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Query: EC:2.7.10.2 (
focal adhesion kinase
)
44,029
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Regulatory interactions among individual receptor-coupled signal transduction systems are critically important for establishing cellular responses in the face of multiple stimuli. In this study, potential regulatory interactions between signal transduction systems activated by growth factor receptors and by G-protein-coupled receptors were examined using human neuroblastoma SH-SY5Y cells which express endogenous epidermal growth factor (EGF) and muscarinic M3 receptors. Activation of muscarinic receptors with carbachol was found to inhibit EGF-induced signaling, including tyrosine phosphorylation of the
adaptor protein
Cbl and of the EGF receptor, and complex formation between Shc proteins and the EGF receptor and Grb2. Protein kinase C, which is activated by muscarinic M3 receptors, mediated this inhibitory cross-talk. Activation of EGF receptors was found to inhibit muscarinic receptor-induced tyrosine phosphorylation of
focal adhesion kinase
and paxillin. Reactive oxygen species, which are formed as components of the EGF signaling cascade, mediated this inhibitory cross-talk. These mutual inhibitory interactions demonstrate novel mechanisms for neuronal integration of multiple signals generated by activation of receptors by neurotransmitters and growth factors.
...
PMID:Muscarinic M3 and epidermal growth factor receptors activate mutually inhibitory signaling cascades in human neuroblastoma SH-SY5Y cells. 1004 86
Dystroglycan is a transmembrane heterodimeric complex of alpha and beta subunits that links the extracellular matrix to the cell cytoskeleton. It was originally identified in skeletal muscle, where it anchors dystrophin to the sarcolemma. Dystroglycan is also highly expressed in nonmuscle tissues, including brain. To investigate the molecular interactions of dystroglycan in the CNS, we fractionated a digitonin-soluble extract from bovine brain synaptosomes by laminin-affinity chromatography and characterized the protein components. The 120-kDa alpha-dystroglycan was the major 125I-laminin-labeled protein detected by overlay assay. This complex, in addition to beta-dystroglycan, was also found to contain Grb2 and
focal adhesion kinase
p125FAK (FAK). Anti-FAK antibodies co-immunoprecipitated Grb2 with FAK. However, no direct interaction between beta-dystroglycan and FAK was detected by co-precipitation assay. Grb2, an
adaptor protein
involved in signal transduction and cytoskeleton organization, has been shown to bind beta-dystroglycan. We isolated both FAK and Grb2 from synaptosomal extracts by chromatography on immobilized recombinant beta-dystroglycan. In the CNS, FAK phosphorylation has been linked to membrane depolarization and neurotransmitter receptor activation. At the synapses, the
adaptor protein
Grb2 may mediate FAK-beta-dystroglycan interaction, and it may play a role in transferring information between the dystroglycan complex and other signaling pathways.
...
PMID:Association of the dystroglycan complex isolated from bovine brain synaptosomes with proteins involved in signal transduction. 1009 73
The SH2-SH3 domain-containing
adaptor protein
CRKL is the predominant tyrosine phosphorylated protein in chronic myelogenous leukemia (CML) neutrophils and BCR-
ABL
-expressing cell lines. The amino terminal CRKL SH3 domain binds directly to a proline-rich region in the C-terminus of BCR-
ABL
. BCR-
ABL
mutants with deletions of this region were constructed to assess biologic effects of eliminating the CRKL binding site. Yeast two-hybrid analysis and gel overlay assays show eradication of the direct interaction of CRKL with BCR-
ABL
in the proline deletion mutants. However, these BCR-
ABL
mutants transform myeloid cells to growth factor independence, and in these cells CRKL is tyrosine phosphorylated and associates with BCR-
ABL
. These findings suggest both direct and indirect interactions of CRKL with BCR-
ABL
. Thus, disruption of the direct interaction with BCR-
ABL
has not excluded a role for CRKL in BCR-
ABL
-mediated transformation.
...
PMID:CRKL binding to BCR-ABL and BCR-ABL transformation. 1019 28
Paxillin is a focal adhesion
adaptor protein
involved in the integration of growth factor- and adhesion-mediated signal transduction pathways. Repeats of a leucine-rich sequence named paxillin LD motifs (Brown M.C., M.S. Curtis, and C.E. Turner. 1998. Nature Struct. Biol. 5:677-678) have been implicated in paxillin binding to
focal adhesion kinase
(
FAK
) and vinculin. Here we demonstrate that the individual paxillin LD motifs function as discrete and selective protein binding interfaces. A novel scaffolding function is described for paxillin LD4 in the binding of a complex of proteins containing active p21 GTPase-activated kinase (PAK), Nck, and the guanine nucleotide exchange factor, PIX. The association of this complex with paxillin is mediated by a new 95-kD protein, p95PKL (paxillin-kinase linker), which binds directly to paxillin LD4 and PIX. This protein complex also binds to Hic-5, suggesting a conservation of LD function across the paxillin superfamily. Cloning of p95PKL revealed a multidomain protein containing an NH2-terminal ARF-GAP domain, three ankyrin-like repeats, a potential calcium-binding EF hand, calmodulin-binding IQ motifs, a myosin homology domain, and two paxillin-binding subdomains (PBS). Green fluorescent protein- (GFP-) tagged p95PKL localized to focal adhesions/complexes in CHO.K1 cells. Overexpression in neuroblastoma cells of a paxillin LD4 deletion mutant inhibited lamellipodia formation in response to insulin-like growth fac- tor-1. Microinjection of GST-LD4 into NIH3T3 cells significantly decreased cell migration into a wound. These data implicate paxillin as a mediator of p21 GTPase-regulated actin cytoskeletal reorganization through the recruitment to nascent focal adhesion structures of an active PAK/PIX complex potentially via interactions with p95PKL.
...
PMID:Paxillin LD4 motif binds PAK and PIX through a novel 95-kD ankyrin repeat, ARF-GAP protein: A role in cytoskeletal remodeling. 1033 Apr 11
We compared the intracellular signalling pathways through Ret tyrosine kinase activated by glial cell line-derived neurotrophic factor (GDNF), multiple endocrine neoplasia (MEN) 2A, or MEN 2B mutation. Tyrosine phosphorylation of Grb2-associated binder-1 (Gab1) and activation of phosphatidylinositol 3-kinase (PI 3-kinase) were induced at higher levels by GDNF stimulation or the MEN 2B mutation than by the MEN 2A mutation. Tyrosine-phosphorylated Gab1 was a major component that interacted with the active PI 3-kinase in vivo. In addition, we found that p62Dok and
PKB
/Akt were phosphorylated in a PI 3-kinase-dependent manner and the levels of their phosphorylation were significantly higher in the MEN 2B transfectant than in the MEN 2A transfectant. Tyrosine phosphorylation of p62Dok resulted in its complex formation with the Ras GTPase-activating protein (RasGAP) and the Nck
adaptor protein
. These findings thus suggested that high levels of activation of PI 3-kinase and of phosphorylation of its downstream signalling molecules may be associated with the clinical phenotype of MEN 2B.
...
PMID:Enhanced phosphatidylinositol 3-kinase activity and high phosphorylation state of its downstream signalling molecules mediated by ret with the MEN 2B mutation. 1044 70
The level of phosphorylation within cells is tightly regulated by the concerted action of protein kinases and protein phosphatases [Hunter, T. (1995) Cell 80, 225-236]. Disregulation in the activity of either of these players can lead to cellular transformation. Many protein tyrosine kinases are proto-oncogenes and it has been postulated that some protein phosphatases may act as tumor suppressors. Herein we will review the recent findings addressing the roles the candidate tumor suppressor PTEN/MMAC1/TEP1 (PTEN, phosphatase and tensin homologue deleted from chromosome 10; MMAC 1, mutated in multiple advanced cancers 1; TEP1, TGF beta regulated and epithelial cell enriched phosphatase 1) plays in signal transduction and tumorigenesis. PTEN is a dual specificity protein phosphatase (towards phospho-Ser/Thr and phospho-Tyr) and, unexpectedly, also has a phosphoinositide 3-phosphatase activity. PTEN plays an important role in the modulation of the 1-phosphatidylinositol 3-kinase (PtdIns 3-kinase) pathway, by catalyzing the degradation of the PtdIns(3,4,5)P3 generated by PtdIns 3-kinase; this inhibits the downstream functions mediated by the PtdIns 3-kinase pathway, such as activation of protein kinase B (
PKB
, also known as Akt), cell survival and cell proliferation. Furthermore, PTEN modulates cell migration and invasion by negatively regulating the signals generated at the focal adhesions, through the direct dephosphorylation and inhibition of
focal adhesion kinase
(
FAK
). Growth factor receptor signaling is also negatively regulated by PTEN, through the inhibition of the
adaptor protein
Shc. While some of the functions of PTEN have been elucidated, it is clear that there is much more to discover about the roles of this unique protein.
...
PMID:PTEN/MMAC1/TEP1 in signal transduction and tumorigenesis. 1046 23
We have examined the mechanism by which collagen-binding integrins co-operate with insulin-like growth factor-I (IGF-I) receptors (IGF-IR) to regulate chondrocyte phenotype and differentiation. Adhesion of chondrocytes to anti-beta1 integrin antibodies or collagen type II leads to phosphorylation of cytoskeletal and signalling proteins localized at focal adhesions, including alpha-actinin, vinculin, paxillin and
focal adhesion kinase
(
FAK
). These stimulate docking proteins such as Shc (Src-homology collagen). Moreover, exposure of collagen type II-cultured chondrocytes to IGF-I leads to co-immunoprecipitation of Shc protein with the IGF-IR and with beta1, alpha1 and alpha5 integrins, but not with alpha3 integrin. Shc then associates with growth factor receptor-bound protein 2 (Grb2), an
adaptor protein
and extracellular signal-regulated kinase. The expression of the docking protein Shc occurs only when chondrocytes are bound to collagen type II or integrin antibodies and increases when IGF-I is added, suggesting a collaboration between integrins and growth factors in a common/shared biochemical signalling pathway. Furthermore, these results indicate that focal adhesion assembly may facilitate signalling via Shc, a potential common target for signal integration between integrin and growth-factor signalling regulatory pathways. Thus, the collagen-binding integrins and IGF-IR co-operate to regulate focal adhesion components and these signalling pathways have common targets (Shc-Grb2 complex) in subcellular compartments, thereby linking to the Ras-mitogen-activated protein kinase signalling pathway. These events may play a role during chondrocyte differentiation.
...
PMID:Signal transduction by beta1 integrin receptors in human chondrocytes in vitro: collaboration with the insulin-like growth factor-I receptor. 1047 72
T-cell activation involves the participation of protein-tyrosine kinases p56(lck) and ZAP-70/
SYK
as well as lymphoid proteins such as SLP-76 and FYB/SLAP. FYB/SLAP has the hallmarks of an
adaptor protein
that binds to the SH2 domains of the Src kinase
FYN
-T and SLP-76. Whereas two forms of FYB at 120 and 130 kDa have been identified biochemically, a cDNA encoding only the lower molecular weight isoform has been cloned (termed FYB-120 or SLAP-130). In this study, we report the isolation of an alternative isoform of FYB with a molecular mass of 130 kDa (FYB-130) that has the same structure as FYB-120 except for an insertion of 46 amino acids toward the carboxyl-terminal region of the protein. FYB-120 and FYB-130 share an ability to bind to the SH2 domains of
FYN
-T and SLP-76, to act as substrates for p59(FYN-T), and to be expressed in the cytoplasm and nucleus of T-cells. Differences were noted between the isoforms in the efficiency of binding to SLP-76 and in the preferential expression of FYB-130 in mature T-cells. When co-expressed together with
FYN
-T and SLP-76, FYB-130 caused a significant increase in anti-CD3-driven NF-AT transcription. Finally, fluorescence in situ hybridization analysis localized the FYB gene to human chromosome 5 at position p13.1. FYB-130 therefore represents a novel variant of FYB protein that can up-regulate T-cell receptor-driven interleukin 2 production in mature T-cells.
...
PMID:Novel isoform of lymphoid adaptor FYN-T-binding protein (FYB-130) interacts with SLP-76 and up-regulates interleukin 2 production. 1049 4
Integrin-linked kinase (ILK) is a focal adhesion serine/threonine protein kinase that is emerging as a key signaling protein functioning at one of the early convergence points of integrin- and growth factor-signaling pathways. ILK binds to PINCH through the N-terminal ankyrin (ANK) repeat domain and the PINCH binding is crucial for focal adhesion localization of ILK. The ILK-PINCH interaction also connects ILK to Nck-2, an SH2-SH3-containing
adaptor protein
that interacts with components of growth factor and small GTPase signaling pathways. The kinase activity of ILK is regulated by both cell adhesion and growth factors in a phosphoinositide 3-kinase (PI3K)-dependent manner. ILK phosphorylates downstream targets such as protein kinase B (
PKB
, also known as Akt) and glycogen synthase kinase 3 (GSK-3) and regulates their activities. Overexpression of ILK in epithelial cells leads to striking morphological changes mimicking epithelial-mesenchymal transition, including upregulation of integrin-mediated fibronectin matrix assembly and downregulation of cell-cell adhesions. Furthermore, ILK regulates nuclear translocation of (beta)-catenin and gene expression, and promotes cell cycle progression and tumor formation. Recent genetic studies in Drosophila melanogaster and Caenorhabditis elegans have shown that lack of expression of ILK or PINCH results in phenotypes resembling those of integrin-null mutants, which demonstrates that ILK and PINCH are indispensable for integrin function during embryonic development.
...
PMID:Integrin-linked kinase and PINCH: partners in regulation of cell-extracellular matrix interaction and signal transduction. 1057 98
A novel T cell-specific
adaptor protein
, RIBP, was identified based on its ability to bind
Rlk
/Txk in a yeast two-hybrid screen of a mouse T cell lymphoma library. RIBP was also found to interact with a related member of the Tec family of tyrosine kinases, Itk. Expression of RIBP is restricted to T and natural killer cells and is upregulated substantially after T cell activation. RIBP-disrupted knockout mice displayed apparently normal T cell development. However, proliferation of RIBP-deficient T cells in response to T cell receptor (TCR)-mediated activation was significantly impaired. Furthermore, these activated T cells were defective in the production of interleukin (IL)-2 and interferon gamma, but not IL-4. These data suggest that RIBP plays an important role in TCR-mediated signal transduction pathways and that its binding to Itk and
Rlk
/Txk may regulate T cell differentiation.
...
PMID:RIBP, a novel Rlk/Txk- and itk-binding adaptor protein that regulates T cell activation. 1058 56
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