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PhosphoSens JAK2 (JH1) Protein Kinase Assays, Substrates & Recombinant Enzymes
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About JAK2 (JH1)
JAK2 (Janus Kinase 2) is a non-receptor tyrosine kinase belonging to the JAK family, which includes JAK1, JAK2, JAK3, and TYK2. JAK2 is constitutively associated with cytokine receptors lacking intrinsic kinase activity, including receptors for erythropoietin, thrombopoietin, growth hormone, and various interleukins. Upon cytokine binding, receptor dimerization triggers JAK2 transphosphorylation at Y1007/Y1008 within the activation loop, unleashing catalytic activity. Activated JAK2 phosphorylates receptor tyrosines that recruit STAT proteins (particularly STAT3 and STAT5), which dimerize, translocate to the nucleus, and drive transcription of genes governing proliferation, survival, and differentiation. The gain-of-function V617F mutation in the pseudokinase JH2 domain constitutively activates JAK2 and is found in over 95% of polycythemia vera cases and approximately 50% of essential thrombocythemia and myelofibrosis cases. This mutation makes JAK2 one of the most validated oncology targets in myeloproliferative neoplasms, and its role in cytokine signaling also implicates it in inflammatory diseases.
Why PhosphoSens for JAK2 (JH1)?
JAK2 drug discovery faces several assay challenges: the V617F mutant requires functional discrimination from wild-type, physiological ATP concentrations (~1 mM) are critical for selectivity profiling against competitive inhibitors, and endpoint assays like ADP-Glo or HTRF risk false positives from compound fluorescence interference and miss mechanistic nuance. Radiometric assays offer sensitivity but lack real-time kinetic information and pose disposal concerns. AssayQuant's PhosphoSens CSox-based peptide substrates enable continuous, real-time fluorescence monitoring of JAK2 phosphorylation without antibodies, supporting true Michaelis-Menten kinetics, accurate Ki determinations, and covalent inhibitor kinact/KI profiling. Full progress curves detect time-dependent inhibition and compound aggregation artifacts invisible to single-timepoint readouts. Running assays at physiological ATP concentrations provides translationally relevant potency data, directly improving the predictability of cellular and in vivo outcomes for JAK2 inhibitor programs.
Key Pathways:
JAK-STAT Signaling
Cytokine Receptor Signaling
Erythropoietin Receptor Signaling
Hematopoietic Growth Factor Signaling
Approved Inhibitors:
Ruxolitinib (Jakafi, Myelofibrosis/Polycythemia Vera/Acute GVHD
Fedratinib (Inrebic, Myelofibrosis
Pacritinib (Vonjo, Myelofibrosis
Momelotinib (Ojjaara, Myelofibrosis)
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How pricing works:
Select a kit or substrate below, then request a quote. Bundle discounts apply automatically.
Select a kit or substrate below, then request a quote. Bundle discounts apply automatically.
Real-Time JAK2 (JH1) Activity Assays
Continuous, real-time fluorescent assays optimized for quantitative JAK2 (JH1) activity measurements, IC50 determination, and mechanistic studies.
Assay Format: Continuous kinetic fluorescence (real-time)
PhosphoSens-Kinetic assays directly quantify enzyme activity by continuously monitoring substrate phosphorylation or dephosphorylation in real time, generating a full progress curve in every well.
Learn more about PhosphoSens-Kinetic →Need pricing or availability? Select a kit or substrate to request a quote below.
Kits
PhosphoSens-Kinetic Kinase Activity Kit - AQT0661
Ready-to-use assay kits containing substrate and all essential reagents.
Kit Contents
- Optimized PhosphoSens® substrate (AQT0661)
- ATP, DTT, EGTA, Reaction Buffer & Dilution Buffer
Automatically save 10% when bundling 10ug recombinant enzyme with your 1,000 assay kit. View enzymes
Price: $425
Substrate
PhosphoSens Kinase Substrate AQT0661
Bulk PhosphoSens® substrate for assay development and high-throughput workflows.
Specifications
Automatically save 10% when bundling Reagent Packs with your substrate. View Reagent Packs
Price: $2795
Ready to request pricing for JAK2 (JH1)?
Select a kit, substrate, or enzyme above. Our team will confirm pricing, availability, and any applicable bundle discounts.
Request a QuoteTRF JAK2 (JH1) Screening Assays
Robust endpoint TRF assays optimized for high-throughput screening and quantitative JAK2 (JH1) activity measurement in plate-based workflows.
Assay Format: Time-resolved fluorescence (TRF, endpoint)
PhosphoSens-Red assays use europium-based time-resolved fluorescence detection to enable robust, plate-based quantification of enzyme activity, making them well suited for high-throughput screening workflows.
Learn more about PhosphoSens-Red →Need pricing or availability? Select a kit or substrate to request a quote below.
Kits
PhosphoSens-Red Kinase Activity Kit - AQT0653
Ready-to-use TRF assay kits containing substrate and essential reagents.
Kit Contents
- Optimized PhosphoSens® substrate (AQT0653)
- ATP, DTT, EGTA, Reaction Buffer & Dilution Buffer
- Europium Detection Solution
Automatically save 10% when bundling 10ug recombinant enzyme with your 1,000 assay kit. View enzymes
Price: $455
Substrate
PhosphoSens Kinase Substrate AQT0653
Bulk substrate for PhosphoSens-Red TRF assays and high-throughput workflows.
Specifications
Automatically save 10% when bundling Reagent Packs with your substrate. View Reagent Packs
Price: $2795
Ready to request pricing for JAK2 (JH1)?
Select a kit, substrate, or enzyme above. Our team will confirm pricing, availability, and any applicable bundle discounts.
Request a QuoteNo recombinant enzymes are currently available for JAK2 (JH1).
Frequently Asked Questions: JAK2 (JH1) Assays
Can the PhosphoSens assay distinguish JAK2 wild-type from the V617F mutant?
Yes. Because PhosphoSens assays generate continuous progress curves, differences in catalytic rate (kcat/Km) between wild-type and V617F JAK2 can be quantified directly. The real-time format also enables inhibitor selectivity profiling against both forms simultaneously, providing critical mechanistic data for mutant-selective drug discovery campaigns.
What ATP concentration is used in the JAK2 PhosphoSens assay, and why does it matter?
AssayQuant's JAK2 assays can be run at physiological ATP concentrations (~1 mM), which is essential for accurately ranking ATP-competitive inhibitors as they would behave in a cellular context. Assays run at artificially low ATP concentrations systematically overestimate potency, leading to poor translation between biochemical IC50 values and cellular activity.
How does the PhosphoSens assay handle time-dependent or covalent JAK2 inhibitors?
The continuous, real-time readout of PhosphoSens is uniquely suited to detect time-dependent inhibition, which manifests as a characteristic nonlinear progress curve shape invisible to endpoint methods like ADP-Glo or HTRF. For covalent inhibitors, the assay directly measures kinact and KI from progress curve fitting, enabling full mechanistic characterization without additional secondary assays.
Data & Resources
Explore data and documents to support your kinase and phosphatase experiments. Download sample data, protocols and other resources to see how our assays perform and to help you get started in your own lab. All validation data generated using PhosphoSens® assays under recommended conditions.
Sample Report: AQT0734 - EGFR Assay Validation Report
Each validation report provides experimental conditions and data showing:
- Enzyme titration and linearity
- Sensor peptide substrate titration and Km determination
- ATP titration and Km determination
- DMSO titration and assay tolerance
- Inhibitor titration and IC50 determination
Protocol
Inhibitor IC50 Protocol
See how the PhosphoSens-Kinetic Assay can be used to find the IC50 of a kinase inhibitor.
Download Protocol →Webinar
Webinar: Continuous Assay Validation
Discover how continuous assay formats power deep understanding of kinase function. See how PhosphoSens® assays guide inhibitor profiling, selectivity assessment, and mechanistic characterization.
Watch the Webinar →Service
KinSight™ JAK2 (JH1) Profiling
Need broader selectivity data? KinSight profiling runs your compounds across our full kinase panel under identical PhosphoSens conditions.
Learn about KinSight →Stay Informed
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