View source for 3fup


==Crystal structures of JAK1 and JAK2 inhibitor complexes==
<StructureSection load='3fup' size='340' side='right'caption='[[3fup]], [[Resolution|resolution]] 2.40&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3fup]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3FUP OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3FUP FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.4&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MI1:3-{(3R,4R)-4-METHYL-3-[METHYL(7H-PYRROLO[2,3-D]PYRIMIDIN-4-YL)AMINO]PIPERIDIN-1-YL}-3-OXOPROPANENITRILE'>MI1</scene>, <scene name='pdbligand=PTR:O-PHOSPHOTYROSINE'>PTR</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=3fup FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3fup OCA], [https://pdbe.org/3fup PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3fup RCSB], [https://www.ebi.ac.uk/pdbsum/3fup PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3fup ProSAT]</span></td></tr>
</table>
== Disease ==
[https://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:[https://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:[https://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:[https://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:[https://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:[https://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 ==
[https://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/fu/3fup_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=3fup ConSurf].
<div style="clear:both"></div>
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== Publication Abstract from PubMed ==
The Janus kinases (JAKs) are a pivotal family of protein tyrosine kinases (PTKs) that play prominent roles in numerous cytokine signaling pathways, with aberrant JAK activity associated with a variety of hematopoietic malignancies, cardiovascular diseases and immune-related disorders. Whereas the structures of the JAK2 and JAK3 PTK domains have been determined, the structure of the JAK1 PTK domain is unknown. Here, we report the high-resolution crystal structures of the "active form" of the JAK1 PTK domain in complex with two JAK inhibitors, a tetracyclic pyridone 2-t-butyl-9-fluoro-3,6-dihydro-7H-benz[h]-imidaz[4,5-f]isoquinoline-7-one (CMP6) and (3R,4R)-3-[4-methyl-3-[N-methyl-N-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)amino]p iperidin-1-yl]-3-oxopropionitrile (CP-690,550), and compare them with the corresponding JAK2 PTK inhibitor complexes. Both inhibitors bound in a similar manner to JAK1, namely buried deep within a constricted ATP-binding site, thereby providing a basis for the potent inhibition of JAK1. As expected, the mode of inhibitor binding in JAK1 was very similar to that observed in JAK2, highlighting the challenges in developing JAK-specific inhibitors that target the ATP-binding site. Nevertheless, differences surrounding the JAK1 and JAK2 ATP-binding sites were apparent, thereby providing a platform for the rational design of JAK2- and JAK1-specific inhibitors.

Dissecting specificity in the Janus kinases: the structures of JAK-specific inhibitors complexed to the JAK1 and JAK2 protein tyrosine kinase domains.,Williams NK, Bamert RS, Patel O, Wang C, Walden PM, Wilks AF, Fantino E, Rossjohn J, Lucet IS J Mol Biol. 2009 Mar 20;387(1):219-32. Epub 2009 Jan 29. PMID:19361440<ref>PMID:19361440</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 3fup" style="background-color:#fffaf0;"></div>

==See Also==
*[[Janus kinase 3D structures|Janus kinase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Bamert RS]]
[[Category: Fantino E]]
[[Category: Lucet IS]]
[[Category: Patel O]]
[[Category: Rossjohn J]]
[[Category: Williams NK]]