Gene/Protein Disease Symptom Drug Enzyme Compound
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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)

Inhibitory immunoreceptors downregulate signaling by recruiting Src homology 2 (SH2) domain-containing tyrosine and/or lipid phosphatases to activating receptor complexes [1]. There are indications that some inhibitory receptors might also perform other functions [2] [3]. In adherent macrophages, two inhibitory receptors, SHPS-1 and PIR-B, are the major proteins binding to the tyrosine phosphatase SHP-1. SHPS-1 also associates with two tyrosine-phosphorylated proteins (pp55 and pp130) and a protein tyrosine kinase [4]. Here, we have identified pp55 and pp130 as the adaptor molecules SKAP55hom/R (Src-kinase-associated protein of 55 kDa homologue) and FYB/SLAP-130 (Fyn-binding protein/SLP-76-associated protein of 130 kDa), respectively, and the tyrosine kinase activity as PYK2. Two distinct SHPS-1 complexes were formed, one containing SKAP55hom/R and FYB/SLAP-130, and the other containing PYK2. Recruitment of FYB/SLAP-130 to SHPS-1 required SKAP55hom/R, whereas PYK2 associated with SHPS-1 independently. Formation of both complexes was independent of SHP-1 and tyrosine phosphorylation of SHPS-1. Finally, tyrosine phosphorylation of members of the SHPS-1 complexes was regulated by integrin-mediated adhesion. Thus, SHPS-1 provides a scaffold for the assembly of multi-protein complexes that might both transmit adhesion-regulated signals and help terminate such signals through SHP-1-directed dephosphorylation. Other inhibitory immunoreceptors might have similar scaffold-like functions.
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PMID:SHPS-1 is a scaffold for assembling distinct adhesion-regulated multi-protein complexes in macrophages. 1046 99

Transcytosis of polymeric immunoglobulin A (pIgA) across epithelial cells is mediated by the polymeric immunoglobulin receptor (pIgR). Binding of pIgA to pIgR stimulates transcytosis of the pIgA-pIgR complex via a signal transduction pathway that is dependent on a protein tyrosine kinase (PTK) of the SRC family. Here we identify the PTK as p62yes. We demonstrate the specific physical and functional association of the pIgR with p62yes in rodent liver. Analysis of p62yes knockout mice revealed a dramatic reduction in the association of tyrosine kinase activity with the pIgR and in transcytosis of pIgA. We conclude that p62yes controls pIgA transcytosis in vivo.
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PMID:The SRC family protein tyrosine kinase p62yes controls polymeric IgA transcytosis in vivo. 1054 94

The focal adhesion kinase (FAK) is a protein tyrosine kinase linked to signaling events between cells and the extracellular matrix. Studies at the Western blot level have demonstrated up-regulation of FAK expression in invasive breast and colon cancers. To assess p125FAK expression at the cellular level, we developed monoclonal antibodies that specifically detected FAK in formalin-fixed, paraffin-embedded tissue sections and analyzed the levels of FAK expression in human breast and colon tissues. Monoclonal antibody 4.47 demonstrated FAK-specific focal adhesion staining by immunofluorescence assays on BT-474 breast cancer cells and detected a Mr 125,000 protein by both Western blotting and immunoprecipitation analyses. Using immunohistochemical techniques, the expression of p125FAK was analyzed in 36 normal and 43 preinvasive or invasive human breast and colon tissues from individual patients. FAK was weakly expressed in most benign breast epithelium but was up-regulated at moderate or strong levels in 14 of 18 invasive breast carcinomas. In seven samples of ductal carcinoma-in situ, FAK was overexpressed. Borderline-to-weak expression of FAK was detected in the normal colonic epithelium. In the invasive colon cancers, FAK was overexpressed at moderate or strong levels in 13 of 15 tumors. Furthermore, FAK expression was up-regulated in areas of dysplastic, premalignant colon epithelium. These results provide the first evidence at the cellular level that FAK expression is variably overexpressed in breast and colon cancer and suggest that up-regulation occurs at an early stage of tumorigenesis.
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PMID:Immunohistochemical analyses of focal adhesion kinase expression in benign and malignant human breast and colon tissues: correlation with preinvasive and invasive phenotypes. 1087 94

Prolactin binds to a member of the cytokine receptor superfamily. The cytoplasmic domain of the prolactin receptor (PrlR) displays no enzymatic activity yet prolactin treatment leads to the induction of protein tyrosine phosphorylation. PrlR is associated with JAK2, a protein tyrosine kinase whose activity is stimulated following receptor dimerization. JAK2 subsequently phosphorylates PrlR and other cellular proteins which are recruited to the activated receptor complex. Among the JAK2 substrates is the transcription factor Stat5 whose phosphorylation mediates the transcriptional activation of beta-casein gene expression. In this review we discuss the prolactin induced signaling pathways which mediate differentiation of the mammary gland.
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PMID:Prolactin mediated intracellular signaling in mammary epithelial cells. 1088 16

Interleukin (IL)-6 decreases cardiac contractility via a nitric oxide (NO)-dependent pathway. However, mechanisms underlying IL-6-induced NO production remain unclear. JAK2/STAT3 and ERK1/2 are two well known signaling pathways activated by IL-6 in non-cardiac cells. However, these IL-6-activated pathways have not been identified in adult cardiac myocytes. In this study, we identified activation of these two pathways during IL-6 stimulation and examined their roles in IL-6-induced NO production and decrease in contractility of adult ventricular myocytes. IL-6 increased phosphorylation of STAT3 (at Tyr(705)) and ERK1/2 (at Tyr(204)) within 5 min that peaked at 15-30 min and returned to basal levels at 2 h. Phosphorylation of STAT3 was blocked by genistein, a protein tyrosine kinase inhibitor, and AG490, a JAK2 inhibitor, but not PD98059, an ERK1/2 kinase inhibitor. The phosphorylation of ERK1/2 was blocked by PD98059 and genistein but not AG490. Furthermore, IL-6 enhanced de novo synthesis of iNOS protein, increased NO production, and decreased cardiac contractility after 2 h of incubation. These effects were blocked by genistein and AG490 but not PD98059. We conclude that IL-6 activated independently the JAK2/STAT3 and ERK1/2 pathways, but only JAK2/STAT3 signaling mediated the NO-associated decrease in contractility.
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PMID:JAK2/STAT3, not ERK1/2, mediates interleukin-6-induced activation of inducible nitric-oxide synthase and decrease in contractility of adult ventricular myocytes. 1259 39

Focal adhesion kinase (FAK) is a protein tyrosine kinase enriched in focal adhesions, which plays a critical role in integrin-dependent cell motility and survival. The crucial step in its activation is autophosphorylation on Tyr-397, which promotes the recruitment of several enzymes including Src family kinases and the activation of multiple signaling pathways. We found in a yeast two-hybrid screen that the N-terminal domain of FAK interacted with protein inhibitor of activated STAT1 (PIAS1). This interaction was confirmed and shown to be direct using in vitro assays. PIAS1 was co-immunoprecipitated with FAK from transfected cells and brain extracts. PIAS1 has recently been recognized as a small ubiquitin-like modifier (SUMO) ligase. In the presence of PIAS1 and SUMO-1, FAK was sumoylated in intact cells, whereas PYK2, a closely related enzyme, was not. Sumoylation occurred on Lys-152, a residue conserved in FAK during evolution. Sumoylated FAK, like PIAS1, was recovered predominantly from the nuclear fraction. Sumoylation did not require the catalytic activity or autophosphorylation of FAK. In contrast, sumoylation increased dramatically the ability of FAK to autophosphorylate in intact cells and in immune precipitate kinase assays. Endogenous FAK was sumoylated in the presence of PIAS1 and SUMO-1 independently of cell adhesion, and autophosphorylation of sumoylated FAK was persistently increased in suspended cells. These observations show that sumoylation controls the activity of a protein kinase and suggest that FAK may play a novel role in signaling between the plasma membrane and the nucleus.
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PMID:PIAS1-mediated sumoylation of focal adhesion kinase activates its autophosphorylation. 1450 Jul 12

Osmotic swelling of cardiac myocytes and other types of cells activates an outwardly rectifying, tamoxifen-sensitive Cl- current, ICl,swell, but it is unclear whether Cl- currents also are activated by direct mechanical stretch. We tested whether specific stretch of beta1-integrin activates a Cl- current in rabbit left ventricular myocytes. Paramagnetic beads (4.5-microm diameter) coated with mAb to beta1-integrin were applied to the surface of myocytes and pulled upward with an electromagnet while recording whole-cell current. In solutions designed to isolate anion currents, beta1-integrin stretch elicited an outwardly rectifying Cl- current with biophysical and pharmacological properties similar to those of ICl,swell. Stretch-activated Cl- current activated slowly (t1/2 = 3.5 +/- 0.1 min), partially inactivated at positive voltages, reversed near ECl, and was blocked by 10 microM tamoxifen. When stretch was terminated, 64 +/- 8% of the stretch-induced current reversed within 10 min. Mechanotransduction involved protein tyrosine kinase. Genistein (100 microM), a protein tyrosine kinase inhibitor previously shown to suppress ICl,swell in myocytes, inhibited stretch-activated Cl- current by 62 +/- 6% during continued stretch. Because focal adhesion kinase and Src are known to be activated by cell swelling, mechanical stretch, and clustering of integrins, we tested whether these tyrosine kinases mediated the response to beta1-integrin stretch. PP2 (10 microM), a selective blocker of focal adhesion kinase and Src, fully inhibited the stretch-activated Cl- current as well as part of the background Cl- current, whereas its inactive analogue PP3 (10 microM) had no significant effect. In addition to activating Cl- current, stretch of beta1-integrin also appeared to activate a nonselective cation current and to suppress IK1. Integrins are the primary mechanical link between the extracellular matrix and cytoskeleton. The present results suggest that integrin stretch may contribute to mechano-electric feedback in heart, modulate electrical activity, and influence the propensity for arrhythmogenesis.
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PMID:Stretch of beta 1 integrin activates an outwardly rectifying chloride current via FAK and Src in rabbit ventricular myocytes. 1461 20

B-lymphocytes are exposed to a reduction/oxidation environment during activation or inflammatory process, and the antioxidant systems are functional to protect themselves against harmful reactive oxygen species (ROS). The crucial roles of thioredoxin-2 (Trx-2) and a DNA repair enzyme APE/Ref-1 in mitochondria are reported in B-lymphocytes. Furthermore, ROS stimulate different signaling pathways in many cellular responses. Their effects often cause some diseases or are utilized for the treatment of other diseases. For example, the cells derived from Fanconi anemia (FA) patients are intolerant of oxidative stress and the therapeutic effect of anti-CD20 monoclonal antibody rituximab on B cell lymphoproliferative disorders is due to the generation of ROS. To clarify the oxidative stress-induced signaling pathways, we stimulated a B cell line with various concentrations of H(2)O(2). As a result, a protein tyrosine kinase, Syk was involved in the induction of G2/M arrest and protection of cells from apoptosis. Syk might inhibit the activation of caspase-9 through Akt thereby protecting cells from oxidative stress-induced apoptosis. On the other hand, Syk-dependent PLC-gamma2 activation was required for acceleration towards apoptosis following oxidative stress. These findings suggest that oxidative stress-induced Syk activation triggers the activation of different pathways, such as pro-apoptotic or survival pathways, and that the balance of these pathways is a key factor in determining the fate of the cells exposed to oxidative stress. In contrast, the stimulation with the millimolar concentrations of H(2)O(2) rapidly led to necrosis in which tyrosine phosphorylation of FAK was involved at the downstream of Lyn and Syk.
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PMID:B cell responses to oxidative stress. 1503 88

Aldosterone is currently recognized as a risk hormone for cardiovascular disease. However, the cellular mechanism by which aldosterone acts on vasculature has not been well understood. In the present study, we investigated whether aldosterone affects angiotensin-converting enzyme (ACE) gene expression in rat endothelial cells. Cultured rat aortic endothelial cells (RAECs) from Sprague-Dawley rats were used in the study. ACE mRNA levels and its enzyme activities in RAECs were examined by real-time RT-PCR and enzyme assay using hippuryl-His-Leu as substrates, respectively. Aldosterone significantly increased steady-state ACE mRNA levels and its enzymatic activities. This effect was dose dependent and time dependent and abolished by mineralocorticoid receptor antagonist spironolactone or transcription inhibitor actinomycin D. Dexamethasone also increased steady-state ACE mRNA levels, whose effect was completely blocked by glucocorticoid receptor antagonist RU486, but not by spironolactone. By contrast, the aldosterone-induced ACE mRNA expression was only partially blocked by RU486. The stimulatory effect of aldosterone on ACE mRNA expression was completely blocked by a protein tyrosine kinase inhibitor (genistein) and JAK2 inhibitor (AG490), partially by Src kinase inhibitor (PP2) and epidermal growth factor receptor kinase inhibitor (AG1478), but not by platelet-derived growth factor receptor kinase inhibitor (AG1296). Transfection of dominant-negative JAK2 construct, but not wild-type construct, significantly blocked the aldosterone-induced ACE mRNA up-regulation. Furthermore, aldosterone induced phosphorylation of JAK2, whose effect was blocked by spironolactone and actinomycin D. In conclusion, the present study demonstrates for the first time that aldosterone induces ACE gene expression and its enzyme activity mainly via a mineralocorticoid receptor-mediated and JAK2-dependent pathway in rat endothelial cells. This may constitute a positive feedback loop for a local renin-angiotensin system, possibly involved in the development of aldosterone-induced endothelial dysfunction and vascular injury.
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PMID:Aldosterone induces angiotensin converting enzyme gene expression via a JAK2-dependent pathway in rat endothelial cells. 1593 31

Microfilaments (actin filaments) regulate various dynamic events during meiotic maturation. Relatively, little is known about the regulation of microfilament organization in mammalian oocytes. Proline-rich tyrosine kinase2 (Pyk2), a protein tyrosine kinase related to focal adhesion kinase (FAK) is essential in actin filaments organization. The present study was to examine the expression and localization of Pyk2, and in particular, its function during rat oocyte maturation. For the first time, by using Western blot and confocal laser scanning microscopy, we detected the expression of Pyk2 in rat oocytes and found that Pyk2 and Try402 phospho-Pyk2 were localized uniformly at the cell cortex and surrounded the germinal vesicle (GV) or the condensed chromosomes at the GV stage or after GV breakdown. At the metaphase and the beginning of anaphase, Pyk2 distributed asymmetrically both in the ooplasm and the cortex with a marked staining associated with the chromosomes and the region overlying the meiotic spindle. At telophase, Pyk2 was observed in the cleavage furrows in addition to its cortex and cytoplasm localization. The dynamics of Pyk2 were similar to that of F-actin, and this kinase was found to co-localize with microfilaments in several developmental stages during rat oocyte maturation. Microinjection of Pyk2 antibody demolished the microfilaments assembly and also inhibited the first polar body (PB1) emission. These findings suggest an important role of Pyk2 for rat oocyte maturation by regulating the organization of actin filaments.
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PMID:Proline-rich tyrosine kinase2 is involved in F-actin organization during in vitro maturation of rat oocyte. 1712 46


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