View source for 3io7


==2-Aminopyrazolo[1,5-a]pyrimidines as potent and selective inhibitors of JAK2==
<StructureSection load='3io7' size='340' side='right' caption='[[3io7]], [[Resolution|resolution]] 2.60&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3io7]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3IO7 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3IO7 FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=1P5:(3S)-1-[6-(2-AMINOPYRAZOLO[1,5-A]PYRIMIDIN-3-YL)PYRIMIDIN-4-YL]-N,N-DIETHYLPIPERIDINE-3-CARBOXAMIDE'>1P5</scene></td></tr>
<tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=PTR:O-PHOSPHOTYROSINE'>PTR</scene></td></tr>
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">JAK2 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 HUMAN])</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=3io7 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3io7 OCA], [http://pdbe.org/3io7 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=3io7 RCSB], [http://www.ebi.ac.uk/pdbsum/3io7 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=3io7 ProSAT]</span></td></tr>
</table>
== Disease ==
[[http://www.uniprot.org/uniprot/JAK2_HUMAN JAK2_HUMAN]] Note=Chromosomal aberrations involving JAK2 are found in both chronic and acute forms of eosinophilic, lymphoblastic and myeloid leukemia. Translocation t(8;9)(p22;p24) with PCM1 links the protein kinase domain of JAK2 to the major portion of PCM1. Translocation t(9;12)(p24;p13) with ETV6.  Defects in JAK2 are a cause of susceptibility to Budd-Chiari syndrome (BDCHS) [MIM:[http://omim.org/entry/600880 600880]]. A syndrome caused by obstruction of hepatic venous outflow involving either the hepatic veins or the terminal segment of the inferior vena cava. Obstructions are generally caused by thrombosis and lead to hepatic congestion and ischemic necrosis. Clinical manifestations observed in the majority of patients include hepatomegaly, right upper quadrant pain and abdominal ascites. Budd-Chiari syndrome is associated with a combination of disease states including primary myeloproliferative syndromes and thrombophilia due to factor V Leiden, protein C deficiency and antithrombin III deficiency. Budd-Chiari syndrome is a rare but typical complication in patients with polycythemia vera.  Defects in JAK2 are a cause of polycythemia vera (PV) [MIM:[http://omim.org/entry/263300 263300]]. A myeloproliferative disorder characterized by abnormal proliferation of all hematopoietic bone marrow elements, erythroid hyperplasia, an absolute increase in total blood volume, but also by myeloid leukocytosis, thrombocytosis and splenomegaly.<ref>PMID:15781101</ref> <ref>PMID:15793561</ref> <ref>PMID:15858187</ref> <ref>PMID:16603627</ref>   Defects in JAK2 gene may be the cause of thrombocythemia type 3 (THCYT3) [MIM:[http://omim.org/entry/614521 614521]]. A myeloproliferative disorder characterized by elevated platelet levels due to sustained proliferation of megakaryocytes, and frequently lead to thrombotic and haemorrhagic complications.<ref>PMID:16325696</ref> <ref>PMID:22397670</ref>   Defects in JAK2 are a cause of myelofibrosis (MYELOF) [MIM:[http://omim.org/entry/254450 254450]]. Myelofibrosis is a disorder characterized by replacement of the bone marrow by fibrous tissue, occurring in association with a myeloproliferative disorder. Clinical manifestations may include anemia, pallor, splenomegaly, hypermetabolic state, petechiae, ecchymosis, bleeding, lymphadenopathy, hepatomegaly, portal hypertension.  Defects in JAK2 are a cause of acute myelogenous leukemia (AML) [MIM:[http://omim.org/entry/601626 601626]]. AML is a malignant disease in which hematopoietic precursors are arrested in an early stage of development.<ref>PMID:16247455</ref>  
== Function ==
[[http://www.uniprot.org/uniprot/JAK2_HUMAN JAK2_HUMAN]] Non-receptor tyrosine kinase involved in various processes such as cell growth, development, differentiation or histone modifications. Mediates essential signaling events in both innate and adaptive immunity. In the cytoplasm, plays a pivotal role in signal transduction via its association with type I receptors such as growth hormone (GHR), prolactin (PRLR), leptin (LEPR), erythropoietin (EPOR), thrombopoietin (THPO); or type II receptors including IFN-alpha, IFN-beta, IFN-gamma and multiple interleukins. Following ligand-binding to cell surface receptors, phosphorylates specific tyrosine residues on the cytoplasmic tails of the receptor, creating docking sites for STATs proteins. Subsequently, phosphorylates the STATs proteins once they are recruited to the receptor. Phosphorylated STATs then form homodimer or heterodimers and translocate to the nucleus to activate gene transcription. For example, cell stimulation with erythropoietin (EPO) during erythropoiesis leads to JAK2 autophosphorylation, activation, and its association with erythropoietin receptor (EPOR) that becomes phosphorylated in its cytoplasmic domain. Then, STAT5 (STAT5A or STAT5B) is recruited, phosphorylated and activated by JAK2. Once activated, dimerized STAT5 translocates into the nucleus and promotes the transcription of several essential genes involved in the modulation of erythropoiesis. In addition, JAK2 mediates angiotensin-2-induced ARHGEF1 phosphorylation. Plays a role in cell cycle by phosphorylating CDKN1B. Cooperates with TEC through reciprocal phosphorylation to mediate cytokine-driven activation of FOS transcription. In the nucleus, plays a key role in chromatin by specifically mediating phosphorylation of 'Tyr-41' of histone H3 (H3Y41ph), a specific tag that promotes exclusion of CBX5 (HP1 alpha) from chromatin.<ref>PMID:12023369</ref> <ref>PMID:19783980</ref> <ref>PMID:20098430</ref> <ref>PMID:21423214</ref>  
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/io/3io7_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=3io7 ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Constitutive activation of the EPO/JAK2 signaling cascade has recently been implicated in a variety of myeloproliferative disorders including polycythemia vera, essential thrombocythemia and myelofibrosis. In an effort to uncover therapeutic potential of blocking the EPO/JAK2 signaling cascade, we sought to discover selective inhibitors that block the kinase activity of JAK2. Herein, we describe the discovery and structure based optimization of a novel series of 2-amino-pyrazolo[1,5-a]pyrimidines that exhibit potent inhibition of JAK2.

2-Aminopyrazolo[1,5-a]pyrimidines as potent and selective inhibitors of JAK2.,Ledeboer MW, Pierce AC, Duffy JP, Gao H, Messersmith D, Salituro FG, Nanthakumar S, Come J, Zuccola HJ, Swenson L, Shlyakter D, Mahajan S, Hoock T, Fan B, Tsai WJ, Kolaczkowski E, Carrier S, Hogan JK, Zessis R, Pazhanisamy S, Bennani YL Bioorg Med Chem Lett. 2009 Dec 1;19(23):6529-33. Epub 2009 Oct 24. PMID:19857967<ref>PMID:19857967</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 3io7" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Human]]
[[Category: Non-specific protein-tyrosine kinase]]
[[Category: Ledeboer, M W]]
[[Category: Pierce, A C]]
[[Category: Zuccola, H J]]
[[Category: Atp-binding]]
[[Category: Chromosomal rearrangement]]
[[Category: Disease mutation]]
[[Category: Inhibitor]]
[[Category: Jak2]]
[[Category: Janus kinase]]
[[Category: Kinase]]
[[Category: Membrane]]
[[Category: Nucleotide-binding]]
[[Category: Phosphoprotein]]
[[Category: Polymorphism]]
[[Category: Proto-oncogene]]
[[Category: Sh2 domain]]
[[Category: Transferase]]
[[Category: Tyrosine-protein kinase]]