View source for 9lnr


==Crystal structure of SKLB-D18 with ERK2==
<StructureSection load='9lnr' size='340' side='right'caption='[[9lnr]], [[Resolution|resolution]] 2.10&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[9lnr]] is a 1 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=9LNR OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=9LNR 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]] 2.1&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=A1EKR:4-[5-chloranyl-2-[[3-[(dimethylamino)methyl]phenyl]amino]pyrimidin-4-yl]-~{N}-morpholin-4-yl-thiophene-2-carboxamide'>A1EKR</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</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=9lnr FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=9lnr OCA], [https://pdbe.org/9lnr PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=9lnr RCSB], [https://www.ebi.ac.uk/pdbsum/9lnr PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=9lnr ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/MK01_HUMAN MK01_HUMAN] Serine/threonine kinase which acts as an essential component of the MAP kinase signal transduction pathway. MAPK1/ERK2 and MAPK3/ERK1 are the 2 MAPKs which play an important role in the MAPK/ERK cascade. They participate also in a signaling cascade initiated by activated KIT and KITLG/SCF. Depending on the cellular context, the MAPK/ERK cascade mediates diverse biological functions such as cell growth, adhesion, survival and differentiation through the regulation of transcription, translation, cytoskeletal rearrangements. The MAPK/ERK cascade plays also a role in initiation and regulation of meiosis, mitosis, and postmitotic functions in differentiated cells by phosphorylating a number of transcription factors. About 160 substrates have already been discovered for ERKs. Many of these substrates are localized in the nucleus, and seem to participate in the regulation of transcription upon stimulation. However, other substrates are found in the cytosol as well as in other cellular organelles, and those are responsible for processes such as translation, mitosis and apoptosis. Moreover, the MAPK/ERK cascade is also involved in the regulation of the endosomal dynamics, including lysosome processing and endosome cycling through the perinuclear recycling compartment (PNRC); as well as in the fragmentation of the Golgi apparatus during mitosis. The substrates include transcription factors (such as ATF2, BCL6, ELK1, ERF, FOS, HSF4 or SPZ1), cytoskeletal elements (such as CANX, CTTN, GJA1, MAP2, MAPT, PXN, SORBS3 or STMN1), regulators of apoptosis (such as BAD, BTG2, CASP9, DAPK1, IER3, MCL1 or PPARG), regulators of translation (such as EIF4EBP1) and a variety of other signaling-related molecules (like ARHGEF2, DCC, FRS2 or GRB10). Protein kinases (such as RAF1, RPS6KA1/RSK1, RPS6KA3/RSK2, RPS6KA2/RSK3, RPS6KA6/RSK4, SYK, MKNK1/MNK1, MKNK2/MNK2, RPS6KA5/MSK1, RPS6KA4/MSK2, MAPKAPK3 or MAPKAPK5) and phosphatases (such as DUSP1, DUSP4, DUSP6 or DUSP16) are other substrates which enable the propagation the MAPK/ERK signal to additional cytosolic and nuclear targets, thereby extending the specificity of the cascade. May play a role in the spindle assembly checkpoint.<ref>PMID:7588608</ref> <ref>PMID:8622688</ref> <ref>PMID:9480836</ref> <ref>PMID:9687510</ref> <ref>PMID:9649500</ref> <ref>PMID:9596579</ref> <ref>PMID:10637505</ref> <ref>PMID:10617468</ref> <ref>PMID:11154262</ref> <ref>PMID:12110590</ref> <ref>PMID:12356731</ref> <ref>PMID:12974390</ref> <ref>PMID:12794087</ref> <ref>PMID:12792650</ref> <ref>PMID:15184391</ref> <ref>PMID:15241487</ref> <ref>PMID:15952796</ref> <ref>PMID:15616583</ref> <ref>PMID:15788397</ref> <ref>PMID:15664191</ref> <ref>PMID:16581800</ref> <ref>PMID:19879846</ref> <ref>PMID:19265199</ref>   Acts as a transcriptional repressor. Binds to a [GC]AAA[GC] consensus sequence. Repress the expression of interferon gamma-induced genes. Seems to bind to the promoter of CCL5, DMP1, IFIH1, IFITM1, IRF7, IRF9, LAMP3, OAS1, OAS2, OAS3 and STAT1. Transcriptional activity is independent of kinase activity.<ref>PMID:7588608</ref> <ref>PMID:8622688</ref> <ref>PMID:9480836</ref> <ref>PMID:9687510</ref> <ref>PMID:9649500</ref> <ref>PMID:9596579</ref> <ref>PMID:10637505</ref> <ref>PMID:10617468</ref> <ref>PMID:11154262</ref> <ref>PMID:12110590</ref> <ref>PMID:12356731</ref> <ref>PMID:12974390</ref> <ref>PMID:12794087</ref> <ref>PMID:12792650</ref> <ref>PMID:15184391</ref> <ref>PMID:15241487</ref> <ref>PMID:15952796</ref> <ref>PMID:15616583</ref> <ref>PMID:15788397</ref> <ref>PMID:15664191</ref> <ref>PMID:16581800</ref> <ref>PMID:19879846</ref> <ref>PMID:19265199</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Despite significant advancements in kinase-targeted therapy, the emergence of acquired drug resistance to targets such as KRAS and MEK remains a challenge. Extracellular-regulated kinase 1/2 (ERK1/2), positioned at the terminus of this pathway, is highly conserved and less susceptible to mutations, thereby garnering attention as a crucial therapeutical target. However, attempts to use monotherapies that target ERK1/2 have achieved only limited clinical success, mainly due to the issues of limited efficacy and the emergence of drug resistance. Herein, we present a proof of concept that extracellular-regulated kinase 5 (ERK5) acts as a compensatory pathway after ERK1/2 inhibition in triple-negative breast cancer (TNBC). By utilizing the principle of polypharmacology, we computationally designed SKLB-D18, a first-in-class molecule that selectively targets ERK1/2 and ERK5, with nanomolar potency and high specificity for both targets. SKLB-D18 demonstrated excellent tolerability in mice and demonstrated superior in vivo anti-tumor efficacy, not only exceeding the existing clinical ERK1/2 inhibitor BVD-523, but also the combination regimen of BVD-523 and the ERK5 inhibitor XMD8-92. Mechanistically, we showed that SKLB-D18, as an autophagy agonist, played a role in mammalian target of rapamycin (mTOR)/70 ribosomal protein S6 kinase (p70S6K) and nuclear receptor coactivator 4 (NCOA4)-mediated ferroptosis, which may mitigate multidrug resistance.

A first-in-class selective inhibitor of ERK1/2 and ERK5 overcomes drug resistance with a single-molecule strategy.,Xiao H, Wang A, Shuai W, Qian Y, Wu C, Wang X, Yang P, Sun Q, Wang G, Ouyang L, Sun Q Signal Transduct Target Ther. 2025 Feb 20;10(1):70. doi: , 10.1038/s41392-025-02169-z. PMID:39979271<ref>PMID:39979271</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 9lnr" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Sun Q]]
[[Category: Xiao H]]