Gingival epithelial cell signalling and cytoskeletal responses to Porphyromonas gingivalis invasion

Microbiology ◽  
2003 ◽  
Vol 149 (9) ◽  
pp. 2417-2426 ◽  
Author(s):  
Özlem Yilmaz ◽  
Patrick A. Young ◽  
Richard J. Lamont ◽  
George E. Kenny
Keyword(s):  
Porphyromonas Gingivalis ◽  
Focal Adhesion ◽  
Cell Signalling ◽  
Focal Adhesions ◽  
Wild Type ◽  
Cortical Actin ◽  
Membrane Ruffling ◽  
Invasion Mechanism ◽  
Signalling Molecules ◽  
Gingival Epithelial Cell

Porphyromonas gingivalis, an oral pathogen, can internalize within primary gingival epithelial cells (GECs) through an invasion mechanism mediated by interactions between P. gingivalis fimbriae and integrins on the surface of the GECs. Fimbriae–integrin-based signalling events were studied by fluorescence microscopy, and the subcellular localization of integrin-associated signalling molecules paxillin and focal adhesion kinase (FAK), and the architecture of the actin and microtubule cytoskeleton were examined. GECs infected with P. gingivalis for 30 min demonstrated significant redistribution of paxillin and FAK from the cytosol to cell peripheries and assembly into focal adhesion complexes. In contrast, a fimbriae-deficient mutant of P. gingivalis did not contribute substantially to activation of paxillin or FAK. After 24 h, the majority of paxillin and FAK had returned to the cytoplasm with significant co-localization with P. gingivalis in the perinuclear region. Wild-type P. gingivalis induced nucleation of actin filaments forming microspike-like protrusions and long stable microfilaments distributed throughout the cells. Fimbriae mutants promoted a rich cortical actin meshwork accompanied by membrane ruffling dispersed along the cell membrane. Remarkable disassembly and nucleation of the actin and microtubule filamentous network was observed following 24 h infection with either wild-type or fimbriae-deficient mutants of P. gingivalis. The results show that fimbriated P. gingivalis cells induce formation of integrin-associated focal adhesions with subsequent remodelling of the actin and tubulin cytoskeleton.

scholarly journals Integrin alpha 2 cytoplasmic domain deletion effects: loss of adhesive activity parallels ligand-independent recruitment into focal adhesions.

1994 ◽  
Vol 5 (9) ◽  
pp. 977-988 ◽  
Author(s):  
S Kawaguchi ◽  
J M Bergelson ◽  
R W Finberg ◽  
M E Hemler
Keyword(s):  
Amino Acids ◽  
Cell Adhesion ◽  
Focal Adhesion ◽  
Cho Cells ◽  
Chinese Hamster ◽  
Focal Adhesions ◽  
Inverse Correlation ◽  
Cytoplasmic Domain ◽  
Negative Regulator ◽  
Wild Type

Chinese hamster ovary (CHO) cells transfected with the integrin alpha 2 subunit formed a stable VLA-2 heterodimer that mediated cell adhesion to collagen. Within CHO cells spread on collagen, but not fibronectin, wild-type alpha 2 subunit localized into focal adhesion complexes (FACs). In contrast, alpha 2 with a deleted cytoplasmic domain was recruited into FACs whether CHO cells were spread on collagen or fibronectin. Thus, as previously seen for other integrins, the alpha 2 cytoplasmic domain acts as a negative regulator, preventing indiscriminate integrin recruitment into FACs. Notably, ligand-independent localization of the VLA-2 alpha 2 subunit into FACs was partially prevented if only one or two amino acids were present in the alpha 2 cytoplasmic domain (beyond the conserved GFFKR motif) and was completely prevented by four to seven amino acids. The addition of two alanine residues (added to GFFKR) also partially prevented ligand-independent localization. In a striking inverse correlation, the same mutants showing increased ligand-independent recruitment into FACs exhibited diminished alpha 2-dependent adhesion to collagen. Thus, control of VLA-2 localization may be closely related to the suppression of cell adhesion to collagen. In contrast to FAC localization and collagen adhesion results, VLA-2-dependent binding and infection by echovirus were unaffected by either alpha 2 cytoplasmic domain deletion or exchange with other cytoplasmic domains.

scholarly journals Invasion of Epithelial Cells and Proteolysis of Cellular Focal Adhesion Components by Distinct Types of Porphyromonas gingivalis Fimbriae

2006 ◽  
Vol 74 (7) ◽  
pp. 3773-3782 ◽  
Author(s):  
Ichiro Nakagawa ◽  
Hiroaki Inaba ◽  
Taihei Yamamura ◽  
Takahiro Kato ◽  
Shinji Kawai ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Porphyromonas Gingivalis ◽  
Focal Adhesion ◽  
Fluorescent Protein ◽  
Morphological Changes ◽  
Critical Role ◽  
Focal Adhesions ◽  
Cellular Migration ◽  
The Other ◽  
Type Ii

ABSTRACT Porphyromonas gingivalis fimbriae are classified into six types (types I to V and Ib) based on the fimA genes encoding FimA (a subunit of fimbriae), and they play a critical role in bacterial interactions with host tissues. In this study, we compared the efficiencies of P. gingivalis strains with distinct types of fimbriae for invasion of epithelial cells and for degradation of cellular focal adhesion components, paxillin, and focal adhesion kinase (FAK). Six representative strains with the different types of fimbriae were tested, and P. gingivalis with type II fimbriae (type II P. gingivalis) adhered to and invaded epithelial cells at significantly greater levels than the other strains. There were negligible differences in gingipain activities among the six strains; however, type II P. gingivalis apparently degraded intracellular paxillin in association with a loss of phosphorylation 30 min after infection. Degradation was blocked with cytochalasin D or in mutants with fimA disrupted. Paxillin was degraded by the mutant with Lys-gingipain disrupted, and this degradation was prevented by inhibition of Arg-gingipain activity by Nα-p-tosyl-l-lysine chloromethyl ketone. FAK was also degraded by type II P. gingivalis. Cellular focal adhesions with green fluorescent protein-paxillin macroaggregates were clearly destroyed, and this was associated with cellular morphological changes and microtubule disassembly. In an in vitro wound closure assay, type II P. gingivalis significantly inhibited cellular migration and proliferation compared to the cellular migration and proliferation observed with the other types. These results suggest that type II P. gingivalis efficiently invades epithelial cells and degrades focal adhesion components with Arg-gingipain, which results in cellular impairment during wound healing and periodontal tissue regeneration.

scholarly journals Integrin and cytoskeletal regulation of growth factor signaling to the MAP kinase pathway

1999 ◽  
Vol 112 (5) ◽  
pp. 695-706 ◽  
Author(s):  
A.E. Aplin ◽  
R.L. Juliano
Keyword(s):  
Extracellular Matrix ◽  
Growth Factor ◽  
Focal Adhesion ◽  
Adhesion Formation ◽  
Focal Adhesions ◽  
Actin Stress Fiber ◽  
Growth Factor Signaling ◽  
Cortical Actin ◽  
Suspension Cells ◽  
Egf Signaling

Integrin-mediated anchorage of NIH3T3 fibroblasts to the extracellular matrix component fibronectin permits efficient growth factor signaling to the p42 and p44 forms of mitogen-activated protein kinase (MAPK). Since integrins bridge the extracellular matrix to focal adhesion sites and to the actin cytoskeleton, we analyzed the role of these integrin-associated structures in efficient growth factor activation of p42 and p44-MAPKs. Use of specific reagents that disrupt actin stress fiber and focal adhesion formation demonstrated that upon readhesion of NIH3T3 cells to fibronectin, cells that were poorly spread and lacked prominent focal adhesions but that formed cortical actin structures, efficiently signaled to p42 and p44-MAPKs upon EGF stimulation. In contrast, failure to form the cortical actin structures, despite attachment to fibronectin, precluded effective EGF signaling to p42 and p44-MAPKs. Actin cytoskeletal changes induced by expression of dominant-negative and constitutively active forms of Rho GTPases did not alter EGF activation of MAPK in adherent cells. However, active Cdc42, but not active Rac1 or RhoA, partially rescued EGF signaling to p44-MAPK in cells maintained in suspension. These data indicate that a limited degree of adhesion-mediated cytoskeletal organization and focal adhesion complex formation are required for efficient EGF activation of p42 and p44-MAPKs. Our studies exclude a major role for the GTPases RhoA and Rac1 in the formation of cytoskeletal structures relevant for signaling, but indicate that structures regulated by Cdc42 enhance the ability of suspension cells to activate MAPK in response to growth factors.

scholarly journals STIM1 Controls the Focal Adhesion Dynamics and Cell Migration by Regulating SOCE in Osteosarcoma

2021 ◽  
Vol 23 (1) ◽  
pp. 162
Author(s):  
Yu-Shan Lin ◽  
Yi-Hsin Lin ◽  
MyHang Nguyen Thi ◽  
Shih-Chuan Hsiao ◽  
Wen-Tai Chiu
Keyword(s):  
Cell Migration ◽  
Focal Adhesion ◽  
Cancer Metastasis ◽  
Focal Adhesions ◽  
Dominant Negative ◽  
Osteosarcoma Cell ◽  
Wild Type ◽  
Calpain Activity ◽  
The Impact ◽  
Constitutively Active

The dysregulation of store-operated Ca2+ entry (SOCE) promotes cancer progression by changing Ca2+ levels in the cytosol or endoplasmic reticulum. Stromal interaction molecule 1 (STIM1), a component of SOCE, is upregulated in several types of cancer and responsible for cancer cell migration, invasion, and metastasis. To explore the impact of STIM1-mediated SOCE on the turnover of focal adhesion (FA) and cell migration, we overexpressed the wild-type and constitutively active or dominant negative variants of STIM1 in an osteosarcoma cell line. In this study, we hypothesized that STIM1-mediated Ca2+ elevation may increase cell migration. We found that constitutively active STIM1 dramatically increased the Ca2+ influx, calpain activity, and turnover of FA proteins, such as the focal adhesion kinase (FAK), paxillin, and vinculin, which impede the cell migration ability. In contrast, dominant negative STIM1 decreased the turnover of FA proteins as its wild-type variant compared to the cells without STIM1 overexpression while promoting cell migration. These unexpected results suggest that cancer cells need an appropriate amount of Ca2+ to control the assembly and disassembly of focal adhesions by regulating calpain activity. On the other hand, overloaded Ca2+ results in excessive calpain activity, which is not beneficial for cancer metastasis.

scholarly journals RhoB regulates cell migration through altered focal adhesion dynamics

Open Biology ◽  
2012 ◽  
Vol 2 (5) ◽  
pp. 120076 ◽  
Author(s):  
Francisco M. Vega ◽  
Audrey Colomba ◽  
Nicolas Reymond ◽  
Mairian Thomas ◽  
Anne J. Ridley
Keyword(s):  
Cell Migration ◽  
Focal Adhesion ◽  
Rho Gtpase ◽  
Focal Adhesions ◽  
Β1 Integrin ◽  
Membrane Ruffling ◽  
Similar Phenotype ◽  
And Migration ◽  
Directional Cell Migration ◽  
Chemotactic Gradient

The Rho GTPase RhoB has been shown to affect cell migration, but how it does this is not clear. Here we show that cells depleted of RhoB by RNAi are rounded and have defects in Rac-mediated spreading and lamellipodium extension, although they have active membrane ruffling around the periphery. Depletion of the exchange factor GEF-H1 induces a similar phenotype. RhoB-depleted cells migrate faster, but less persistently in a chemotactic gradient, and frequently round up during migration. RhoB-depleted cells have similar numbers of focal adhesions to control cells during spreading and migration, but show more diffuse and patchy contact with the substratum. They have lower levels of surface β1 integrin, and β1 integrin activity is reduced in actin-rich protrusions. We propose that RhoB contributes to directional cell migration by regulating β1 integrin surface levels and activity, thereby stabilizing lamellipodial protrusions.

scholarly journals Arrestins regulate cell spreading and motility via focal adhesion dynamics

2015 ◽  
Vol 26 (4) ◽  
pp. 622-635 ◽  
Author(s):  
Whitney M. Cleghorn ◽  
Kevin M. Branch ◽  
Seunghyi Kook ◽  
Christopher Arnette ◽  
Nada Bulus ◽  
...  
Keyword(s):  
Cell Motility ◽  
Focal Adhesion ◽  
Cell Attachment ◽  
Focal Adhesions ◽  
Cell Spreading ◽  
Wild Type

Focal adhesions (FAs) play a key role in cell attachment, and their timely disassembly is required for cell motility. Both microtubule-dependent targeting and recruitment of clathrin are critical for FA disassembly. Here we identify nonvisual arrestins as molecular links between microtubules and clathrin. Cells lacking both nonvisual arrestins showed excessive spreading on fibronectin and poly-d-lysine, increased adhesion, and reduced motility. The absence of arrestins greatly increases the size and lifespan of FAs, indicating that arrestins are necessary for rapid FA turnover. In nocodazole washout assays, FAs in arrestin-deficient cells were unresponsive to disassociation or regrowth of microtubules, suggesting that arrestins are necessary for microtubule targeting–dependent FA disassembly. Clathrin exhibited decreased dynamics near FA in arrestin-deficient cells. In contrast to wild-type arrestins, mutants deficient in clathrin binding did not rescue the phenotype. Collectively the data indicate that arrestins are key regulators of FA disassembly linking microtubules and clathrin.

scholarly journals Focal Adhesion Targeting: The Critical Determinant of FAK Regulation and Substrate Phosphorylation

1999 ◽  
Vol 10 (8) ◽  
pp. 2507-2518 ◽  
Author(s):  
Yu Shen ◽  
Michael D. Schaller
Keyword(s):  
Cell Adhesion ◽  
Subcellular Localization ◽  
Tyrosine Phosphorylation ◽  
Focal Adhesion ◽  
Focal Adhesions ◽  
Wild Type ◽  
Critical Determinant ◽  
Single Region ◽  
Dependent Cell ◽  
Substrate Phosphorylation

The focal adhesion kinase (FAK) is discretely localized to focal adhesions via its C-terminal focal adhesion–targeting (FAT) sequence. FAK is regulated by integrin-dependent cell adhesion and can regulate tyrosine phosphorylation of downstream substrates, like paxillin. By the use of a mutational strategy, the regions of FAK that are required for cell adhesion–dependent regulation and for inducing tyrosine phosphorylation of paxillin were determined. The results show that the FAT sequence was the single region of FAK that was required for each function. Furthermore, the FAT sequence of FAK was replaced with a focal adhesion–targeting sequence from vinculin, and the resulting chimera exhibited cell adhesion–dependent tyrosine phosphorylation and could induce paxillin phosphorylation like wild-type FAK. These results suggest that subcellular localization is the major determinant of FAK function.

scholarly journals Src SH2 Arginine 175 Is Required for Cell Motility: Specific Focal Adhesion Kinase Targeting and Focal Adhesion Assembly Function

2006 ◽  
Vol 26 (12) ◽  
pp. 4399-4409 ◽  
Author(s):  
Myeong Gu Yeo ◽  
Michael A. Partridge ◽  
Ellen J. Ezratty ◽  
Qiong Shen ◽  
Gregg G. Gundersen ◽  
...  
Keyword(s):  
Cell Motility ◽  
Focal Adhesion Kinase ◽  
Focal Adhesion ◽  
Src Kinase ◽  
Focal Adhesions ◽  
Sh2 Domain ◽  
Wild Type ◽  
Binding Function ◽  
Generation Capacity ◽  
Substrate Phosphorylation

ABSTRACT Src kinase is a crucial mediator of adhesion-related signaling and motility. Src binds to focal adhesion kinase (FAK) through its SH2 domain and subsequently activates it for phosphorylation of downstream substrates. In addition to this binding function, data suggested that the SH2 domain might also perform an important role in targeting Src to focal adhesions (FAs) to enable further substrate phosphorylations. To examine this, we engineered an R175L mutation in cSrc to prevent the interaction with FAK pY397. This constitutively open Src kinase mediated up-regulated substrate phosphorylation in SYF cells but was unable to promote malignant transformation. Significantly, SrcR175L cells also had a profound motility defect and an impaired FA generation capacity. Importantly, we were able to recapitulate wild-type motile behavior and FA formation by directing the kinase to FAs, clearly implicating the SH2 domain in recruitment to FAK and indicating that this targeting capacity, and not simply Src-FAK scaffolding, was critical for normal Src function.

scholarly journals Disruption of the Talin Gene Compromises Focal Adhesion Assembly in Undifferentiated but Not Differentiated Embryonic Stem Cells

1998 ◽  
Vol 142 (4) ◽  
pp. 1121-1133 ◽  
Author(s):  
Helen Priddle ◽  
Lance Hemmings ◽  
Susan Monkley ◽  
Alison Woods ◽  
Bipin Patel ◽  
...  
Keyword(s):  
Focal Adhesion ◽  
Es Cells ◽  
Embryonic Stem ◽  
Focal Adhesions ◽  
Cell Types ◽  
Embryoid Bodies ◽  
Integrin Subunit ◽  
Β1 Integrin ◽  
Es Cell ◽  
Wild Type

We have used gene disruption to isolate two talin (−/−) ES cell mutants that contain no intact talin. The undifferentiated cells (a) were unable to spread on gelatin or laminin and grew as rounded colonies, although they were able to spread on fibronectin (b) showed reduced adhesion to laminin, but not fibronectin (c) expressed much reduced levels of β1 integrin, although levels of α5 and αV were wild-type (d) were less polarized with increased membrane protrusions compared with a vinculin (−/−) ES cell mutant (e) were unable to assemble vinculin or paxillin-containing focal adhesions or actin stress fibers on fibronectin, whereas vinculin (−/−) ES cells were able to assemble talin-containing focal adhesions. Both talin (−/−) ES cell mutants formed embryoid bodies, but differentiation was restricted to two morphologically distinct cell types. Interestingly, these differentiated talin (−/−) ES cells were able to spread and form focal adhesion-like structures containing vinculin and paxillin on fibronectin. Moreover, the levels of the β1 integrin subunit were comparable to those in wild-type ES cells. We conclude that talin is essential for β1 integrin expression and focal adhesion assembly in undifferentiated ES cells, but that a subset of differentiated cells are talin independent for both characteristics.

scholarly journals Regulation of tensin-promoted cell migration by its focal adhesion binding and Src homology domain 2

2003 ◽  
Vol 370 (3) ◽  
pp. 1039-1045 ◽  
Author(s):  
Huaiyang CHEN ◽  
S. Hao LO
Keyword(s):  
Cell Migration ◽  
Focal Adhesion ◽  
Binding Sites ◽  
Focal Adhesions ◽  
Binding Activity ◽  
Wild Type ◽  
New Family ◽  
Promote Cell Migration ◽  
Intracellular Compartments ◽  
Src Homology

Tensin1 is an actin- and phosphotyrosine-binding protein that localizes to focal adhesions. Recently, we have shown that both tensin1 and a new family member, tensin2, promote cell migration [Chen, Duncan, Bozorgchami and Lo (2002) Proc. Natl. Acad. Sci. U.S.A. 99, 733—738]. Since localization of proteins to particular intracellular compartments often regulates their functions, and Src homology domain 2 may mediate signals related to cell migration, we hypothesize that tensin-mediated cell migration is regulated by the focal adhesion localization and the Src homology domain 2 of tensin. To test this hypothesis, we have analysed the effects of a series of tensin1 mutants on cell migration. Our results have shown that (1) tensin1 contains two focal adhesion-binding sites, (2) the wild-type tensin1 significantly promotes cell migration, (3) mutants with one focal adhesion-binding site do not promote cell migration, (4) the non-focal adhesion localized mutant suppresses cell migration and (5) the mutant that is not able to bind to phosphotyrosine-containing proteins has no effect on cell migration. These results have indicated that focal adhesion localization of tensin1 and the phosphotyrosine-binding activity are two critical factors in regulating tensin-mediated cell migration.

Sign in / Sign up

Export Citation Format

Share Document