2017
Glutathione-Responsive Selenosulfide Prodrugs as a Platform Strategy for Potent and Selective Mechanism-Based Inhibition of Protein Tyrosine Phosphatases
Tjin CC, Otley KD, Baguley TD, Kurup P, Xu J, Nairn AC, Lombroso PJ, Ellman JA. Glutathione-Responsive Selenosulfide Prodrugs as a Platform Strategy for Potent and Selective Mechanism-Based Inhibition of Protein Tyrosine Phosphatases. ACS Central Science 2017, 3: 1322-1328. PMID: 29296673, PMCID: PMC5746864, DOI: 10.1021/acscentsci.7b00486.Peer-Reviewed Original ResearchStriatal-enriched protein tyrosine phosphataseProtein tyrosineTyrosine phosphatasePhosphatase inhibitorProtein tyrosine phosphataseProtein tyrosine phosphorylation levelsActive site cysteineProtein tyrosine phosphorylationTyrosine phosphorylation levelsHuman PTPsSite cysteinePTP targetsTyrosine phosphorylationRepresentative cysteine proteaseCysteine proteasesHuman diseasesCellular activitiesPhosphorylation levelsVirulence factorsEssential roleSelective mechanismIntracellular GSH concentrationSelective active sitesNeurodegenerative diseasesPTP
2016
STEP activation by Gαq coupled GPCRs opposes Src regulation of NMDA receptors containing the GluN2A subunit
Tian M, Xu J, Lei G, Lombroso PJ, Jackson MF, MacDonald JF. STEP activation by Gαq coupled GPCRs opposes Src regulation of NMDA receptors containing the GluN2A subunit. Scientific Reports 2016, 6: 36684. PMID: 27857196, PMCID: PMC5114553, DOI: 10.1038/srep36684.Peer-Reviewed Original ResearchConceptsStriatal-enriched protein tyrosine phosphataseFamily of kinasesProtein tyrosine phosphataseM1R stimulationN-methyl-D-aspartate receptorsM1 muscarinic acetylcholine receptorSrc recruitmentTyrosine phosphataseSrc regulationNMDAR functionIntracellular Ca2Step activationMuscarinic acetylcholine receptorsGluN2A subunitGαqAcetylcholine receptorsHigh intracellular Ca2Function of NMDARsSynaptic plasticityPhosphataseNMDAR activationActivationReceptorsRecruitmentCa2
2015
Down‐regulation of BDNF in cell and animal models increases striatal‐enriched protein tyrosine phosphatase 61 (STEP61) levels
Xu J, Kurup P, Azkona G, Baguley TD, Saavedra A, Nairn AC, Ellman JA, Pérez-Navarro E, Lombroso PJ. Down‐regulation of BDNF in cell and animal models increases striatal‐enriched protein tyrosine phosphatase 61 (STEP61) levels. Journal Of Neurochemistry 2015, 136: 285-294. PMID: 26316048, PMCID: PMC4769989, DOI: 10.1111/jnc.13295.Peer-Reviewed Original ResearchMeSH KeywordsAnimalsBenzothiepinsBrainBrain-Derived Neurotrophic FactorCells, CulturedCysteine Proteinase InhibitorsDown-RegulationEmbryo, MammalianFemaleFlavonesLeupeptinsMaleMiceMice, Inbred C57BLMice, TransgenicMotor ActivityNeuronsProtein Tyrosine PhosphatasesRatsRats, Sprague-DawleyRNA, Small InterferingTime FactorsConceptsBrain-derived neurotrophic factorNormal cognitive functionSynaptic strengtheningStriatal-enriched protein tyrosine phosphataseBDNF expressionBDNF knockdownCortical culturesRegulation of BDNFN-methyl-D-aspartate receptor functionNeuropsychiatric disordersCognitive functionBetter therapeutic strategiesMouse frontal cortexNMDA receptor subunit GluN2BSTEP61 levelsHyperlocomotor activityMotor abnormalitiesNeurotrophic factorNMDA receptorsFrontal cortexKinase B signalingTherapeutic strategiesAgonists resultsAnimal modelsCultured neuronsBDNF Induces Striatal-Enriched Protein Tyrosine Phosphatase 61 Degradation Through the Proteasome
Saavedra A, Puigdellívol M, Tyebji S, Kurup P, Xu J, Ginés S, Alberch J, Lombroso PJ, Pérez-Navarro E. BDNF Induces Striatal-Enriched Protein Tyrosine Phosphatase 61 Degradation Through the Proteasome. Molecular Neurobiology 2015, 53: 4261-4273. PMID: 26223799, PMCID: PMC4738169, DOI: 10.1007/s12035-015-9335-7.Peer-Reviewed Original ResearchMeSH KeywordsAnimalsBrain-Derived Neurotrophic FactorCerebral CortexExtracellular Signal-Regulated MAP KinasesHippocampusMembrane PotentialsMiceNeostriatumNerve Growth FactorNeuronsNeurotrophin 3Phospholipase C gammaPhosphorylationProteasome Endopeptidase ComplexProtein Tyrosine Phosphatases, Non-ReceptorProteolysisReceptors, N-Methyl-D-AspartateUbiquitinationConceptsBrain-derived neurotrophic factorSTEP61 levelsCortical neuronsUbiquitin-proteasome systemStriatal-enriched protein tyrosine phosphatasePrimary cortical neuronsLevels/activitiesNerve growth factorNeurotrophic factorNeurotrophin-3Cultured striatalHippocampal neuronsCell depolarizationGrowth factorERK1/2 phosphorylationNeuronsStriatalTyrosine kinasePhospholipase C-gammaC gammaDifferent mechanismsLevelsBlockadeGluN2BProtein tyrosine phosphataseStriatal‐enriched protein tyrosine phosphatase regulates the PTPα/Fyn signaling pathway
Xu J, Kurup P, Foscue E, Lombroso PJ. Striatal‐enriched protein tyrosine phosphatase regulates the PTPα/Fyn signaling pathway. Journal Of Neurochemistry 2015, 134: 629-641. PMID: 25951993, PMCID: PMC4516628, DOI: 10.1111/jnc.13160.Peer-Reviewed Original ResearchConceptsProtein tyrosine phosphataseProtein kinase ARegulation of FynTyrosine phosphataseReceptor-type protein tyrosine phosphatase alphaProtein tyrosine phosphatase alphaStriatal-enriched protein tyrosine phosphataseRegulatory tyrosine residuesActivation of FynTyrosine kinase FynRegulatory tyrosineProtein tyrosinePTPαKinase FynSynaptic membranesKinase ATyrosine residuesFyn activityFynNovel substratePrimary neuronal culturesSTEP61Synergistic regulationMolecular techniquesNovel mechanism
2013
Striatal-Enriched Protein Tyrosine Phosphatase—STEPs Toward Understanding Chronic Stress-Induced Activation of Corticotrophin Releasing Factor Neurons in the Rat Bed Nucleus of the Stria Terminalis
Dabrowska J, Hazra R, Guo JD, Li C, DeWitt S, Xu J, Lombroso PJ, Rainnie DG. Striatal-Enriched Protein Tyrosine Phosphatase—STEPs Toward Understanding Chronic Stress-Induced Activation of Corticotrophin Releasing Factor Neurons in the Rat Bed Nucleus of the Stria Terminalis. Biological Psychiatry 2013, 74: 817-826. PMID: 24012328, PMCID: PMC3818357, DOI: 10.1016/j.biopsych.2013.07.032.Peer-Reviewed Original ResearchConceptsStriatal-enriched protein tyrosine phosphataseLong-term potentiationProtein tyrosine phosphataseCRF neuronsReverse transcriptase-polymerase chain reactionTranscriptase-polymerase chain reactionRestraint stressTyrosine phosphatasePolymerase chain reactionBed nucleusFactor neuronsStria terminalisWhole-cell patch-clamp electrophysiologyInduction of LTPRole of STEPQuantitative reverse transcriptase-polymerase chain reactionChain reactionNovel treatment strategiesStress-induced anxiety disordersAnxiety-like behaviorSingle-cell reverse transcriptase-polymerase chain reactionPatch-clamp electrophysiologyStress-Induced ActivationRat bed nucleusTyrosine phosphatase STEP
2012
Striatal-enriched Protein-tyrosine Phosphatase (STEP) Regulates Pyk2 Kinase Activity*
Xu J, Kurup P, Bartos JA, Patriarchi T, Hell JW, Lombroso PJ. Striatal-enriched Protein-tyrosine Phosphatase (STEP) Regulates Pyk2 Kinase Activity*. Journal Of Biological Chemistry 2012, 287: 20942-20956. PMID: 22544749, PMCID: PMC3375518, DOI: 10.1074/jbc.m112.368654.Peer-Reviewed Original ResearchConceptsStriatal-enriched protein tyrosine phosphataseProtein tyrosine phosphataseN-Methyl-d-aspartate (NMDA) Receptor TraffickingFocal adhesion kinase familyPyk2 activationProline-rich tyrosine kinase 2Pyk2 kinase activityTyrosine kinase 2Kinase familyKinase membersCytoskeletal reorganizationDiverse functionsKinase activitySTEP KO miceReceptor traffickingKinase 2Tyrosine sitesPyk2 activityEnhanced phosphorylationCell adhesionPyk2PhosphorylationFunctional studiesHematopoietic cellsPostsynaptic densityStriatal-Enriched Protein Tyrosine Phosphatase in Alzheimer’s Disease
Xu J, Kurup P, Nairn AC, Lombroso PJ. Striatal-Enriched Protein Tyrosine Phosphatase in Alzheimer’s Disease. Advances In Pharmacology 2012, 64: 303-325. PMID: 22840751, PMCID: PMC3740556, DOI: 10.1016/b978-0-12-394816-8.00009-x.Peer-Reviewed Original ResearchConceptsAlzheimer's diseaseNeurofibrillary tanglesStriatal-enriched protein tyrosine phosphataseAmyloid plaquesTreatment of ADHyperphosphorylated tau proteinSubstantial economic burdenProgressive diseasePotential clinical applicationsClinical symptomsBeta amyloidGlutamate receptorsEconomic burdenTau proteinCortical accumulationCognitive functionMemory lossBeneficial effectsDiseaseNeuronal membranesCommon formMultiple intracellularMillions of peopleClinical applicationImportant target
2011
Reduced levels of the tyrosine phosphatase STEP block beta amyloid‐mediated GluA1/GluA2 receptor internalization
Zhang Y, Kurup P, Xu J, Anderson GM, Greengard P, Nairn AC, Lombroso PJ. Reduced levels of the tyrosine phosphatase STEP block beta amyloid‐mediated GluA1/GluA2 receptor internalization. Journal Of Neurochemistry 2011, 119: 664-672. PMID: 21883219, PMCID: PMC3192910, DOI: 10.1111/j.1471-4159.2011.07450.x.Peer-Reviewed Original ResearchConceptsAD mouse modelMouse modelTriple transgenic AD mouse modelAlzheimer's diseaseTransgenic AD mouse modelGluA2 receptorsAD prefrontal cortexElevated levelsGluA1/GluA2Cortical culturesBeta amyloidRegulate surface expressionCognitive deficitsStriatal-enriched protein tyrosine phosphatasePrefrontal cortexΑ-aminoReceptorsReceptor internalizationSurface expressionReduced levelsReceptor complexCortexDiseaseMiceAβStriatal-Enriched Protein Tyrosine Phosphatase Expression and Activity in Huntington's Disease: A STEP in the Resistance to Excitotoxicity
Saavedra A, Giralt A, Rué L, Xifró X, Xu J, Ortega Z, Lucas JJ, Lombroso PJ, Alberch J, Pérez-Navarro E. Striatal-Enriched Protein Tyrosine Phosphatase Expression and Activity in Huntington's Disease: A STEP in the Resistance to Excitotoxicity. Journal Of Neuroscience 2011, 31: 8150-8162. PMID: 21632937, PMCID: PMC3472648, DOI: 10.1523/jneurosci.3446-10.2011.Peer-Reviewed Original ResearchMeSH KeywordsAnimalsBrainCalcineurinCell DeathDisease Models, AnimalGene Expression RegulationGene Products, tatHuntingtin ProteinHuntington DiseaseMiceMice, Neurologic MutantsMice, TransgenicMicroinjectionsNerve Tissue ProteinsNuclear ProteinsPhosphorylationProtein Tyrosine Phosphatases, Non-ReceptorQuinolinic AcidSignal TransductionConceptsStriatal-enriched protein tyrosine phosphataseCell deathSTEP expressionPhosphorylation levelsProtein Tyrosine Phosphatase ExpressionProtein tyrosine phosphataseSTEP phosphorylationTyrosine phosphataseProtein kinasePhosphorylated ERK2Phosphatase expressionHuntington's diseaseSTEP proteinMutant huntingtinCalcineurin activityPhosphorylationExon 1STEP protein levelsDisease mouse modelProtein levelsMouse modelMouse striatumTAT-STEPHuntington's disease mouse modelExpression
2009
Extrasynaptic NMDA Receptors Couple Preferentially to Excitotoxicity via Calpain-Mediated Cleavage of STEP
Xu J, Kurup P, Zhang Y, Goebel-Goody SM, Wu PH, Hawasli AH, Baum ML, Bibb JA, Lombroso PJ. Extrasynaptic NMDA Receptors Couple Preferentially to Excitotoxicity via Calpain-Mediated Cleavage of STEP. Journal Of Neuroscience 2009, 29: 9330-9343. PMID: 19625523, PMCID: PMC2737362, DOI: 10.1523/jneurosci.2212-09.2009.Peer-Reviewed Original ResearchMeSH KeywordsAlternative SplicingAnimalsBrainCalpainCell DeathCells, CulturedCyclin-Dependent Kinase 5EndocytosisGlutamic AcidIn Vitro TechniquesMiceMice, KnockoutMitogen-Activated Protein Kinase 1Mitogen-Activated Protein Kinase 3NeuronsP38 Mitogen-Activated Protein KinasesProtein Tyrosine Phosphatases, Non-ReceptorRatsRats, Sprague-DawleyReceptors, N-Methyl-D-AspartateSynapsesConceptsStriatal-enriched protein tyrosine phosphataseCalpain cleavage sitesP38 activationCell deathCleavage siteExtracellular signal-regulated kinase 1/2Protein tyrosine phosphataseSignal-regulated kinase 1/2Promotes cell survivalActivation of p38Tyrosine phosphataseSubstrate bindingKinase 1/2ERK1/2 activationCalpain cleavageCell survivalNovel mechanismCalpain-mediated proteolysisReceptors coupleP38NMDAR stimulationPostsynaptic terminalsValid targetCleavage productsSTEP substrates