JAK-STAT signaling pathway
Cytokines and interferons assemble homo/hetero-receptor complexes that recruit JAK1/2/3 and TYK2, driving trans-autophosphorylation of receptors and JAKs. STAT proteins are then phosphorylated, dimerize, and translocate to the nucleus to orchestrate antiviral, inflammatory, hematopoietic, and proliferative programs. SOCS proteins, phosphatases, and E3 ligases shape signal amplitude and duration.
1. Key targets
JAKs & receptor coupling
- JAK1 / JAK2 / JAK3 / TYK2
Cytokine receptors prefer specific JAK pairs; clinical JAKi selectivity and infection risk track isoform usage.
- STAT1–STAT6
STAT1/2 dominate type I IFN programs; STAT3/5 are common for IL-6 family and γc cytokines; STAT4 links IL-12/23.
- SOCS / PIAS / PTP
SOCS proteins block STAT recruitment and promote turnover; SHP2-like PTPs tune thresholds at receptors.
Representative receptor modules
- IFNAR / IFNGR；IL6R–IL6ST（gp130）；IL2Rβ/γc；IL12Rβ1/β2
- GHR, PRLR, EpoR also couple via JAK2
Crosstalk
- MAPK, PI3K/Akt, mTORC1 often co-regulate STAT3 survival/metabolic genes
- NF-κB can cooperate or compete with STAT at inflammatory promoters
Supplement: JAK-STAT targets (gene symbols)
Below the overview, HGNC symbols group JAK kinases, STAT factors, negative feedback, and cytokine receptors—validate isoforms and stimulation context with databases and literature.
STAT & downstream
2. Suggested experimental readouts
Phospho-STAT sites vary by ligand and clone—pair with total STAT, fractionation or IF, and include cytokine stimulation plus JAK inhibitor controls.
- p-STAT3 (Tyr705), p-STAT1 (Tyr701), p-STAT5 (Tyr694/699—isoform-dependent)
- Total STAT and nuclear accumulation (fractionation or phospho-IF)
- SOCS3, IRF9, MX1, OAS1 transcriptional readouts (IFN vs IL-6 context)
- p-JAK2 (Tyr1007/1008) with receptor co-IP (project-dependent)
3. Cytokine context: receptor–JAK–STAT bias
| Ligand family (examples) | Receptor / JAK bias | Dominant STAT readouts | Notes |
|---|---|---|---|
| Type I / II IFN | IFNAR / IFNGR；JAK1–TYK2 / JAK1–JAK2 | STAT1/2；ISGF3（STAT1/2 + IRF9） | Antiviral and MHC-I processing clusters; chronic STAT1 activation can be toxic. |
| IL-6 家族 | gp130 二聚化；JAK1–JAK2 | STAT3（acute-phase、肿瘤微环境常见） | Pair with acute-phase proteins; overlaps IL-11/LIF programs. |
| γc 家族（IL-2/7/15 等） | γc + 私有链；JAK1–JAK3 | STAT5A/B | Lymphocyte homeostasis; relevant to immunotherapy monitoring. |
4. Clinical & disease context
- MPN / JAK2 V617F: JAK2-activating mutations drive STAT5 programs in MPNs—annotate molecular pathology.
- Inflammation & autoimmunity: JAK inhibitors are used in RA, AD, IBD, etc.—monitor infections and lipids clinically.
- Tumor microenvironment: CAF/myeloid IL-6 family can sustain STAT3 pro-survival axes—hot topic for checkpoint response biology.
JAK-STAT–related antibodies (curated)
5. Product lines & on-site search
Primary & phospho antibodies
JAK1/2/3, TYK2, STAT1–6, p-STAT1/3/5, SOCS1/3, IRF9, gp130, IL6R, IFNAR1/2, IFNGR1/2—WB/IHC/IF/FC per datasheet.
Recombinant cytokines / neutralization
IFN-α/β, IL-6, IL-2 for stimulation; neutralizing antibodies / receptor-Fc fusions per availability and ethics.
Quick search (site)
6. Inhibitors & tool compounds (summary)
Clinical JAK inhibitors are prescription drugs; for in vitro research, control WT vs mutant backgrounds and dosing/washout.
JAK1/2; common control in MPN/GVHD models.
JAK1/3-biased; immune/inflammation models.
JAK1/2; COVID-19 / arthritis contexts.
More JAK2-selective; resistance/mutation controls.
Selective JAK1 inhibitor; AD/arthritis research contexts.
STAT3 dimerization/transcriptional interface tools (mind off-targets).
7. Pathway schematic
- Cytokine-induced receptor oligomerization
- JAK trans-phosphorylation and STAT recruitment
- STAT Tyr phosphorylation and dimerization
- Nuclear gene regulation & SOCS feedback
8. Pathway biology overview
JAK-STAT is a rapid cytokine-to-transcription axis—ISGs, acute-phase proteins, and cell-cycle regulators can shift within minutes to hours. Hyperactive or sustained signaling links to chronic inflammation, TME remodeling, and autoimmunity, making it a frequent target for small molecules and biologics.
- Hematopoiesis: Epo, Tpo, G-CSF receptors couple via JAK2
- Antiviral: IFN amplifies via STAT1/2 and IRF cascades
9. Related pathways on this site
10. External databases & modification resources
11. References
Mechanisms & feedback
- • Ihle JN. (2001). The Stat family in cytokine signaling. Curr Opin Cell Biol. 13(2):211-7.
- • Alexander WS, Hilton DJ. (2004). The role of suppressors of cytokine signaling (SOCS) proteins in regulation of the immune response. Annu Rev Immunol. 22:503-29.
Targeting & therapy
- • O'Shea JJ, et al. (2015). The JAK-STAT pathway: twenty years on. Nat Rev Immunol. 15(10):575-86.
- • Banerjee S, et al. (2017). JAK-STAT signaling as a target for inflammatory and autoimmune diseases: current and future prospects. Drugs. 77(5):521-46.