Phosphatidylinositol 3-Kinase Association with the Osteoclast Cytoskeleton, and Its Involvement in Osteoclast Attachment and Spreading

Lakkakorpi, Päivi T.; Wesolowski, Gregg; Zimolo, Z.; Rodan, Gideon A.; Rodan, Sevgi B.

doi:10.1006/excr.1997.3797

Cited by 72 publications

(52 citation statements)

References 55 publications

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“…Phosphatidylinositol 3-kinase in turn is involved in a reorganization of the cytoskeleton that results in cell spreading and migration of several cell types. In osteoclasts, phosphatidylinositol 3-kinase activity is important for osteoclast activity (25). Our confirmation that Src catalyzes the phosphorylation of CblY 731 and the demonstration that the mutation of that residue to phenylalanine, thereby preventing the Src-catalyzed phosphorylation, inhibits bone resorption further supports our previous suggestion that Cbl is an important substrate of Src in osteoclasts and focuses our attention on phosphatidylinositol 3-kinase as a likely downstream effector of the Pyk2⅐Src⅐Cbl complex.…”

Section: Identification Of Src Kinase-dependent Signaling Events-supporting

confidence: 85%

“…Tyr-731 occurs within the sequence YEAM, which has been shown to provide a docking site for the SH2 domain(s) of the p85 regulatory subunit of phosphatidylinositol 3-kinase (22)(23)(24). Because phosphatidylinositol 3-kinase plays an important role in osteoclast function (25)(26)(27), phosphorylation of Cbl Tyr-731 by Src and the consequent binding of phosphatidylinositol 3-kinase to Cbl could be a critical signaling event. To confirm that Src catalyzes the phosphorylation of Cbl Tyr-731, RAW264.7 cells were treated with PP2, a Src family kinase inhibitor.…”

Section: Identification Of Src Kinase-dependent Signaling Events-mentioning

confidence: 99%

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Src Kinase Activity Is Essential for Osteoclast Function

Miyazaki

Sanjay

Neff

et al. 2004

Journal of Biological Chemistry

260

288

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Section: Identification Of Src Kinase-dependent Signaling Events-supporting

confidence: 85%

Section: Identification Of Src Kinase-dependent Signaling Events-mentioning

confidence: 99%

Src Kinase Activity Is Essential for Osteoclast Function

Miyazaki

Sanjay

Neff

et al. 2004

Journal of Biological Chemistry

260

288

View full text Add to dashboard Cite

“…Inhibition of PI3K activity, ruffled border formation, and bone resorption by wortmannin has been reported in osteoclasts by several studies (85)(86)(87). Involvement of rho p21 protein in osteoclastic bone resorption has also been demonstrated by using the C3 exoenzyme (88).…”

Section: Immunofluorescent Staining Of Various Proteins In Oste-mentioning

confidence: 94%

Phosphatidylinositol 3,4,5-Trisphosphate Directs Association of Src Homology 2-containing Signaling Proteins with Gelsolin

Chellaiah¹,

Biswas²,

Yuen³

et al. 2001

Journal of Biological Chemistry

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Podosomes are adhesion structures in osteoclasts and are structurally related to focal adhesions mediating cell motility during bone resorption. Here we show that gelsolin coprecipitates some of the focal adhesion-associated proteins such as c-Src, phosphoinositide 3-kinase (PI3K), p130Cas , focal adhesion kinase, integrin ␣ v ␤ 3 , vinculin, talin, and paxillin. These proteins were inducibly tyrosine-phosphorylated in response to integrin activation by osteopontin. Previous studies have defined unique biochemical properties of gelsolin related to phosphatidylinositol 3,4,5-trisphosphate in osteoclast podosomes, and here we demonstrate phosphatidylinositol 3,4,5-trisphosphate/gelsolin function in mediating organization of the podosome signaling complex. Overlay and GST pull-down assays demonstrated strong phosphatidylinositol 3,4,5-trisphosphate-PI3K interactions based on the Src homology 2 domains of PI3K. Furthermore, lipid extraction of lysates from activated osteoclasts eliminated interaction between gelsolin, cSrc, PI3K, and focal adhesion kinase despite equal amounts of gelsolin in both the lipid-extracted and unextracted experiment. The cytoplasmic protein tyrosine phosphatase (PTP)-proline-glutamic acid-serine-threonine amino acid sequences (PEST) was also found to be associated with gelsolin in osteoclast podosomes and with stimulation of ␣ v ␤ 3 -regulated phosphorylation of PTP-PEST. We conclude that gelsolin plays a key role in recruitment of signaling proteins to the plasma membrane through phospholipid-protein interactions and by regulation of their phosphorylation status through its association with PTP-PEST. Because both gelsolin deficiency and PI3K inhibition impair bone resorption, we conclude that phosphatidylinositol 3,4,5-trisphosphate-based protein interactions are critical for osteoclast function.Osteoclasts are multinucleated giant cells with bone-resorbing activity. As osteoclasts crawl over bone surfaces, they require rapid attachment and release from the extracellular matrix. Adhesion structures called podosomes present in highly motile cells are also found in osteoclasts. Osteoclasts are unique because they use the speed of podosome assembly and disassembly to generate high rates of motility. Podosome formation stabilizes the bone matrix-cell interface and forms an isolated compartment between the ruffled border and the bone surface (1, 2). Consistent with their function as adhesion sites, podosomes contain many of the same proteins found in focal adhesions, such as F-actin, vinculin, talin, gelsolin, fimbrin, and ␣-actinin (3-7).We have shown previously that osteopontin (OPN) 1 binding to integrin ␣ v ␤ 3 in osteoclasts stimulates gelsolin-associated PI3K. This leads to increased levels of gelsolin-associated polyphosphoinositides, such as phosphatidylinositol 4,5-bisphosphate (PtdIns 4,5-P 2 ), phosphatidylinositol 3,4-bisphosphate, and phosphatidylinositol 3,4,5-trisphosphate, uncapping of actin barbed ends, and actin filament formation (8). Moreover, OPN stimulates gelsolin-associ...

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“…In the culture dish, osteoclastlike cells interact with matrix proteins, which may activate PI 3-K. It has been demonstrated that attachment of osteoclasts to plastic or bone induces a translocation of PI 3-K from the cytosol to the cytoskeleton (25). Furthermore, treatment of chicken osteoclasts with osteopontin activates PI 3-K (42).…”

Section: Discussionmentioning

confidence: 99%

“…The cells polarize and form specialized membrane areas along with the reorganization of cytoskeletal structures (24). During this cellular attachment, PI 3-K translocates from the cytosol to the cytoskeleton (25). Inhibition of PI 3-K inhibits the attachment of osteoclasts, suggesting that the enzyme is required for this process.…”

Section: Introductionmentioning

confidence: 99%

The role of phosphoinositide 3-kinase in spreading osteoclasts induced by colony-stimulating factor-1

Palacio

Félix

2001

European Journal of Endocrinology

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Background: Colony-stimulating factor-1 (CSF-1), a growth and survival factor for osteoclasts, stimulates these cells to spread and migrate towards a gradient of CSF-1. This may support the translocation of osteoclasts to new sites on the bone surface to be resorbed. Phosphoinositide 3-kinase (PI 3-K) is a lipid kinase participating in various signal transduction pathways. Objective: To investigate the role of PI 3-K in the CSF-1-induced spreading of osteoclasts. Methods: In isolated rat osteoclasts treated with or without CSF-1, the distribution of PI 3-K and proteins phosphorylated on tyrosine were investigated using immunofluorescence. In murine osteoclast-like cells grown from bone marrow cells co-cultured with osteoblasts, the activation of the PI 3-K by CSF-1 was determined both in vivo and in vitro. In vivo, the enzyme product in the cell was determined after extraction and separation with thin layer chromatography; in vitro, PI 3-K activity was measured in the pellet immunoprecipitated from the cell lysate. Results: Inhibition of PI 3-K blocked the CSF-1-induced spreading of osteoclasts. In spreading osteoclasts, a portion of PI 3-K was translocated to the periphery where proteins phosphorylated on tyrosine appeared simultaneously. In osteoclast-like cells, CSF-1 stimulated PI 3-K activity. This activity could be immunoprecipitated with antibody against phophotyrosine residues. Conclusion: PI 3-K participates in the CSF-1-induced spreading of osteoclasts. The activated PI 3-K may induce the reorganization of the cytoskeleton resulting in spreading and migration.

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Phosphatidylinositol 3-Kinase Association with the Osteoclast Cytoskeleton, and Its Involvement in Osteoclast Attachment and Spreading

Cited by 72 publications

References 55 publications

Src Kinase Activity Is Essential for Osteoclast Function

Src Kinase Activity Is Essential for Osteoclast Function

Phosphatidylinositol 3,4,5-Trisphosphate Directs Association of Src Homology 2-containing Signaling Proteins with Gelsolin

The role of phosphoinositide 3-kinase in spreading osteoclasts induced by colony-stimulating factor-1

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