《Selective dephosphorylation of the threonine183 residue of ERK2 upon對uponkllbKllbL3 engagement in plateletsl3參與血小板ERK2 threonine183殘留選擇性的去磷酸化》由會員上傳分享，免費在線閱讀，更多相關(guān)內(nèi)容在學(xué)術(shù)論文-天天文庫。

1、FEBS26181FEBSLetters521(2002)145^151Selectivedephosphorylationofthethreonine183residueofERK2uponKllbL3engagementinplateletsMarcPawlowskia,AshrafRagabb,Jean-PhilippeRosaa,MarijkeBryckaerta;aU348INSERM,IFR-6CirculationLariboisie're,Ho“pitalLariboisie're,41BvddelaChapelle,75475ParisCedex10,F

2、rancebU563INSERM,IFR30,Ho“pitalPurpan,31059ToulouseCedex,FranceReceived10May2002;accepted14May2002Firstpublishedonline29May2002EditedbyJesusAvilastreamMAPKkinases,MEK1orMEK2[2].TheregulationAbstractThrombin-inducedextracellularsignal-regulatedki-ofERK2activityinvolvesseveraltypesofphosphat

3、asesthatnase2(ERK2)activationisnegativelyregulatedinconditionsofKllbL3integrinengagementandplateletaggregation.Herewedephosphorylateboththreonineandtyrosineactivatingresi-showbyWesternblottingwithantibodiesagainstmono-anddues.Thedual-speci￠cthreonine/tyrosinephosphatasefamily,biphosphoryla

4、tedformsofERK2thatthedephosphorylationofalsocalledtheMAPKphosphatasefamily,includesMKP-1,ERK2byKllbL3engagementaffectsthreonine183andnotPAC-1,MKP-3orMKP-4.Themembersofthisfamilyin-tyrosine185.Additionofapotentserine/threoninephosphataseactivateERK,thepatternofinactivationdependingoncellinh

5、ibitor,okadaicacid(OA),restoredthrombin-inducedthreo-typeandthecytosolicornuclearlocation[3].MKP-3andninephosphorylationofERK2inconditionsofplateletaggrega-MKP-4havebeenshowntobemorespeci￠cforERKthantion,whereasOAhadnoeffectintheabsenceofKllbL3JNKsandp38MAPKs[4^5].MKP-3substrateselectivity

6、engagement.TheseobservationsareconsistentwithKllbL3appearstodependprimarilyontheN-terminal-speci￠cregionengagementactingviaatleastoneserine/threoninephosphatase,183ofthephosphataseandthenonsubstraterecognitiondomainswhichdephosphorylatesthephosphothreonineresidueofERK2.Moreover,asmallamoun

7、t(14%)ofERK2waswithinERK[6^7].Serine/threoninephosphatase1(PP1)andtranslocatedtotheKllbL3-dependentcytoskeleton,mostlyinPP2Ahavebeenalsoshowntoinhibittheactivityoftheamonophosphorylated(i.e.inactive)form,suggestingthatERK1/2pathwaybythedephosphorylationofMEK1/