IndraLab
Statements
EGFR is active.
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"We have shown previously that amino acid residues flanking the phosphotyrosine are important for efficient PTP1 catalysis (Table 1 and Refs. 9, 10, and 17). For example, the kcat/Km value for the undecapeptide, EGFR988-989 (epidermal growth factor autophosphorylation site Tyr992, residues 988-998) (Asp-Ala-Asp-Glu-pTyr-Leu-Ile-Pro-Gln-Gln-Gly) is 3220-fold higher than that of phosphotyrosine (Table 1). We further demonstrated that a minimum of six amino acid residues are required for the most efficient PTP1 binding and catalysis."
"Given that substrate trapping occurred in intact cells and that the interaction was very specific, it is highly likely that egfr and gab1 represent physiological shp2 substrates.To further confirm that phosphotyrosyl proteins trapped by SHP2 are target substrates, we carried out an immunocomplex in vitrophosphatase assay.The WT protein partially dephosphorylated both the EGFR and Gab1, whereas the DM protein did not"
"EGFR possesses three major and two minor tyrosine autophosphorylation sites located at Y1068, Y1148, Y1173, and at Y992 and Y1086 respectively. In addition, EGFR Y1114 is preceded by glutamic acid (Figure 1), which should be preferred by the EGFR kinase as indicated in previous work"
"Inhibition is achieved through the dephosphorylation of RasGAP binding sites at the level of the plasma membrane. We have identified Tyr992 of the epidermal growth factor receptor (EGFR) to be one such site, since its mutation to Phe renders the EGFR refractory to the effect of dominant-negative SHP2. To our knowledge, this is the first report to outline the site and molecular mechanism of action of SHP2 in EGFR signaling,"
"We found that EGF receptor (EGFR) was a direct substrate of VHR and that overexpression of VHR down-regulated EGFR phosphorylation, particularly at Tyr-992 residue. Expression of VHR inhibited the activation of phospholipase Cγ and protein kinase C, both downstream effectors of Tyr-992 phosphorylation of EGFR."
"we show that activated Abl phosphorylates the EGFR primarily on tyrosine 1173Furthermore, we show that activated Abl allows the ligand-activated EGFR to escape Cbl-dependent down-regulation by inhibiting the accumulation of Cbl at the plasma membrane in response to epidermal growth factor stimulation and disrupting the formation of the EGFR.Cbl complex without affecting Cbl protein stability. These findings reveal a novel role for Abl in promoting increased cell-surface expression of the EGFR and suggest that Abl/EGFR signaling may cooperate in human"
"The sh2-domain ptpase shp-1 binds to and dephosphorylates autophosphorylated egfr and may participate in modulation of egfr signaling in epithelial cells. Reduced shp-1 binding to the egfr y1173f mutant resulted in a reduced receptor dephosphorylation by coexpressed shp-1 and less interference with egf-dependent mitogen-activated protein kinase stimulation."
"EGFR possesses three major and two minor tyrosine autophosphorylation sites located at Y1068, Y1148, Y1173, and at Y992 and Y1086 respectively. In addition, EGFR Y1114 is preceded by glutamic acid (Figure 1), which should be preferred by the EGFR kinase as indicated in previous work"
"Revealed that peptides derived from egfr residues y992, y1086, y1101, and y1148 bound directly to the sh2 domain of c-src (figure 8c). These experiments demonstrate that a specific subset of egfr receptor c-src phosphorylation sites are also ligands for the sh2 domain of c-src.Cellular src functions as a co-transducer of transmembrane signals emanating from a variety of growth factor receptors, including egfr"
"EGFR possesses three major and two minor tyrosine autophosphorylation sites located at Y1068, Y1148, Y1173, and at Y992 and Y1086 respectively. In addition, EGFR Y1114 is preceded by glutamic acid (Figure 1), which should be preferred by the EGFR kinase as indicated in previous work"
"Betacellulin is synthesized primarily as a transmembrane precursor, which is then processed to mature molecule by proteolytic events;ten growth factors and their erbb specificities are depicted: egf, amphiregulin((ar), and tgfalfa bind erbb-1, betacellulin, heparin binding egf-like growth factor, and epiregulin bing both erbb-1 and erbb-4."
"Betacellulin is synthesized primarily as a transmembrane precursor, which is then processed to mature molecule by proteolytic events;ten growth factors and their erbb specificities are depicted: egf, amphiregulin((ar), and tgfalfa bind erbb-1, betacellulin, heparin binding egf-like growth factor, and epiregulin bing both erbb-1 and erbb-4."
"Betacellulin is synthesized primarily as a transmembrane precursor, which is then processed to mature molecule by proteolytic events;ten growth factors and their erbb specificities are depicted: egf, amphiregulin((ar), and tgfalfa bind erbb-1, betacellulin, heparin binding egf-like growth factor, and epiregulin bing both erbb-1 and erbb-4."
"Betacellulin is synthesized primarily as a transmembrane precursor, which is then processed to mature molecule by proteolytic events;ten growth factors and their erbb specificities are depicted: egf, amphiregulin((ar), and tgfalfa bind erbb-1, betacellulin, heparin binding egf-like growth factor, and epiregulin bing both erbb-1 and erbb-4."
"EGFR possesses three major and two minor tyrosine autophosphorylation sites located at Y1068, Y1148, Y1173, and at Y992 and Y1086 respectively. In addition, EGFR Y1114 is preceded by glutamic acid (Figure 1), which should be preferred by the EGFR kinase as indicated in previous work"
"EGFR possesses three major and two minor tyrosine autophosphorylation sites located at Y1068, Y1148, Y1173, and at Y992 and Y1086 respectively. In addition, EGFR Y1114 is preceded by glutamic acid (Figure 1), which should be preferred by the EGFR kinase as indicated in previous work"
"Tc45 dephosphorylated delta egfr in u87mg glioblastoma cells and inhibited mitogen-activated protein kinase erk2 and phosphatidylinositol 3-kinase signaling. In contrast, the substrate-trapping tc45-d182a mutant, which is capable of forming stable complexes with tc45 substrates, suppressed the activation of erk2 but not phosphatidylinositol 3-kinase. The activation results in reduced egfr phosphorylation after egf stimulation. Introduction of the alpha(1) cytoplasmic domain peptide into cells induces phosphatase activation and inhibits egf-induced cell proliferation and anchorage-independent growth of malignant cells."
"EGFR possesses three major and two minor tyrosine autophosphorylation sites located at Y1068, Y1148, Y1173, and at Y992 and Y1086 respectively. In addition, EGFR Y1114 is preceded by glutamic acid (Figure 1), which should be preferred by the EGFR kinase as indicated in previous work"
"Tyrosine at residue 1,068 of the EGFR is proposed to be one of the principal phosphorylation sites and Grb2-binding sites stimulated by growth hormone via Jak2. Our results indicate that the role of EGFR in signalling by growth hormone is to be phosphorylated by Jak2, thereby providing docking sites for Grb2 and activating MAP kinases and gene expression, independently of the intrinsic tyrosine kinase activity of EGFR."
"PTPRG activation by the P1-WD peptide affected the tyrosine phosphorylation of several signaling molecules. Data analysis identified 31 molecules whose phosphorylation was modified in a statistically significant manner (Table I). inhibition of ABL1, BMX, BTK, DAB1, ITGB1, JAK2, KDR, KIT, LIMK1, MET, PDGFRB, SHC1, and VCL correlates with tyrosine dephosphorylation. In contrast, SRC inhibition correlates with hyperphosphorylation of the inhibitory Tyr530 residue and with dephosphorylation of the activatory Tyr419. Moreover, CDK2 and CTTN inhibition correlates with a hyperphosphorylation of the inhibitory Tyr15 and Tyr470, respectively. In contrast, a subgroup of 13 proteins, including BLNK, DOK2, ERBB2, GRIN2B, INSR, PDGFRA, PRKCD, PXN, STAT1, STAT2, STAT3, STAT5A, and ZAP70, appears to be activated by PTPRG activity."
"Chemical cross-linking experiments showed that [125i]epiregulin directly bound to each of egfr and erbb-4 but not to erbb-2 and erbb-3. remarkably, three members of the epidermal growth factor (egf) family (ereg, areg, and epgn) showed increased expression that was associated with elevated epidermal activation of the egf receptor (egfr) and stat3, a downstream effector of egfr signaling."
"Biochemical and morphological analyses indicate that threonine-phosphorylated EGFR molecules undergo normal internalization, but instead of sorting to lysosomal degradation, they recycle back to the cell surfaceThe inhibitory effects of pkc are mediated by a single threonine residue (threonine 654) of egfr"
"Oligomerization of receptor protein tyrosine kinases such as the epidermal growth factor receptor (egfr) by their cognate ligands leads to activation of the receptor.We Demonstrate that vav-2 is phosphorylated on tyrosine residues in response to egf and associates with the egfr in vivo."
EGFR is inactive.
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"It is likely that the map2 and ert kinases account for the phosphorylation of the egf receptor at thr669 (egf receptor (krel veplt669psgeapnqallr)) observed in cultured cells.Phosphorylation at ser-695 is partial and occurs only if thr-693 is phosphorylated. Phosphorylation at thr-678 and thr-693 by prkd1 inhibits egf-induced mapk8/jnk1 activation."
"It is likely that the map2 and ert kinases account for the phosphorylation of the egf receptor at thr669 (egf receptor (krel veplt669psgeapnqallr)) observed in cultured cells.Phosphorylation at ser-695 is partial and occurs only if thr-693 is phosphorylated. Phosphorylation at thr-678 and thr-693 by prkd1 inhibits egf-induced mapk8/jnk1 activation."
"A growth factor-stimulated protein kinase activity that phosphorylates the epidermal growth factor (EGF) receptor at Thr669 has been described Anion-exchange chromatography demonstrated that this protein kinase activity was accounted for by two enzymes. The first peak of activity eluted from the column corresponded to the microtubule-associated protein 2 (MAP2) kinase"
"We show that serines 1046/1047 are sites for CaM kinase II phosphorylation, although there is a preference for serine 1047, which resides within the consensus -R-X-X-S-. In addition, we have identified major phosphorylation sites at serine 1142 and serine 1057, which lie within a novel -S-X-D- consensus. Mutation of serines 1046/1047 in full-length EGFR enhanced both fibroblast transformation and tyrosine autokinase activity that was significantly potentiated by additional mutation of serines 1057 and 1142. A single CaM kinase II site was also identified at serine 744 within sub-kinase domain III, and autokinase activity was significantly affected by mutation of this serine to an aspartic acid making this site appear constitutively phosphorylated. We have addressed the mechanism by which CaM kinase II phosphorylation of the EGFR might regulate receptor autokinase activity and show that this modification can hinder association of the cytoplasmic tail with the kinase domain to prevent an enzyme-substrate interaction."
"The mechanism of desensitization of kinase activity can be accounted for, in part, by the EGF-stimulated phosphorylation of the receptor at Ser1046/7, a substrate for the multifunctional calmodulin-dependent protein kinase II in vitro. Mutation of Ser1046/7 by replacement with Ala residues blocks desensitization of the EGF receptor protein-tyrosine kinase activity."
"We report the identification of PTPRK and PTPRJ (density-enhanced phosphatase-1 [DEP-1]) as EGFR-targeting phosphatases. DEP-1 is a tumor suppressor that dephosphorylates and thereby stabilizes EGFR by hampering its ability to associate with the CBL-GRB2 ubiquitin ligase complex|By employing commercially available antibodies, which are supposed to recognize specific tyrosine phosphorylation sites of EGFR, we found that depletion of endogenous DEP-1 nonselectively increased receptor phosphorylation, affecting all three sites we analyzed (tyrosines 1045, 1068, and 1173"
"We show that serines 1046/1047 are sites for CaM kinase II phosphorylation, although there is a preference for serine 1047, which resides within the consensus -R-X-X-S-. In addition, we have identified major phosphorylation sites at serine 1142 and serine 1057, which lie within a novel -S-X-D- consensus. Mutation of serines 1046/1047 in full-length EGFR enhanced both fibroblast transformation and tyrosine autokinase activity that was significantly potentiated by additional mutation of serines 1057 and 1142. A single CaM kinase II site was also identified at serine 744 within sub-kinase domain III, and autokinase activity was significantly affected by mutation of this serine to an aspartic acid making this site appear constitutively phosphorylated. We have addressed the mechanism by which CaM kinase II phosphorylation of the EGFR might regulate receptor autokinase activity and show that this modification can hinder association of the cytoplasmic tail with the kinase domain to prevent an enzyme-substrate interaction."
"The mechanism of desensitization of kinase activity can be accounted for, in part, by the EGF-stimulated phosphorylation of the receptor at Ser1046/7, a substrate for the multifunctional calmodulin-dependent protein kinase II in vitro. Mutation of Ser1046/7 by replacement with Ala residues blocks desensitization of the EGF receptor protein-tyrosine kinase activity."
"Ligand binding to EGFR also leads to rapid internalization and proteosomal/lysosomal degradation of the receptors. This process results in a dramatic downregulation of both total and cell surface receptors. EGF-induced degradation of EGFR is thought to be initiated by phosphorylation of tyrosine 1045 of the receptor followed by binding of Cbl adaptor proteins and ubiquitination of the receptor. Internalized EGFR is transported to early endosomes where receptor-ligand complexes are sorted for either degradation or recycling to the cell surface."
"We show that serines 1046/1047 are sites for CaM kinase II phosphorylation, although there is a preference for serine 1047, which resides within the consensus -R-X-X-S-. In addition, we have identified major phosphorylation sites at serine 1142 and serine 1057, which lie within a novel -S-X-D- consensus. Mutation of serines 1046/1047 in full-length EGFR enhanced both fibroblast transformation and tyrosine autokinase activity that was significantly potentiated by additional mutation of serines 1057 and 1142. A single CaM kinase II site was also identified at serine 744 within sub-kinase domain III, and autokinase activity was significantly affected by mutation of this serine to an aspartic acid making this site appear constitutively phosphorylated. We have addressed the mechanism by which CaM kinase II phosphorylation of the EGFR might regulate receptor autokinase activity and show that this modification can hinder association of the cytoplasmic tail with the kinase domain to prevent an enzyme-substrate interaction."
"We show that serines 1046/1047 are sites for CaM kinase II phosphorylation, although there is a preference for serine 1047, which resides within the consensus -R-X-X-S-. In addition, we have identified major phosphorylation sites at serine 1142 and serine 1057, which lie within a novel -S-X-D- consensus. Mutation of serines 1046/1047 in full-length EGFR enhanced both fibroblast transformation and tyrosine autokinase activity that was significantly potentiated by additional mutation of serines 1057 and 1142. A single CaM kinase II site was also identified at serine 744 within sub-kinase domain III, and autokinase activity was significantly affected by mutation of this serine to an aspartic acid making this site appear constitutively phosphorylated. We have addressed the mechanism by which CaM kinase II phosphorylation of the EGFR might regulate receptor autokinase activity and show that this modification can hinder association of the cytoplasmic tail with the kinase domain to prevent an enzyme-substrate interaction."
"We show that serines 1046/1047 are sites for CaM kinase II phosphorylation, although there is a preference for serine 1047, which resides within the consensus -R-X-X-S-. In addition, we have identified major phosphorylation sites at serine 1142 and serine 1057, which lie within a novel -S-X-D- consensus. Mutation of serines 1046/1047 in full-length EGFR enhanced both fibroblast transformation and tyrosine autokinase activity that was significantly potentiated by additional mutation of serines 1057 and 1142. A single CaM kinase II site was also identified at serine 744 within sub-kinase domain III, and autokinase activity was significantly affected by mutation of this serine to an aspartic acid making this site appear constitutively phosphorylated. We have addressed the mechanism by which CaM kinase II phosphorylation of the EGFR might regulate receptor autokinase activity and show that this modification can hinder association of the cytoplasmic tail with the kinase domain to prevent an enzyme-substrate interaction."
"PTPRG activation by the P1-WD peptide affected the tyrosine phosphorylation of several signaling molecules. Data analysis identified 31 molecules whose phosphorylation was modified in a statistically significant manner (Table I). inhibition of ABL1, BMX, BTK, DAB1, ITGB1, JAK2, KDR, KIT, LIMK1, MET, PDGFRB, SHC1, and VCL correlates with tyrosine dephosphorylation. In contrast, SRC inhibition correlates with hyperphosphorylation of the inhibitory Tyr530 residue and with dephosphorylation of the activatory Tyr419. Moreover, CDK2 and CTTN inhibition correlates with a hyperphosphorylation of the inhibitory Tyr15 and Tyr470, respectively. In contrast, a subgroup of 13 proteins, including BLNK, DOK2, ERBB2, GRIN2B, INSR, PDGFRA, PRKCD, PXN, STAT1, STAT2, STAT3, STAT5A, and ZAP70, appears to be activated by PTPRG activity."
"We report the identification of PTPRK and PTPRJ (density-enhanced phosphatase-1 [DEP-1]) as EGFR-targeting phosphatases. DEP-1 is a tumor suppressor that dephosphorylates and thereby stabilizes EGFR by hampering its ability to associate with the CBL-GRB2 ubiquitin ligase complex|By employing commercially available antibodies, which are supposed to recognize specific tyrosine phosphorylation sites of EGFR, we found that depletion of endogenous DEP-1 nonselectively increased receptor phosphorylation, affecting all three sites we analyzed (tyrosines 1045, 1068, and 1173"
"We report the identification of PTPRK and PTPRJ (density-enhanced phosphatase-1 [DEP-1]) as EGFR-targeting phosphatases. DEP-1 is a tumor suppressor that dephosphorylates and thereby stabilizes EGFR by hampering its ability to associate with the CBL-GRB2 ubiquitin ligase complex|By employing commercially available antibodies, which are supposed to recognize specific tyrosine phosphorylation sites of EGFR, we found that depletion of endogenous DEP-1 nonselectively increased receptor phosphorylation, affecting all three sites we analyzed (tyrosines 1045, 1068, and 1173"
"We show that serines 1046/1047 are sites for CaM kinase II phosphorylation, although there is a preference for serine 1047, which resides within the consensus -R-X-X-S-. In addition, we have identified major phosphorylation sites at serine 1142 and serine 1057, which lie within a novel -S-X-D- consensus. Mutation of serines 1046/1047 in full-length EGFR enhanced both fibroblast transformation and tyrosine autokinase activity that was significantly potentiated by additional mutation of serines 1057 and 1142. A single CaM kinase II site was also identified at serine 744 within sub-kinase domain III, and autokinase activity was significantly affected by mutation of this serine to an aspartic acid making this site appear constitutively phosphorylated. We have addressed the mechanism by which CaM kinase II phosphorylation of the EGFR might regulate receptor autokinase activity and show that this modification can hinder association of the cytoplasmic tail with the kinase domain to prevent an enzyme-substrate interaction."
"We show that serines 1046/1047 are sites for CaM kinase II phosphorylation, although there is a preference for serine 1047, which resides within the consensus -R-X-X-S-. In addition, we have identified major phosphorylation sites at serine 1142 and serine 1057, which lie within a novel -S-X-D- consensus. Mutation of serines 1046/1047 in full-length EGFR enhanced both fibroblast transformation and tyrosine autokinase activity that was significantly potentiated by additional mutation of serines 1057 and 1142. A single CaM kinase II site was also identified at serine 744 within sub-kinase domain III, and autokinase activity was significantly affected by mutation of this serine to an aspartic acid making this site appear constitutively phosphorylated. We have addressed the mechanism by which CaM kinase II phosphorylation of the EGFR might regulate receptor autokinase activity and show that this modification can hinder association of the cytoplasmic tail with the kinase domain to prevent an enzyme-substrate interaction."
EGFR is kinase-active.
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"The first group includes EGF, amphiregulin (AR), and transforming growth factor-alpha (TGF-alpha), which bind specifically to ErbB1; the second group betacellulin (BTC), heparin-binding EGF (HB-EGF), and epiregulin (EPR), which exhibit dual specificity in that they bind ErbB1 and ErbB4. The third group is composed of the neuregulins (NRG) and forms two subgroups based upon their capacity to bind ErbB3 and ErbB4 (NRG-1 and NRG-2) or only ErbB4 (NRG-3 and NRG-4). ErbB2 has no direct ligand and needs a heterodimerization partner to acquire signaling potential ErbB3...has impaired kinase activity."
"The first group includes EGF, amphiregulin (AR), and transforming growth factor-alpha (TGF-alpha), which bind specifically to ErbB1; the second group betacellulin (BTC), heparin-binding EGF (HB-EGF), and epiregulin (EPR), which exhibit dual specificity in that they bind ErbB1 and ErbB4. The third group is composed of the neuregulins (NRG) and forms two subgroups based upon their capacity to bind ErbB3 and ErbB4 (NRG-1 and NRG-2) or only ErbB4 (NRG-3 and NRG-4). ErbB2 has no direct ligand and needs a heterodimerization partner to acquire signaling potential ErbB3...has impaired kinase activity."
"Treatment of the GRP78-underglycosylated EGFR complex with ATP resulted in a release of the underglycosylated EGFR from GRP78, indicating that the complex could be formed through the chaperone function of GRP78. In accordance with the complex formation with endoplasmic reticulum-resident GRP78, the underglycosylated EGFR could not be translocated to the cell surface. As a result, EGF could not induce expression of cyclin D3, a G1 cyclin, in the stressed cells, whereas it did in non-stressed cells."
EGFR is kinase-inactive.
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