseases.

| S-EPMC7087352 | biostudies-literature

TSC1 regulates osteoclast podosome organization and bone resorption through mTORC1 and Rac1/Cdc42.

Project description:Reorganization of the podosome into the sealing zone is crucial for osteoclasts (OCLs) to resorb bone, but the underlying mechanisms are unclear. Here, we show that tuberous sclerosis complex 1 (TSC1) functions centrally in OCLs to promote podosome organization and bone resorption through mechanistic target of rapamycin complex 1 (mTORC1) and the small GTPases Rac1/Cdc42. During osteoclastogenesis, enhanced expression of TSC1 downregulates mTORC1 activity. TSC1 deletion in OCLs reduced podosome belt formation in vitro and sealing zone formation in vivo, leading to bone resorption deficiency and osteopetrosis. Mechanistically, TSC1 promoted podosome superstructure assembly by releasing mTORC1-dependent negative feedback inhibition of Rac1/Cdc42. Rapamycin and active Rac1/Cdc42 restore podosome organization and bone resorption and alleviate osteopetrotic phenotypes in mutant mice. Our findings reveal an essential role of TSC1 signaling in the regulation of bone resorption. Targeting TSC1 represents a novel strategy to inhibit bone resorption and prevent bone loss-related diseases.

| S-EPMC6143527 | biostudies-literature

Protein tyrosine phosphatase epsilon regulates integrin-mediated podosome stability in osteoclasts by activating Src.

Project description:The nonreceptor isoform of tyrosine phosphatase epsilon (cyt-PTPe) supports osteoclast adhesion and activity in vivo, leading to increased bone mass in female mice lacking PTPe (EKO mice). The structure and organization of the podosomal adhesion structures of EKO osteoclasts are abnormal; the molecular mechanism behind this is unknown. We show here that EKO podosomes are disorganized, unusually stable, and reorganize poorly in response to physical contact. Phosphorylation and activities of Src, Pyk2, and Rac are decreased and Rho activity is increased in EKO osteoclasts, suggesting that integrin signaling is defective in these cells. Integrin activation regulates cyt-PTPe by inducing Src-dependent phosphorylation of cyt-PTPe at Y638. This phosphorylation event is crucial because wild-type-but not Y638F-cyt-PTPe binds and further activates Src and restores normal stability to podosomes in EKO osteoclasts. Increasing Src activity or inhibiting Rho or its downstream effector Rho kinase in EKO osteoclasts rescues their podosomal stability phenotype, indicating that cyt-PTPe affects podosome stability by functioning upstream of these molecules. We conclude that cyt-PTPe participates in a feedback loop that ensures proper Src activation downstream of integrins, thus linking integrin signaling with Src activation and accurate organization and stability of podosomes in osteoclasts.

| S-EPMC2762143 | biostudies-other

STIM1-dependent Ca<sup>2+</sup> signaling regulates podosome formation to facilitate cancer cell invasion.

Project description:The clinical significance of STIM proteins and Orai Ca2+ channels in tumor progression has been demonstrated in different types of cancers. Podosomes are dynamic actin-rich cellular protrusions that facilitate cancer cell invasiveness by degrading extracellular matrix. Whether STIM1-dependent Ca2+ signaling facilitates cancer cell invasion through affecting podosome formation remains unclear. Here we show that the invasive fronts of cancer tissues overexpress STIM1, accompanied by active store-operated Ca2+ entry (SOCE). Interfering SOCE activity by SOCE inhibitors and STIM1 or Orai1 knockdown remarkably affects podosome rosettes formation. Mechanistically, STIM1-silencing significantly alters the podosome rosettes dynamics, shortens the maintenance phase of podosome rosettes and reduces cell invasiveness. The subsequently transient expression of STIM1 cDNA in STIM1-null (STIM1-/-) mouse embryo fibroblasts rescues the suppression of podosome formation, suggesting that STIM1-mediated SOCE activation directly regulates podosome formation. This study uncovers SOCE-mediated Ca2+ microdomain that is the molecular basis for Ca2+ sensitivity controlling podosome formation.

| S-EPMC5599537 | biostudies-literature

Biogenesis of podosome rosettes through fission.

Project description:Podosomes are dynamic actin-based membrane protrusions that are important for extracellular matrix degradation and invasive cell motility. Individual podosomes are often found to organize into large rosette-like structures in some types of cells, such as osteoclasts, endothelial cells, Src-transformed fibroblasts, and certain highly invasive cancer cells. In this study, we show that new podosome rosettes arise through one of two mechanisms; de novo assembly or fission of a pre-existing podosome rosette in Src-transformed fibroblasts. Fission is a more efficient way than de novo assembly to generate new podosome rosettes in these cells. Podosome rosettes undergoing fission possess higher motility and a stronger matrix-degrading capability. Podosome rosette fission may be the result of polarized myosin II-mediated contractility of these structures, which is coordinately regulated by myosin light chain kinase and Rho-associated kinase II. Collectively, this study unveils a previously unknown mechanism-fission for the biogenesis of podosome rosettes.

| S-EPMC5765046 | 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