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[[ | ==Structural and Biophysical Characterization of the Syk Activation Switch== | ||
<StructureSection load='4fl2' size='340' side='right' caption='[[4fl2]], [[Resolution|resolution]] 2.19Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[4fl2]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4FL2 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4FL2 FirstGlance]. <br> | |||
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=ANP:PHOSPHOAMINOPHOSPHONIC+ACID-ADENYLATE+ESTER'>ANP</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene></td></tr> | |||
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[4fl1|4fl1]], [[4fl3|4fl3]]</td></tr> | |||
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">SYK ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 Homo sapiens])</td></tr> | |||
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Non-specific_protein-tyrosine_kinase Non-specific protein-tyrosine kinase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.10.2 2.7.10.2] </span></td></tr> | |||
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4fl2 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4fl2 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4fl2 RCSB], [http://www.ebi.ac.uk/pdbsum/4fl2 PDBsum]</span></td></tr> | |||
</table> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Syk is an essential non-receptor tyrosine kinase in intracellular immunological signaling, and the control of Syk kinase function is considered as a valuable target for pharmacological intervention in autoimmune or inflammation diseases. Upon immune receptor stimulation, the kinase activity of Syk is regulated by binding of phosphorylated immune receptor tyrosine-based activating motifs (pITAMs) to the N-terminal tandem Src homology 2 (tSH2) domain and by autophosphorylation with consequences for the molecular structure of the Syk protein. Here, we present the first crystal structures of full-length Syk (fl-Syk) as wild type and as Y348F/Y352F mutant forms in complex with AMP-PNP revealing an autoinhibited conformation. The comparison with the crystal structure of the truncated Syk kinase domain in complex with AMP-PNP taken together with ligand binding studies by surface plasmon resonance (SPR) suggests conformational differences in the ATP sites of autoinhibited and activated Syk forms. This hypothesis was corroborated by studying the thermodynamic and kinetic interaction of three published Syk inhibitors with isothermal titration calorimetry and SPR, respectively. We further demonstrate the modulation of inhibitor binding affinities in the presence of pITAM and discuss the observed differences of thermodynamic and kinetic signatures. The functional relevance of pITAM binding to fl-Syk was confirmed by a strong stimulation of in vitro autophosphorylation. A structural feedback mechanism on the kinase domain upon pITAM binding to the tSH2 domain is discussed in analogy of the related family kinase ZAP-70 (Zeta-chain-associated protein kinase 70). Surprisingly, we observed distinct conformations of the tSH2 domain and the activation switch including Tyr348 and Tyr352 in the interdomain linker of Syk in comparison to ZAP-70. | |||
Structural and Biophysical Characterization of the Syk Activation Switch.,Gradler U, Schwarz D, Dresing V, Musil D, Bomke J, Frech M, Greiner H, Jakel S, Rysiok T, Muller-Pompalla D, Wegener A J Mol Biol. 2012 Nov 12. pii: S0022-2836(12)00879-0. doi:, 10.1016/j.jmb.2012.11.007. PMID:23154170<ref>PMID:23154170</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
==See Also== | |||
*[[Tyrosine kinase|Tyrosine kinase]] | |||
== | == References == | ||
[[ | <references/> | ||
__TOC__ | |||
</StructureSection> | |||
[[Category: Homo sapiens]] | [[Category: Homo sapiens]] | ||
[[Category: Non-specific protein-tyrosine kinase]] | [[Category: Non-specific protein-tyrosine kinase]] | ||
[[Category: Bomke, J | [[Category: Bomke, J]] | ||
[[Category: Dresing, V | [[Category: Dresing, V]] | ||
[[Category: Frech, M | [[Category: Frech, M]] | ||
[[Category: Graedler, U | [[Category: Graedler, U]] | ||
[[Category: Jaekel, S | [[Category: Jaekel, S]] | ||
[[Category: Mueller-Pompalla, D | [[Category: Mueller-Pompalla, D]] | ||
[[Category: Musil, M | [[Category: Musil, M]] | ||
[[Category: Rysiok, T | [[Category: Rysiok, T]] | ||
[[Category: Schwarz, D | [[Category: Schwarz, D]] | ||
[[Category: Wegener, A | [[Category: Wegener, A]] | ||
[[Category: Protein kinase]] | [[Category: Protein kinase]] | ||
[[Category: Transferase]] | [[Category: Transferase]] | ||
Revision as of 17:29, 9 December 2014
Structural and Biophysical Characterization of the Syk Activation SwitchStructural and Biophysical Characterization of the Syk Activation Switch
Structural highlights
Publication Abstract from PubMedSyk is an essential non-receptor tyrosine kinase in intracellular immunological signaling, and the control of Syk kinase function is considered as a valuable target for pharmacological intervention in autoimmune or inflammation diseases. Upon immune receptor stimulation, the kinase activity of Syk is regulated by binding of phosphorylated immune receptor tyrosine-based activating motifs (pITAMs) to the N-terminal tandem Src homology 2 (tSH2) domain and by autophosphorylation with consequences for the molecular structure of the Syk protein. Here, we present the first crystal structures of full-length Syk (fl-Syk) as wild type and as Y348F/Y352F mutant forms in complex with AMP-PNP revealing an autoinhibited conformation. The comparison with the crystal structure of the truncated Syk kinase domain in complex with AMP-PNP taken together with ligand binding studies by surface plasmon resonance (SPR) suggests conformational differences in the ATP sites of autoinhibited and activated Syk forms. This hypothesis was corroborated by studying the thermodynamic and kinetic interaction of three published Syk inhibitors with isothermal titration calorimetry and SPR, respectively. We further demonstrate the modulation of inhibitor binding affinities in the presence of pITAM and discuss the observed differences of thermodynamic and kinetic signatures. The functional relevance of pITAM binding to fl-Syk was confirmed by a strong stimulation of in vitro autophosphorylation. A structural feedback mechanism on the kinase domain upon pITAM binding to the tSH2 domain is discussed in analogy of the related family kinase ZAP-70 (Zeta-chain-associated protein kinase 70). Surprisingly, we observed distinct conformations of the tSH2 domain and the activation switch including Tyr348 and Tyr352 in the interdomain linker of Syk in comparison to ZAP-70. Structural and Biophysical Characterization of the Syk Activation Switch.,Gradler U, Schwarz D, Dresing V, Musil D, Bomke J, Frech M, Greiner H, Jakel S, Rysiok T, Muller-Pompalla D, Wegener A J Mol Biol. 2012 Nov 12. pii: S0022-2836(12)00879-0. doi:, 10.1016/j.jmb.2012.11.007. PMID:23154170[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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