scholarly journals Phosphorylation of Tyrosine Residues in the Kinase Domain and Juxtamembrane Region Regulates the Biological and Catalytic Activities of Eph Receptors

2000 ◽  
Vol 20 (13) ◽  
pp. 4791-4805 ◽  
Author(s):  
Kathleen L. Binns ◽  
Paul P. Taylor ◽  
Frank Sicheri ◽  
Tony Pawson ◽  
Sacha J. Holland
Keyword(s):  
Tyrosine Kinases ◽  
Biological Activities ◽  
Phosphorylation Site ◽  
Kinase Domain ◽  
Kinase Assay ◽  
Eph Receptors ◽  
Amino Acid Homology ◽  
Tyrosine Residues ◽  
Juxtamembrane Region ◽  
Activation Segment

ABSTRACT Members of the Eph family of receptor tyrosine kinases exhibit a striking degree of amino acid homology, particularly notable in the kinase and membrane-proximal regions. A mutagenesis approach was taken to address the functions of specific conserved tyrosine residues within these catalytic and juxtamembrane domains. Ligand stimulation of wild-type EphB2 in neuronal NG108-15 cells resulted in an upregulation of catalytic activity and an increase in cellular tyrosine phosphorylation, accompanied by a retraction of neuritic processes. Tyrosine-to-phenylalanine substitutions within the conserved juxtamembrane motif abolished these responses. The mechanistic basis for these observations was examined using the highly related EphA4 receptor in a continuous coupled kinase assay. Tandem mass spectrometry experiments confirmed autophosphorylation of the two juxtamembrane tyrosine residues and also identified a tyrosine within the kinase domain activation segment as a phosphorylation site. Kinetic analysis revealed a decreased affinity for peptide substrate upon substitution of activation segment or juxtamembrane tyrosines. Together, our data suggest that the catalytic and therefore biological activities of Eph receptors are controlled by a two-component inhibitory mechanism, which is released by phosphorylation of the juxtamembrane and activation segment tyrosine residues.

Direct binding to and tyrosine phosphorylation of the alpha subunit of the type I interferon receptor by p135tyk2 tyrosine kinase

1994 ◽  
Vol 14 (12) ◽  
pp. 8133-8142 ◽  
Author(s):  
O Colamonici ◽  
H Yan ◽  
P Domanski ◽  
R Handa ◽  
D Smalley ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
Tyrosine Phosphorylation ◽  
Tyrosine Kinases ◽  
Kinase Assay ◽  
Alpha Subunit ◽  
Recombinant Baculoviruses ◽  
Type I ◽  
Receptor Subunit ◽  
Juxtamembrane Region

Binding of type I interferons (IFNs) to their receptors induces rapid tyrosine phosphorylation of multiple proteins, including the alpha and beta subunits of the receptor, the polypeptides that form the transcriptional activator ISGF3 alpha (Stat113, Stat84, and Stat91), and the p135tyk2 and Jak-1 tyrosine kinases. In this report, we demonstrate that the alpha subunit of the type I IFN receptor (IFN-R) corresponds to the product of a previously cloned receptor subunit cDNA and, further, that the p135tyk2 tyrosine kinase directly binds and tyrosine phosphorylates this receptor subunit. Glutathione S-transferase (GST) fusion proteins encoding the different regions of the cytoplasmic domain of the alpha subunit can bind the p135tyk2 contained in human cell lysates. The association between the alpha subunit and Tyk2 was demonstrated by immunoblotting with anti-Tyk2 and antiphosphotyrosine antibodies and by using an in vitro kinase assay. Analogous experiments were then performed with recombinant baculoviruses encoding constitutively active Jak family tyrosine kinases. In this case, p135tyk2, but not Jak-1 or Jak-2 protein, binds to the GST-IFN-R proteins, suggesting that the interaction between these two proteins is both direct and specific. We also demonstrate that Tyk2, from extracts of either IFN alpha-treated human cells or insect cells infected with the recombinant baculoviruses, can catalyze in vitro phosphorylation of GST-IFN-R protein in a specific manner. Deletion mutants of the GST-IFN-R protein were used to localize both the binding and tyrosine phosphorylation site(s) to a 46-amino-acid juxtamembrane region of the alpha subunit, which shows sequence homology to functionally similar regions of other cytokine receptor proteins. These data support the hypothesis that the Tyk2 protein functions as part of a receptor complex to initiate intracellular signaling in response to type I IFNs.

AtCERK1 Phosphorylation Site S493 Contributes to the Transphosphorylation of Downstream Components for Chitin-Induced Immune Signaling

2019 ◽  
Vol 60 (8) ◽  
pp. 1804-1810 ◽  
Author(s):  
Maruya Suzuki ◽  
Issei Yoshida ◽  
Kenkichi Suto ◽  
Yoshitake Desaki ◽  
Naoto Shibuya ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Induced Defense ◽  
Phosphorylation Site ◽  
Defense Responses ◽  
Kinase Domain ◽  
Kinase Assay ◽  
Structural Basis ◽  
Downstream Signaling ◽  
Signaling Components

Abstract While ligand-induced autophosphorylation of receptor-like kinases (RLKs) is known to be critical for triggering the downstream responses, biochemical mechanism by which each phosphorylation site contributes to the initiation of corresponding signaling cascades is only poorly understood, except the involvement of some phosphorylation sites in the regulation of catalytic activity of these RLKs. In this article, we first confirmed that the phosphorylation of S493 of AtCERK1 is involved in the regulation of chitin-induced defense responses by the complementation of an atcerk1 mutant with AtCERK1(S493A) cDNA. In vitro kinase assay with the heterologously expressed kinase domain of AtCERK1, GST-AtCERK1cyt, showed that the S493A mutation did not affect the autophosphorylation of AtCERK1 itself but diminished the transphosphorylation of downstream signaling components, PBL27 and PUB4. On the other hand, a phosphomimetic mutant, GST-AtCERK1(S493D)cyt, transphosphorylated these substrates as similar to the wild type AtCERK1. These results suggested that the phosphorylation of S493 does not contribute to the regulation of catalytic activity but plays an important role for the transphosphorylation of the downstream signaling components, thus contributing to the initiation of chitin signaling. To our knowledge, it is a novel finding that a specific phosphorylation site contributes to the regulation of transphosphorylation activity of RLKs. Further studies on the structural basis by which S493 phosphorylation contributes to the regulation of transphosphorylation would contribute to the understanding how the ligand-induced autophosphorylation of RLKs properly regulates the downstream signaling.

scholarly journals Intramolecular Regulatory Switch in ZAP-70: Analogy with Receptor Tyrosine Kinases

2005 ◽  
Vol 25 (12) ◽  
pp. 4924-4933 ◽  
Author(s):  
Tomas Brdicka ◽  
Theresa A. Kadlecek ◽  
Jeroen P. Roose ◽  
Alexander W. Pastuszak ◽  
Arthur Weiss
Keyword(s):  
Tyrosine Kinases ◽  
Protein Tyrosine Kinase ◽  
Catalytic Domain ◽  
Receptor Tyrosine Kinases ◽  
Kinase Domain ◽  
Sh2 Domains ◽  
Downstream Signaling ◽  
Juxtamembrane Region ◽  
Activated T Cell ◽  
Regulatory Effects

ABSTRACT ZAP-70, a Syk family cytoplasmic protein tyrosine kinase (PTK), is required to couple the activated T-cell antigen receptor (TCR) to downstream signaling pathways. It contains two tandem SH2 domains that bind to phosphorylated TCR subunits and a C-terminal catalytic domain. The region connecting the SH2 domains with the kinase domain, termed interdomain B, has previously been shown to have striking regulatory effects on ZAP-70 function, presumed to be due to the recruitment of key substrates. Paradoxically, deletion of interdomain B preserves ZAP-70 function. Recent structural studies of several receptor tyrosine kinases (RTKs) revealed that their juxtamembrane regions negatively regulate their catalytic activities. In EphB2 and several other RTKs, this autoinhibition depends upon interaction between the kinase domain and tyrosine residues within the juxtamembrane region. Autoinhibition is released when these tyrosines become phosphorylated following receptor stimulation. Sequence homology suggested analogous regulation for ZAP-70. Based on mutagenesis analysis of ZAP-70 interdomain B, we find that this region downregulates ZAP-70 catalytic activity in a similar manner as the juxtamembrane region of EphB2. Similar regulation was also noted for the related Syk kinase. These findings suggest that a general autoinhibitory mechanism employed by RTKs is also used by some cytoplasmic tyrosine kinases.

Stimulation of c-Src by prolactin is independent of Jak2

1999 ◽  
Vol 345 (1) ◽  
pp. 17-24 ◽  
Author(s):  
Juan Ángel FRESNO VARA ◽  
María Victoria CARRETERO ◽  
Haydée GERÓNIMO ◽  
Kurt BALLMER-HOFER ◽  
Jorge MARTÍN-PÉREZ
Keyword(s):  
Tyrosine Kinases ◽  
Kinase Domain ◽  
Receptor Phosphorylation ◽  
Kinase Activation ◽  
Cellular Targets ◽  
Juxtamembrane Region ◽  
Subsequent Activation ◽  
Src Family Tyrosine Kinases ◽  
Chicken Embryo Fibroblasts ◽  
Stimulation Of

Interaction of prolactin (PRL) with its receptor (PRLR) leads to activation of Jak and Src family tyrosine kinases. The PRL/growth hormone/cytokine receptor family conserves a proline-rich sequence in the cytoplasmic juxtamembrane region (Box 1) required for association and subsequent activation of Jaks. In the present work, we studied the mechanisms underlying c-Src kinase activation by PRL and the role that Jak2 plays in this process. PRL addition to chicken embryo fibroblasts (CEF) expressing the rat PRLR long form resulted in activation of c-Src and Jak2 and in tyrosine phosphorylation of the receptor. Receptor phosphorylation was due to associated Jak2, since in cells expressing either a Box 1 mutated PRLR (PRLR4P-A), which is unable to interact with Jak2, or a kinase-domain-deleted Jak2 (Jak2∆k), PRL did not stimulate receptor phosphorylation. Interestingly, addition of PRL to cells expressing PRLR4P-A resulted in an activation of c-Src equivalent to that observed with the wild-type receptor. These findings indicate that PRL-mediated stimulation of c-Src was independent of Jak2 activation and of receptor phosphorylation. Our results suggest that PRL-activated Src could send signals to downstream cellular targets independently of Jak2.

scholarly journals Direct binding to and tyrosine phosphorylation of the alpha subunit of the type I interferon receptor by p135tyk2 tyrosine kinase.

1994 ◽  
Vol 14 (12) ◽  
pp. 8133-8142 ◽  
Author(s):  
O Colamonici ◽  
H Yan ◽  
P Domanski ◽  
R Handa ◽  
D Smalley ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
Tyrosine Phosphorylation ◽  
Tyrosine Kinases ◽  
Kinase Assay ◽  
Alpha Subunit ◽  
Recombinant Baculoviruses ◽  
Type I ◽  
Receptor Subunit ◽  
Juxtamembrane Region

Binding of type I interferons (IFNs) to their receptors induces rapid tyrosine phosphorylation of multiple proteins, including the alpha and beta subunits of the receptor, the polypeptides that form the transcriptional activator ISGF3 alpha (Stat113, Stat84, and Stat91), and the p135tyk2 and Jak-1 tyrosine kinases. In this report, we demonstrate that the alpha subunit of the type I IFN receptor (IFN-R) corresponds to the product of a previously cloned receptor subunit cDNA and, further, that the p135tyk2 tyrosine kinase directly binds and tyrosine phosphorylates this receptor subunit. Glutathione S-transferase (GST) fusion proteins encoding the different regions of the cytoplasmic domain of the alpha subunit can bind the p135tyk2 contained in human cell lysates. The association between the alpha subunit and Tyk2 was demonstrated by immunoblotting with anti-Tyk2 and antiphosphotyrosine antibodies and by using an in vitro kinase assay. Analogous experiments were then performed with recombinant baculoviruses encoding constitutively active Jak family tyrosine kinases. In this case, p135tyk2, but not Jak-1 or Jak-2 protein, binds to the GST-IFN-R proteins, suggesting that the interaction between these two proteins is both direct and specific. We also demonstrate that Tyk2, from extracts of either IFN alpha-treated human cells or insect cells infected with the recombinant baculoviruses, can catalyze in vitro phosphorylation of GST-IFN-R protein in a specific manner. Deletion mutants of the GST-IFN-R protein were used to localize both the binding and tyrosine phosphorylation site(s) to a 46-amino-acid juxtamembrane region of the alpha subunit, which shows sequence homology to functionally similar regions of other cytokine receptor proteins. These data support the hypothesis that the Tyk2 protein functions as part of a receptor complex to initiate intracellular signaling in response to type I IFNs.

scholarly journals Mechanistic Studies of the Mitotic Activation of Mos

2006 ◽  
Vol 26 (14) ◽  
pp. 5300-5309 ◽  
Author(s):  
Jianbo Yue ◽  
James E. Ferrell
Keyword(s):  
Protein Kinase ◽  
Oocyte Maturation ◽  
Tyrosine Kinases ◽  
Spindle Assembly Checkpoint ◽  
Phosphorylation Site ◽  
Kinase Domain ◽  
Mitogen Activated Protein Kinase ◽  
Egg Extracts ◽  
Mitogen Activated Protein

ABSTRACT The protein kinase Mos is responsible for the activation of MEK1 and p42 mitogen-activated protein kinase during Xenopus oocyte maturation and during mitosis in Xenopus egg extracts. Here we show that the activation of Mos depends upon the phosphorylation of Ser 3, a residue previously implicated in the regulation of Mos stability; the dephosphorylation of Ser 105, a previously unidentified phosphorylation site conserved in Mos proteins; and the regulated dissociation of Mos from CK2β. Mutation of Ser 3 to alanine and/or mutation of Ser 105 to glutamate produces a Mos protein that is defective for M-phase activation, as assessed by in vitro kinase assays, and defective for induction of oocyte maturation and maintenance of the spindle assembly checkpoint in extracts. Interestingly, Ser 105 is situated at the beginning of helix αC in the N-terminal lobe of the Mos kinase domain. Changes in the orientation of this helix have been previously implicated in the activation of Cdk2 and Src family tyrosine kinases. Our work suggests that Ser 105 dephosphorylation represents a novel mechanism for reorienting helix αC.

Synthesis and Biological Activity of Quaternary Quinolinium Salts: A Review

2020 ◽  
Vol 23 (21) ◽  
pp. 2271-2294 ◽  
Author(s):  
Divya Utreja ◽  
Shivali Sharma ◽  
Akhil Goyal ◽  
Komalpreet Kaur ◽  
Sonia Kaushal
Keyword(s):  
Tyrosine Kinases ◽  
Biological Activities ◽  
Polymeric Materials ◽  
Tubulin Polymerization ◽  
Quinoline Derivatives ◽  
Heterocyclic Chemistry ◽  
Biological Profile ◽  
Drug Candidates ◽  
Anti Hiv ◽  
Quinolinium Salts

Heterocyclic chemistry is the only branch of chemistry that has applications in varied areas such as dyes, photosensitizers, coordination compounds, polymeric materials, biological, and many other fields. Quinoline and its derivatives have always engrossed both synthetic chemists and biologists because of their diverse chemical and pharmacological properties as these ring systems can be easily found in various natural products, especially in alkaloids. Among alkaloids, quinoline derivatives i.e. quinolinium salts have attracted much attention nowadays owing to their diverse biological profile such as antimicrobial, antitumor, antifungal, hypotensive, anti-HIV, analgesics and anti-inflammatory, etc. Quinoline and its analogs have recently been examined for their modes of function in the inhibition of tyrosine kinases, proteasome, tubulin polymerization, topoisomerase, and DNA repair. These observations have been guiding scientists for the expansion of new quinoline derivatives with improved and varied biological activities. Quinolinium salts have immense possibilities and scope to investigate these compounds as potential drug candidates. Therefore, we shall present a concise compilation of this work to aid in present knowledge and to help researchers explore an interesting quinoline class having medicinal potential.

scholarly journals Dominant Mutations of Drosophila MAP Kinase Kinase and Their Activities in Drosophila and Yeast MAP Kinase Cascades

Genetics ◽  
1997 ◽  
Vol 146 (1) ◽  
pp. 263-273 ◽  
Author(s):  
Young-Mi Lim ◽  
Leo Tsuda ◽  
Yoshihiro H Inoue ◽  
Kenji Irie ◽  
Takashi Adachi-Yamada ◽  
...  
Keyword(s):  
Map Kinase ◽  
Tyrosine Kinases ◽  
Egf Receptor ◽  
Kinase Domain ◽  
Nucleotide Sequencing ◽  
Gain Of Function ◽  
Highly Sensitive ◽  
Mitogen Activated Protein ◽  
Signal Specificity ◽  
Map Kinase Kinase

Eight alleles of Dsor1 encoding a Drosophila homologue of mitogen-activated protein (MAP) kinase kinase were obtained as dominant suppressors of the MAP kinase kinase kinase D-raf. These Dsor1 alleles themselves showed no obvious phenotypic consequences nor any effect on the viability of the flies, although they were highly sensitive to upstream signals and strongly interacted with gain-of-function mutations of upstream factors. They suppressed mutations for receptor tyrosine kinases (RTKs); torso (tor), sevenless (sev) and to a lesser extent Drosophila EGF receptor (DER). Furthermore, the Dsor1 alleles showed no significant interaction with gain-of-function mutations of DER. The observed difference in activity of the Dsor1 alleles among the RTK pathways suggests Dsor1 is one of the components of the pathway that regulates signal specificity. Expression of Dsor1 in budding yeast demonstrated that Dsor1 can activate yeast MAP kinase homologues if a proper activator of Dsor1 is coexpressed. Nucleotide sequencing of the Dsor1 mutant genes revealed that most of the mutations are associated with amino acid changes at highly conserved residues in the kinase domain. The results suggest that they function as suppressors due to increased reactivity to upstream factors.

Protein tyrosine phosphatase-α complexes with the IGF-I receptor and undergoes IGF-I-stimulated tyrosine phosphorylation that mediates cell migration

2009 ◽  
Vol 297 (1) ◽  
pp. C133-C139 ◽  
Author(s):  
Shirley C. Chen ◽  
Ranvikram S. Khanna ◽  
Darrell C. Bessette ◽  
Lionel A. Samayawardhena ◽  
Catherine J. Pallen
Keyword(s):  
Cell Migration ◽  
Tyrosine Phosphorylation ◽  
Protein Tyrosine Phosphatase ◽  
Tyrosine Kinases ◽  
Tyrosine Phosphatase ◽  
Phosphorylation Site ◽  
Protein Tyrosine ◽  
Fibroblast Migration ◽  
Igf I ◽  
In Cells

Protein tyrosine phosphatase-α (PTPα) is a widely expressed receptor-type phosphatase that functions in multiple signaling systems. The actions of PTPα can be regulated by its phosphorylation on serine and tyrosine residues, although little is known about the conditions that promote PTPα phosphorylation. In this study, we tested the ability of several extracellular factors to stimulate PTPα tyrosine phosphorylation. The growth factors IGF-I and acidic FGF induced the highest increase in PTPα phosphorylation at tyrosine 789, followed by PMA and lysophosphatidic acid, while EGF had little effect. Further investigation of IGF-I-induced PTPα tyrosine phosphorylation demonstrated that this occurs through a novel Src family kinase-independent mechanism that does not require focal adhesion kinase, phosphatidylinositol 3-kinase, or MEK. We also show that PTPα physically interacts with the IGF-I receptor. In contrast to IGF-I-induced PTPα phosphorylation, this association does not require IGF-I. The interaction of PTPα and the IGF-I receptor is independent of PTPα catalytic activity, and expression of exogenous PTPα does not promote IGF-I receptor tyrosine dephosphorylation, indicating that PTPα does not act as an IGF-I receptor phosphatase. However, PTPα mediates IGF-I signaling, because IGF-I-stimulated fibroblast migration was reduced by ∼50% in cells lacking PTPα or in cells with mutant PTPα lacking the tyrosine 789 phosphorylation site. Our results suggest that PTPα tyrosine phosphorylation can occur in response to diverse stimuli and can be mediated by various tyrosine kinases. In the case of IGF-I, we propose that IGF-I-induced tyrosine 789 phosphorylation of PTPα, possibly catalyzed by the PTPα-associated IGF-I receptor tyrosine kinase, is required for efficient cell migration in response to this growth factor.

After chronic myelogenous leukemia: tyrosine kinase inhibitors in other hematologic malignancies

Blood ◽  
2005 ◽  
Vol 105 (1) ◽  
pp. 22-30 ◽  
Author(s):  
Martha Wadleigh ◽  
Daniel J. DeAngelo ◽  
James D. Griffin ◽  
Richard M. Stone
Keyword(s):  
Cell Growth ◽  
Small Molecules ◽  
Chronic Myelogenous Leukemia ◽  
Tyrosine Kinases ◽  
Kinase Inhibitors ◽  
Hematologic Malignancies ◽  
Myelogenous Leukemia ◽  
Pathologic Feature ◽  
Growth And Survival ◽  
Tyrosine Residues

AbstractTyrosine kinases phosphorylate proteins on tyrosine residues, producing a biologic signal that influences many aspects of cellular function including cell growth, proliferation, differentiation, and death. Constitutive or unregulated activity through mutation or overexpression of these enzymes is a common pathologic feature in many acute and chronic leukemias. Inhibition of tyrosine kinases represents a strategy to disrupt signaling pathways that promote neoplastic growth and survival in hematologic malignancies and likely in other neoplasias as well. This review focuses on tyrosine kinases that have been implicated in the pathogenesis of hematologic diseases other than chronic myelogenous leukemia and discusses the evidence for the use of small molecules to target these kinases.

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