Featured Publications
Catalytic in vivo protein knockdown by small-molecule PROTACs
Bondeson DP, Mares A, Smith IE, Ko E, Campos S, Miah AH, Mulholland KE, Routly N, Buckley DL, Gustafson JL, Zinn N, Grandi P, Shimamura S, Bergamini G, Faelth-Savitski M, Bantscheff M, Cox C, Gordon DA, Willard RR, Flanagan JJ, Casillas LN, Votta BJ, den Besten W, Famm K, Kruidenier L, Carter PS, Harling JD, Churcher I, Crews CM. Catalytic in vivo protein knockdown by small-molecule PROTACs. Nature Chemical Biology 2015, 11: 611-617. PMID: 26075522, PMCID: PMC4629852, DOI: 10.1038/nchembio.1858.Peer-Reviewed Original ResearchMeSH KeywordsAnimalsAntineoplastic AgentsBinding SitesBiocatalysisBreast NeoplasmsFemaleHumansMCF-7 CellsMiceModels, MolecularMolecular Targeted TherapyNeoplasm ProteinsNeoplasm TransplantationProteasome Endopeptidase ComplexProtein BindingProteolysisReceptor-Interacting Protein Serine-Threonine Kinase 2Receptors, EstrogenSmall Molecule LibrariesUbiquitinUbiquitinationVon Hippel-Lindau Tumor Suppressor Protein
2021
BET proteolysis targeted chimera-based therapy of novel models of Richter Transformation-diffuse large B-cell lymphoma
Fiskus W, Mill CP, Perera D, Birdwell C, Deng Q, Yang H, Lara BH, Jain N, Burger J, Ferrajoli A, Davis JA, Saenz DT, Jin W, Coarfa C, Crews CM, Green MR, Khoury JD, Bhalla KN. BET proteolysis targeted chimera-based therapy of novel models of Richter Transformation-diffuse large B-cell lymphoma. Leukemia 2021, 35: 2621-2634. PMID: 33654205, PMCID: PMC8410602, DOI: 10.1038/s41375-021-01181-w.Peer-Reviewed Original ResearchMeSH KeywordsAdenineAnimalsAntineoplastic Combined Chemotherapy ProtocolsApoptosisBiomarkers, TumorBridged Bicyclo Compounds, HeterocyclicCell ProliferationCell Transformation, NeoplasticGene Expression Regulation, NeoplasticHumansLymphoma, Large B-Cell, DiffuseMicePiperidinesProteinsProteolysisSulfonamidesTumor Cells, CulturedXenograft Model Antitumor AssaysConceptsLarge B-cell lymphomaB-cell lymphomaRichter transformationBET protein inhibitorLymphoma burdenImproved survivalCombination therapyC-Myc levelsEffective therapyNovel therapiesCell lymphomaXenograft modelProtein inhibitorTherapyBET inhibitorsProtein expressionCLLGenetic alterationsLymphomaInhibitorsIRF4Single-cell RNA-seqHuman modelCRISPR knockoutCellsMutant-selective degradation by BRAF-targeting PROTACs
Alabi S, Jaime-Figueroa S, Yao Z, Gao Y, Hines J, Samarasinghe KTG, Vogt L, Rosen N, Crews CM. Mutant-selective degradation by BRAF-targeting PROTACs. Nature Communications 2021, 12: 920. PMID: 33568647, PMCID: PMC7876048, DOI: 10.1038/s41467-021-21159-7.Peer-Reviewed Original ResearchConceptsInhibitor-based therapyBRAF inhibitor-based therapiesBRAF missense mutationsCancer cell growthBRAF V600Current treatmentNew therapiesTherapeutic windowXenograft modelBRAF mutantMutant BRAFVivo efficacyDrug modalitiesRaf family membersProteolysis targeting chimera (PROTAC) technologyTherapyBRAFMissense mutationsFamily membersBRAFWTCell growthDegree of selectivityInactivated conformationPatientsV600
2017
BET protein proteolysis targeting chimera (PROTAC) exerts potent lethal activity against mantle cell lymphoma cells
Sun B, Fiskus W, Qian Y, Rajapakshe K, Raina K, Coleman KG, Crew AP, Shen A, Saenz DT, Mill CP, Nowak AJ, Jain N, Zhang L, Wang M, Khoury JD, Coarfa C, Crews CM, Bhalla KN. BET protein proteolysis targeting chimera (PROTAC) exerts potent lethal activity against mantle cell lymphoma cells. Leukemia 2017, 32: 343-352. PMID: 28663582, DOI: 10.1038/leu.2017.207.Peer-Reviewed Original ResearchConceptsMantle cell lymphoma cellsMCL cellsCell lymphoma cellsARV-825ARV-771Lymphoma cellsGreater survival improvementSuperior preclinical activityCDK4/6 inhibitor palbociclibNuclear factor-κB (NF-κB) target genesExtraterminal protein inhibitorSurvival improvementInhibitor palbociclibPreclinical activityCDKN1A/p21Inhibitor treatmentSuperior pharmacological propertiesVivo growthCyclin D1Pharmacological propertiesProtein expressionMore apoptosisVivo evaluationIncomplete inhibitionC-MycNovel BET protein proteolysis-targeting chimera exerts superior lethal activity than bromodomain inhibitor (BETi) against post-myeloproliferative neoplasm secondary (s) AML cells
Saenz DT, Fiskus W, Qian Y, Manshouri T, Rajapakshe K, Raina K, Coleman KG, Crew AP, Shen A, Mill CP, Sun B, Qiu P, Kadia TM, Pemmaraju N, DiNardo C, Kim MS, Nowak AJ, Coarfa C, Crews CM, Verstovsek S, Bhalla KN. Novel BET protein proteolysis-targeting chimera exerts superior lethal activity than bromodomain inhibitor (BETi) against post-myeloproliferative neoplasm secondary (s) AML cells. Leukemia 2017, 31: 1951-1961. PMID: 28042144, PMCID: PMC5537055, DOI: 10.1038/leu.2016.393.Peer-Reviewed Original ResearchConceptsBET protein inhibitorARV-825Messenger RNAReverse phase protein arrayPhase protein arrayRNA-seqHematopoietic progenitor cellsNormal hematopoietic progenitor cellsBET proteinsE3 ubiquitin ligase cereblonLevels of p21Extraterminal (BET) proteinsBcl-xLBromodomain inhibitorsC-MycJAK inhibitor ruxolitinibBRD4Protein arraysProgenitor cellsProtein expressionHEL92.1.7 cellsImproved survivalLeukemia burdenNSG miceProfound depletion
2013
Posttranslational protein knockdown coupled to receptor tyrosine kinase activation with phosphoPROTACs
Hines J, Gough JD, Corson TW, Crews CM. Posttranslational protein knockdown coupled to receptor tyrosine kinase activation with phosphoPROTACs. Proceedings Of The National Academy Of Sciences Of The United States Of America 2013, 110: 8942-8947. PMID: 23674677, PMCID: PMC3670320, DOI: 10.1073/pnas.1217206110.Peer-Reviewed Original ResearchMeSH KeywordsAmino Acid SequenceAnalysis of VarianceAnimalsChromatography, High Pressure LiquidEnzyme ActivationFemaleGene Knockdown TechniquesHumansImmunoblottingMCF-7 CellsMiceMolecular Sequence DataMolecular StructurePC12 CellsPhosphatidylinositol 3-KinasesPhosphorylationProtein Processing, Post-TranslationalProteolysisRatsReceptor Protein-Tyrosine KinasesReceptor, ErbB-3Receptor, Fibroblast Growth Factor, Type 2Receptor, trkASignal TransductionStreptavidinVon Hippel-Lindau Tumor Suppressor ProteinConceptsGrowth factor receptorProtein knockdownFibroblast growth factor receptor substrateVon Hippel-Lindau proteinSpecific receptor tyrosine kinasesKinase-mediated phosphorylationReceptor tyrosine kinase pathwaysFactor receptorKinase signal pathwayTyrosine kinase activationReceptor tyrosine kinasesTyrosine kinase pathwayConditional degradationPhosphorylation sequenceKinase pathwayReceptor substrateKinase activationNucleic acid-based strategiesLindau proteinTarget protein knockdownSpecific proteinsTyrosine kinaseCell-type selectivityNerve growth factor receptorKnockdown
2011
Small-molecule hydrophobic tagging–induced degradation of HaloTag fusion proteins
Neklesa TK, Tae HS, Schneekloth AR, Stulberg MJ, Corson TW, Sundberg TB, Raina K, Holley SA, Crews CM. Small-molecule hydrophobic tagging–induced degradation of HaloTag fusion proteins. Nature Chemical Biology 2011, 7: 538-543. PMID: 21725302, PMCID: PMC3139752, DOI: 10.1038/nchembio.597.Peer-Reviewed Original Research
2003
Selective inhibitors of the osteoblast proteasome stimulate bone formation in vivo and in vitro
Garrett IR, Chen D, Gutierrez G, Zhao M, Escobedo A, Rossini G, Harris SE, Gallwitz W, Kim KB, Hu S, Crews CM, Mundy GR. Selective inhibitors of the osteoblast proteasome stimulate bone formation in vivo and in vitro. Journal Of Clinical Investigation 2003, 111: 1771-1782. PMID: 12782679, PMCID: PMC156102, DOI: 10.1172/jci16198.Peer-Reviewed Original ResearchMeSH KeywordsAnimalsBlotting, NorthernBlotting, WesternBone and BonesBone DevelopmentBone Morphogenetic Protein 2Bone Morphogenetic Protein 4Bone Morphogenetic ProteinsCarrier ProteinsCell DivisionCell LineCysteine EndopeptidasesDNADose-Response Relationship, DrugEnzyme-Linked Immunosorbent AssayGenetic VectorsHumansLuciferasesMiceMice, Inbred ICRMultienzyme ComplexesOrgan Culture TechniquesOsteoblastsPromoter Regions, GeneticProteasome Endopeptidase ComplexProteinsRNA, MessengerSkullTranscription, GeneticTransfectionTransforming Growth Factor betaConceptsUbiquitin-proteasome pathwayBMP-4BMP-2Osteoblast differentiationBMP-6 mRNA expressionUbiquitin-proteasome machineryEffect of nogginCatalytic beta subunitsProteasome inhibitorsBMP-2 gene expressionBone morphogenetic protein-2Drosophila homologueMorphogenetic protein-2Gli3 proteinGene expressionBeta subunitProteolytic processingProtein 2Bone formationDifferent inhibitorsEndogenous inhibitorOsteoblastic cellsProteasomeNogginInhibitor-1
2001
Cells adapted to the proteasome inhibitor 4-hydroxy- 5-iodo-3-nitrophenylacetyl-Leu-Leu-leucinal-vinyl sulfone require enzymatically active proteasomes for continued survival
Princiotta M, Schubert U, Chen W, Bennink J, Myung J, Crews C, Yewdell J. Cells adapted to the proteasome inhibitor 4-hydroxy- 5-iodo-3-nitrophenylacetyl-Leu-Leu-leucinal-vinyl sulfone require enzymatically active proteasomes for continued survival. Proceedings Of The National Academy Of Sciences Of The United States Of America 2001, 98: 513-518. PMID: 11149939, PMCID: PMC14618, DOI: 10.1073/pnas.98.2.513.Peer-Reviewed Original ResearchMeSH KeywordsAmino Acid Chloromethyl KetonesAminopeptidasesAnimalsAntigen PresentationAntigensBoronic AcidsBortezomibCD8-Positive T-LymphocytesCell SurvivalCysteine EndopeptidasesDipeptidyl-Peptidases and Tripeptidyl-PeptidasesDrug ResistanceEndopeptidasesEnzyme ActivationH-2 AntigensLeupeptinsLymphoma, T-CellMiceMultienzyme ComplexesNeoplasm ProteinsOligopeptidesPeptide FragmentsPhenolsProtease InhibitorsProteasome Endopeptidase ComplexProtein Processing, Post-TranslationalPyrazinesSelection, GeneticSerine EndopeptidasesSulfonesThymus NeoplasmsTumor Cells, CulturedTumor Suppressor Protein p53TyramineUbiquitinsConceptsII activityLarge proteolytic complexSpecific proteasome inhibitorInhibitor 4Degradation of p53Ala-AlaProteolytic complexPolyubiquitinated proteinsLeu-LeuProteolytic functionActive proteasomesPrimary proteaseProperties of cellsProteolytic systemProteasomeSpecific inhibitorMajor histocompatibility complexPhe-chloromethylketoneProteasome inhibitorsThe anti-inflammatory natural product parthenolide from the medicinal herb Feverfew directly binds to and inhibits IκB kinase
Kwok B, Koh B, Ndubuisi M, Elofsson M, Crews C. The anti-inflammatory natural product parthenolide from the medicinal herb Feverfew directly binds to and inhibits IκB kinase. Cell Chemical Biology 2001, 8: 759-766. PMID: 11514225, DOI: 10.1016/s1074-5521(01)00049-7.Peer-Reviewed Original ResearchConceptsAnti-inflammatory activityHerb feverfewPro-inflammatory signaling pathwaysDirect molecular targetVivo anti-inflammatory activityAnti-inflammatory propertiesAnti-inflammatory agentsCytokine-mediated stimulationCytokine-mediated signalingIkappaB kinase betaSesquiterpene lactone parthenolidePharmaceutical interventionsIκB kinaseMolecular targetsNatural product parthenolideKinase betaParthenolideCysteine 179Signaling pathwaysPossible molecular basisIntracellular signaling processesAttractive targetIKK complexMolecular mechanismsAlpha-methylene gamma-lactone moiety
2000
The antiangiogenic agent TNP-470 requires p53 and p21CIP/WAF for endothelial cell growth arrest
Yeh J, Mohan R, Crews C. The antiangiogenic agent TNP-470 requires p53 and p21CIP/WAF for endothelial cell growth arrest. Proceedings Of The National Academy Of Sciences Of The United States Of America 2000, 97: 12782-12787. PMID: 11070090, PMCID: PMC18841, DOI: 10.1073/pnas.97.23.12782.Peer-Reviewed Original ResearchMeSH KeywordsAdultAngiogenesis InhibitorsAnimalsCell CycleCell DivisionCells, CulturedCorneal NeovascularizationCyclin-Dependent Kinase Inhibitor p21Cyclin-Dependent KinasesCyclinsCyclohexanesEndothelium, VascularGene ExpressionHumansMiceMice, KnockoutNuclear ProteinsO-(Chloroacetylcarbamoyl)fumagillolProto-Oncogene ProteinsProto-Oncogene Proteins c-mdm2SesquiterpenesTumor Suppressor Protein p53ConceptsTNP-470Endothelial cellsAntiangiogenic agent TNP-470Subsequent growth arrestGrowth arrestCyclin-dependent kinase inhibitorAntiangiogenic strategiesPrimary endothelial cellsEndothelial cell growth arrestP21CIP/WAFEndothelial cell cycleCell growth arrestKinase inhibitorsAntiangiogenic activityCell cycle regulatorsAngiogenesis assayCytostatic activityP53 activationMiceCritical cell cycle regulatorsCycle regulatorsUnique mechanismAdult fibroblastsCell-type specificityArrestThe Selective Proteasome Inhibitors Lactacystin and Epoxomicin Can Be Used to Either Up- or Down-Regulate Antigen Presentation at Nontoxic Doses
Schwarz K, de Giuli R, Schmidtke G, Kostka S, van den Broek M, Kim K, Crews C, Kraft R, Groettrup M. The Selective Proteasome Inhibitors Lactacystin and Epoxomicin Can Be Used to Either Up- or Down-Regulate Antigen Presentation at Nontoxic Doses. The Journal Of Immunology 2000, 164: 6147-6157. PMID: 10843664, PMCID: PMC2507740, DOI: 10.4049/jimmunol.164.12.6147.Peer-Reviewed Original ResearchMeSH KeywordsAcetylcysteineAmino Acid SequenceAnimalsAntigen PresentationAntigens, ViralApoptosisCell DivisionCell LineCysteine EndopeptidasesCysteine Proteinase InhibitorsDose-Response Relationship, ImmunologicDown-RegulationGlycoproteinsHumansHybridomasHydrolysisLymphocyte ActivationLymphocytic choriomeningitis virusMiceMice, Inbred BALB CMice, Inbred C57BLMolecular Sequence DataMultienzyme ComplexesNucleoproteinsOligopeptidesPeptide FragmentsProteasome Endopeptidase ComplexT-Lymphocytes, CytotoxicTumor Cells, CulturedUbiquitinsUp-RegulationViral ProteinsConceptsAg presentationProteasome inhibitor lactacystinCellular proliferationProteasome activitySelective inhibitionMHC class IDose-dependent mannerTransplant rejectionAutoimmune diseasesMouse CMVAntigen presentationMost MHC class INontoxic dosesChymotrypsin-like activityClass ISelective proteasome inhibitor lactacystinApoptosis inductionMicroM lactacystinViral proteinsPresentationInhibitionComplete inhibitionLactacystinVivoProliferation
1999
Towards subunit-specific proteasome inhibitors: synthesis and evaluation of peptide α', β'-epoxyketones
Elofsson M, Splittgerber U, Myung J, Mohan R, Crews C. Towards subunit-specific proteasome inhibitors: synthesis and evaluation of peptide α', β'-epoxyketones. Cell Chemical Biology 1999, 6: 811-822. PMID: 10574782, DOI: 10.1016/s1074-5521(99)80128-8.Peer-Reviewed Original ResearchMeSH KeywordsAnimalsAortaCattleCell DivisionCells, CulturedChymotrypsinCysteine EndopeptidasesCysteine Proteinase InhibitorsDrug DesignEndothelium, VascularEpoxy CompoundsGlutamatesIndicators and ReagentsIrritantsKineticsMacromolecular SubstancesMiceMolecular ConformationMultienzyme ComplexesPeptidesProteasome Endopeptidase ComplexTrypsinConceptsCatalytic activityMolecular probesAcetylated peptidesExcellent selectivityPotent proteasome inhibitorVivo anti-inflammatory activityMost compoundsMajor catalytic activityChymotrypsin-like activityPeptide αAromatic amino acidsEpoxyketonesAminoP2-P4Multicatalytic protease complexPeptidesAnti-inflammatory activitySelectivityProbeLarge multicatalytic protease complexesProteasome inhibitorsAmino acidsSynthesisCompoundsComplexesTotal synthesis of the-potent proteasome inhibitor epoxomicin: a useful tool for understanding proteasome biology
Sin N, Kim K, Elofsson M, Meng L, Auth H, Kwok B, Crews C. Total synthesis of the-potent proteasome inhibitor epoxomicin: a useful tool for understanding proteasome biology. Bioorganic & Medicinal Chemistry Letters 1999, 9: 2283-2288. PMID: 10465562, DOI: 10.1016/s0960-894x(99)00376-5.Peer-Reviewed Original ResearchEponemycin exerts its antitumor effect through the inhibition of proteasome function.
Meng L, Kwok BH, Sin N, Crews CM. Eponemycin exerts its antitumor effect through the inhibition of proteasome function. Cancer Research 1999, 59: 2798-801. PMID: 10383134.Peer-Reviewed Original ResearchConceptsProteasome inhibitionCyclin-dependent kinase inhibitorNovel chemotherapeutic strategiesPharmacological interventionsAntitumor effectsPossible cancer therapySubunits LMP2Chemotherapeutic strategiesKinase inhibitorsCellular morphological changesCell cycle progressionCancer therapyCycle progressionInhibitionProteasome functionMorphological changesKey regulatory proteinsProteasomal subunitsTherapy
1993
Raf-1 forms a stable complex with Mek1 and activates Mek1 by serine phosphorylation.
Huang W, Alessandrini A, Crews CM, Erikson RL. Raf-1 forms a stable complex with Mek1 and activates Mek1 by serine phosphorylation. Proceedings Of The National Academy Of Sciences Of The United States Of America 1993, 90: 10947-10951. PMID: 8248196, PMCID: PMC47898, DOI: 10.1073/pnas.90.23.10947.Peer-Reviewed Original ResearchMeSH KeywordsAnimalsEnzyme ActivationIn Vitro TechniquesMacromolecular SubstancesMAP Kinase Kinase 1MiceMitogen-Activated Protein Kinase KinasesPhosphorylationPhosphoserineProtein BindingProtein Serine-Threonine KinasesProtein-Tyrosine KinasesProto-Oncogene ProteinsProto-Oncogene Proteins c-rafRecombinant ProteinsMEK2 is a kinase related to MEK1 and is differentially expressed in murine tissues.
Brott BK, Alessandrini A, Largaespada DA, Copeland NG, Jenkins NA, Crews CM, Erikson RL. MEK2 is a kinase related to MEK1 and is differentially expressed in murine tissues. Molecular Cancer Research 1993, 4: 921-9. PMID: 8297798.Peer-Reviewed Original ResearchMeSH KeywordsAmino Acid SequenceAmino AcidsAnimalsAnimals, NewbornBase SequenceBrainChromosome MappingCloning, MolecularFemaleGene Expression RegulationMaleMAP Kinase Kinase 1MAP Kinase Kinase 2MiceMitogen-Activated Protein Kinase KinasesMolecular Sequence DataNucleic Acid HybridizationProtein Serine-Threonine KinasesProtein-Tyrosine KinasesRecombinant ProteinsRNA, MessengerSequence AnalysisConceptsERK-1Dual-specificity kinaseMurine chromosome 9Substantial sequence homologyErk/MAPMultigene familyLow expression levelsMEK2 proteinsAdult mouse brainSequence homologyAmino terminusDifferent genesERK-2MEK2MEK1Northern analysisChromosome 9Complementary DNAMurine tissuesExpression levelsKinase
1992
The Primary Structure of MEK, a Protein Kinase that Phosphorylates the ERK Gene Product
Crews C, Alessandrini A, Erikson R. The Primary Structure of MEK, a Protein Kinase that Phosphorylates the ERK Gene Product. Science 1992, 258: 478-480. PMID: 1411546, DOI: 10.1126/science.1411546.Peer-Reviewed Original ResearchMeSH KeywordsAmino Acid SequenceAnimalsBase SequenceCalcium-Calmodulin-Dependent Protein KinasesGene ExpressionMAP Kinase Kinase 1MiceMitogen-Activated Protein Kinase KinasesMolecular Sequence DataPhosphorylationProtein KinasesProtein Serine-Threonine KinasesProtein-Tyrosine KinasesProteinsRNA, MessengerSequence AlignmentConceptsExtracellular signal-regulated kinaseProtein kinaseMAP kinaseGene productsCritical protein kinaseSignal-regulated kinaseComplementary DNA sequenceMEK genesExtracellular signalsERK kinaseMultiple biochemical signalsDNA sequencesBiochemical signalsPrimary structureKinaseAmino acidsEnzymatic activityGenesMurine brainSequenceSchizosaccharomycesMEK1MEKThreonineProteinPurification of a murine protein-tyrosine/threonine kinase that phosphorylates and activates the Erk-1 gene product: relationship to the fission yeast byr1 gene product.
Crews CM, Erikson RL. Purification of a murine protein-tyrosine/threonine kinase that phosphorylates and activates the Erk-1 gene product: relationship to the fission yeast byr1 gene product. Proceedings Of The National Academy Of Sciences Of The United States Of America 1992, 89: 8205-8209. PMID: 1381507, PMCID: PMC49886, DOI: 10.1073/pnas.89.17.8205.Peer-Reviewed Original ResearchMeSH KeywordsAmino Acid SequenceAnimalsEnzyme ActivationFungal ProteinsGenesMiceMitogen-Activated Protein Kinase 3Mitogen-Activated Protein KinasesMolecular Sequence DataPeptide FragmentsPhosphorylationPhosphoserinePhosphothreoninePhosphotyrosineProtein KinasesRecombinant ProteinsSequence AlignmentTyrosineConceptsGene productsProtein kinaseSerine/threonine phosphatase 2AMyelin basic protein kinaseProtein tyrosine phosphatase 1B.MAPK/ERK kinaseSignal transduction mechanismsPossible signal transduction mechanismsERK-1 proteinSte7 genePhosphatase 2AThreonine kinaseERK kinaseERK-1Tyrosine residuesSequence analysisKinaseTransduction mechanismsMEKTrypsin digestionProteinByr1PurificationGenesLesser extentPhorbol ester stimulates a protein-tyrosine/threonine kinase that phosphorylates and activates the Erk-1 gene product.
Alessandrini A, Crews CM, Erikson RL. Phorbol ester stimulates a protein-tyrosine/threonine kinase that phosphorylates and activates the Erk-1 gene product. Proceedings Of The National Academy Of Sciences Of The United States Of America 1992, 89: 8200-8204. PMID: 1518847, PMCID: PMC49885, DOI: 10.1073/pnas.89.17.8200.Peer-Reviewed Original ResearchMeSH KeywordsAnimalsBase SequenceCells, CulturedIn Vitro TechniquesMiceMitogen-Activated Protein Kinase 3Mitogen-Activated Protein KinasesMolecular Sequence DataMutagenesis, Site-DirectedOligodeoxyribonucleotidesPeptide MappingPhorbol EstersPhosphorylationPhosphothreonineProtein KinasesProtein-Tyrosine KinasesT-LymphocytesConceptsProtein kinase activityProtein kinaseGene productsKinase activityMyelin basic protein kinaseMyelin basic protein kinase activityMultiple extracellular signalsUpstream protein kinaseWild-type proteinIdentification of proteinsAmino acid residuesSame amino acid residuesERK-1 proteinDegree of phosphorylationReversible phosphorylationThreonine sitesThreonine kinaseExtracellular signalsTyrosine sitesAcid residuesKinasePhosphorylationPhorbol esterProteinThreonine