Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:2.7.10.2 (
focal adhesion kinase
)
44,029
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Since the effects of progesterone are mediated mainly via estrogen-dependent progesterone receptor (PR), the expression of the effects of progesterone may be masked or overridden by the influence of estrogen under conditions in which priming with estrogens is required. We have established a PR-positive but estrogen receptor-alpha (ER-alpha) negative breast cancer cell model by transfecting PR cDNA into ER-alpha- and PR-negative MDA-MB-231 cells in order that the functions of progesterone can be studied independently of estrogens. We have demonstrated using this model that progesterone markedly inhibited cell growth. We have also discovered that progesterone induced remarkable changes in cell morphology and specific adhesion structures. Progesterone-treated cells became considerably more flattened and well spread than vehicle-treated control cells. This was associated with a striking increase of stress fibers, both in number and diameter, and increased focal contacts as shown by the staining of focal adhesion proteins paxillin and
talin
. There were also distinct increases in tyrosine phosphorylation of focal adhesion protein paxillin and
focal adhesion kinase
in association with increased focal adhesion. The staining of tyrosine-phosphorylated proteins was concentrated at focal adhesions in progesterone-treated cells. More interestingly, monoclonal antibody (Ab) to beta1 integrin was able to inhibit progesterone-induced cell spreading and formation of actin cytoskeleton. To our knowledge, this is the first report describing a direct effect of progesterone in inducing spreading and adhesion of breast cancer cells, and beta1-integrin appeared to play an essential role in the effect. It is known that the initial step of tumor metastasis is the breakaway of tumor cells from primary tumor mass when they lose the ability to attach. Hence, progesterone-induced cell spreading and adhesion may have significant implications in tumor metastasis.
...
PMID:Progesterone induces focal adhesion in breast cancer cells MDA-MB-231 transfected with progesterone receptor complementary DNA. 1070 53
Bone cells transduce mechanical signals into anabolic biochemical responses. However, the mechanisms of mechanotransduction are unknown. To address this issue, we performed studies in primary cells of the human osteoblast lineage grown on collagen/vitronectin-coated supports. We discovered that mechanical strain stimulated a redistribution of the alphavbeta3-integrin to irregular plaque-like areas at the cell-extracellular matrix surface. Proteins involved in integrin-matrix interactions in focal adhesions, vinculin and
talin
, did not localize to the plaque-like areas of alphavbeta3-expression, but signaling molecules such as
focal adhesion kinase
(
FAK
) did. Mechanical strain increased the number and size of the plaques defined by surface expression of alphavbeta3-integrin. Osteopontin was secreted as a cross-linked macromolecular complex, likely through the action of tissue transglutaminase that also was found in the plaques of alphavbeta3-integrin cell-matrix interaction. Mechanical strain increased mineralization of the extracellular matrix that developed in these plaques in alphavbeta3-integrin-dependent manner. Because the plaque-like areas of cell-matrix interaction exhibit macromolecular assembly and mineralization, we conclude that they may represent subcellular domains of bone formation and that alphavbeta3-integrin activation represents one mechanism by which mechanical strain stimulates bone formation.
...
PMID:Mechanically strained cells of the osteoblast lineage organize their extracellular matrix through unique sites of alphavbeta3-integrin expression. 1097 93
Integrins are a large family of cell surface receptors that mediate cell adhesion and influence migration, signal transduction, and gene expression. The cytoplasmic domains of integrins play a pivotal role in these integrin-mediated cellular functions. Through interaction with the cytoskeleton, signaling molecules, and other cellular proteins, integrin cytoplasmic domains transduce signals from both the outside and inside of the cell and regulate integrin-mediated biological functions. Identification and functional analyses of integrin cytoplasmic domain-binding proteins have been pursued intensively. In recent years, more cellular proteins have been reported to directly interact with integrin cytoplasmic domains and some of these interactions may play important roles in integrin-mediated biological responses. Integrin (&bgr;) chains, for example, interact with actin-binding proteins (e.g.
talin
and filamin), which form mechanical links to the cytoskeleton. These and other proteins (e.g.
FAK
, ILK and novel proteins such as TAP20) might also link integrins to signaling mechanisms and, in some cases (e.g. JAB1) mediate integrin-dependent gene regulation.
...
PMID:Integrin cytoplasmic domain-binding proteins. 1101 72
Pyk2 is a member of the
focal adhesion kinase
(
FAK
) family, highly expressed in the central nervous system and haemopoietic cells. Although Pyk2 is homologous to
FAK
, its role in signaling pathways was shown to be distinct from that of
FAK
. We show here that Pyk2 is highly expressed in peritoneal IC-21 macrophage and is tyrosine phosphorylated in response to cell attachment to fibronectin and fibrinogen. Upon IC-21 cell adhesion, Pyk2 tyrosine phosphorylation is inhibited by blocking antibodies to the integrin subunits alpha(M) and beta(2). Furthermore, Pyk2 is rapidly tyrosine phosphorylated in response to ligation of beta(2) integrins by antibodies. In migrating macrophages, Pyk2 localizes to perinuclear regions and to podosomes, where it is clustered with tyrosine phosphorylated proteins. Furthermore, in the podosomal ring structure, which surrounds the central actin core, Pyk2 co-localizes with vinculin,
talin
, and paxillin. In the podosomes, Pyk2 also co-localizes with the integrin alpha(M)beta(2). Lastly, reduction of Pyk2 expression in macrophages leads to inhibition of cell migration. We propose that Pyk2 is functionally linked to the formation of podosomes where it mediates the integrin-cytoskeleton interface and regulates cell spreading and migration.
...
PMID:PYK2 is an adhesion kinase in macrophages, localized in podosomes and activated by beta(2)-integrin ligation. 1105 20
Mutations in the PKD1 gene are responsible for >85% of autosomal dominant polycystic kidney disease (ADPKD). The protein product of PKD1, polycystin-1, is a large, modular membrane protein, with putative ligand-binding motifs in the extracelluar N-terminal portion, 9-11 transmembrane domains and an intracellular C-terminal portion with phosphorylation sites. A role for polycystin-1 as a cell surface receptor involved in cell-matrix and cell-cell interactions has been proposed. In this study, we have analyzed polycystin-1 and associated protein distribution in normal human epithelial cells and examined the role of cell-matrix versus cell-cell interactions in regulation of the assembly of polycystin-1 multiprotein complexes. Immunocytochemistry, sucrose density gradient sedimentation, co-immunoprecipitation analyses and in vitro binding assays have shown that polycystin-1 associates with the focal adhesion proteins
talin
, vinculin, p130Cas,
FAK
, alpha-actinin, paxillin and pp60c-src in subconfluent normal human fetal collecting tubule (HFCT) epithelia when cell-matrix interactions predominate. Polycystin-1 also forms higher S value complexes with the cell-cell adherens junction proteins E-cadherin, beta- and gamma-catenins in confluent cultures when cell-cell interactions are predominant. Polycystin-1 multiprotein complexes can be disrupted by cytochalasin D but not by colchicine, suggesting involvement of the actin cytoskeleton. Although inhibition of tyrosine phosphorylation by tyrphostin inhibits polycystin-1-
FAK
interactions, E-cadherin interactions are enhanced. High calcium treatment also increases polycystin-1-E-cadherin interactions.
...
PMID:Modification of the composition of polycystin-1 multiprotein complexes by calcium and tyrosine phosphorylation. 1111 28
The activated PDGF-receptor has been shown to coimmunoprecipitate together with alpha v beta 3 integrin out of the 15,000g soluble supernatant of non-ionic detergent cell lysates. I have now further characterized this complex by ultracentrifugation analysis. The ultracentrifugation-conditions were chosen so that the phosphorylated form of the PDGF-receptor was pelleted out of the 15,000g soluble supernatant. Together with the tyrosine-phosphorylated PDGF-receptor small amounts of integrins, cytoskeletal- and extracellular matrix proteins were recovered in the pelleted material. The results show that (i) the candidate-fraction of integrins interacting with the activated PDGF-receptor is small compared to the overall integrin population in the cell lysate, (ii) several proteins known to be present in focal adhesions such as
FAK
,
talin
, and vinculin are absent from the integrin-growth factor receptor complexes, while on the other hand (iii) a tyrosine-phosphorylated protein migrating at 120 kDa was highly enriched in the ultracentrifugation-pellet, and finally (iv) non-ionic detergent cell lysates appear to contain quantitatively small fractions of complexed proteins that are qualitatively distinct from their total cellular population. Thus, the separation of protein-complexes from the total cellular proteom may be instrumental for the investigation of cellular protein complexes in general.
...
PMID:Identification of a candidate integrin-fraction associated with the activated form of the PDGF-receptor. 1118 Oct 89
Anchoring filaments are a characteristic feature of initial lymphatic vessels. They connect the abluminal membrane of endothelial cells to the surrounding elastic fibers. The main molecular component of anchoring filaments is fibrillin. Initial lymphatic vessels of human skin were stained with monoclonal antibodies to fibrillin, integrins alpha 2 beta 1, alpha 3 beta 1 and alpha v beta 3, vinculin,
talin
, beta-actin and
focal adhesion kinase
(
FAK
). A double-labeling immunofluorescence method was used to simultaneously stain fibrillin and alpha 3 beta 1 integrin or
FAK
. Close contiguities between integrins and anchoring filaments were observed. These results suggest that the anchoring filaments connect the extracellular matrix and the endothelial cell cytoskeleton through the transmembrane integrin and
FAK
molecule. The results also demonstrate the presence of focal adhesions in the wall of initial lymphatic vessels. These connections possibly enable transmission of chemical and/or mechanical stimuli from the extracellular matrix to the endothelial cells. Here, they are transformed in cytoskeleton rearrangements and intracellular signaling events, some of which may contribute to the initial formation of lymph.
...
PMID:Specific adhesion molecules bind anchoring filaments and endothelial cells in human skin initial lymphatics. 1119 55
Polycystin-1 is a modular membrane protein with a long extracellular N-terminal portion that bears several ligand-binding domains, 11 transmembrane domains, and a > or =200 amino acid intracellular C-terminal portion with several phosphorylation signaling sites. Polycystin-1 is highly expressed in the basal membranes of ureteric bud epithelia during early development of the metanephric kidney, and disruption of the PKD1 gene in mice leads to cystic kidneys and embryonic or perinatal death. It is proposed that polycystin-1 functions as a matrix receptor to link the extracellular matrix to the actin cytoskeleton via focal adhesion proteins. Co-localization, co-sedimentation, and co-immunoprecipitation studies show that polycystin-1 forms multiprotein complexes with alpha2beta1-integrin,
talin
, vinculin, paxillin, p130cas,
focal adhesion kinase
, and c-src in normal human fetal collecting tubules and sub-confluent epithelial cultures. In normal adult kidneys and confluent epithelial cultures, polycystin-1 is downregulated and forms complexes with the cell-cell adherens junction proteins E-cadherin and beta-, gamma-, and alpha-catenin. Polycystin-1 activation at the cell membrane leads to intracellular signaling via phosphorylation through the c-Jun terminal kinase and wnt pathways leading to activation of AP-1 and TCF/LEF-dependent genes, respectively. The C-terminal of polcystin-1 has been shown to be phosphorylated by c-src at Y4237, by protein kinase A at S4252, and by
focal adhesion kinase
and protein kinase X at yet-to-be identified residues. Inhibition of tyrosine phosphorylation or increased cellular calcium increases polycystin-1 focal adhesion complexes versus polycystin-1 adherens junction complexes, whereas disruption of the actin cytoskeleton dissociates all polycystin-1 complexes. Genetic evidence suggests that PKD1, PKD2, NPHP1, and tensin are in the same pathway.
...
PMID:Polycystin: new aspects of structure, function, and regulation. 1127 46
We previously demonstrated that collagen gel overlay induced cell remodeling to form lumen and apoptosis in Madin-Darby canine kidney cells. In the present study, we established that collagen gel overlay-induced apoptosis was initiated at areas exclusive of cell remodeling within 24 h (first phase) and extended into areas of cell remodeling within 48 h (second phase). Collagen gel overlay-induced apoptosis was accompanied by selective proteolysis of
focal adhesion kinase
(
FAK
),
talin
, p130(cas), and c-src. Upon collagen gel overlay,
FAK
was initially degraded into a 90-kDa product during the first phase and subsequently into a 80-kDa product during the second phase. Collagen gel overlay-induced apoptosis of focal adhesion complex proteins and apoptosis of the first phase could be blocked only by a protease inhibitor cocktail. In addition, we found that both DEVD-fmk and ZVAD-fmk inhibited secondary proteolysis of
FAK
, but only ZVAD-fmk blocked collagen gel overlay-induced apoptosis of the second phase. Finally, collagen gel overlay-induced apoptosis and proteolysis of focal adhesion complex proteins were completely inhibited by the combination of protease inhibitor cocktail and ZVAD-fmk. Taken together, collagen gel overlay induces two phases of apoptosis; the first phase is dependent on proteolysis of focal adhesion complex proteins, and the second phase on activation of caspases.
...
PMID:Collagen gel overlay induces two phases of apoptosis in MDCK cells. 1135 Jul 39
This study was directed at the expression of
focal adhesion kinase
(pp125FAK) which is located together with vinculin and
talin
in the spot of cellular adhesion. The authors' intention was to collect reliable data on this important kinase in the signal pathways so as to provide in-depth materials for exploring the mechanism of tumor metastasis to lymphatic vessels. The immunohistochemical method was used to study the expression of
FAK
in lymphatic endothelial cells of metastaltci adenocarcinoma of rectum and its adjacent lymph-nodes. The result demonstrated that lymphatic endothelial cells expressed pp125FAK when lymphatic vessels were invaded by cancer cells. Reaction production was located in the cytoplasm. This study provides that there was a strong correlation between the expression of
FAK
in lymphatic endothelial cells and the metastasis of cancer to lymphatic vessels.
...
PMID:[Expression of focal adhesion kinase in lymphatic endothelial cells of metastasis]. 1138 47
<< Previous
1
2
3
4
5
6
7
8
9
10
Next >>