| Category | Key points | Recent evidence (2023-2024) | Notes |
|---|---|---|---|
| definition/concept | • Arabidopsis **NPR1 = AtNPR1 / NIM1 / SAI1**, matching UniProt **P93002** • Central **salicylic acid (SA) signaling co-regulator/receptor** required for **PR gene induction** and **systemic acquired resistance (SAR)** • Functions as a **nucleo-cytoplasmic master regulator** of defense transcription (pqac-00000005, pqac-00000023, pqac-00000024, pqac-00000026) | Goyal 2024 dissertation excerpt; Kim & Lim 2023; Saur 2024 bioRxiv (pqac-00000005, pqac-00000019, pqac-00000026) | Recent reviews/dissertation excerpts consistently support the classic Arabidopsis NPR1 identity; some mechanistic points remain model-dependent across studies. |
| domains | • Contains **BTB/POZ domain** plus **four ankyrin repeats** consistent with protein-protein interaction roles • Includes **nuclear localization signal** and **LENRV-like SA-binding motif** • NIb interaction mapped to the **central ankyrin domain** and depends on **SIM3** region for viral interference (pqac-00000000, pqac-00000005, pqac-00000012, pqac-00000026) | Liu et al. 2023 Nature Communications; Goyal 2024 dissertation excerpt; Saur 2024 bioRxiv (pqac-00000000, pqac-00000012, pqac-00000026) | Structural details are partly summarized indirectly from excerpts; Zhang 2025 notes 2022 structural work but the primary structure paper was not directly excerpted here (pqac-00000002). |
| localization | • In uninduced cells, NPR1 is largely in **cytosolic oligomeric complexes** • SA-associated redox change promotes **monomerization** and **nuclear translocation** • In guard cells/systemic leaves, NPR1 is important for **stomatal immunity** and distal defense responses (pqac-00000000, pqac-00000003, pqac-00000015, pqac-00000025) | Guan et al. 2023 Plants; Goyal 2024 dissertation excerpt (pqac-00000015, pqac-00000023, pqac-00000025) | Nuclear localization is necessary but not sufficient; excerpts note an additional **SA-dependent conformational activation** step (pqac-00000000, pqac-00000023). |
| regulation PTMs | • **Redox control:** disulfide-linked oligomers involve **Cys82/Cys216**; **S-nitrosylation at Cys156** favors oligomer accumulation • **Phosphorylation:** **Ser11/Ser15** phosphodegron promotes transcriptional activity/turnover • **SUMOylation/ubiquitination:** SUMO3-linked activation interfaces with CRL3/CUL3-, UBE4-, and UBP6/7-mediated turnover (pqac-00000000, pqac-00000008, pqac-00000009, pqac-00000010, pqac-00000011, pqac-00000023) | Liu et al. 2023 Nature Communications; Goyal 2024 dissertation excerpt (pqac-00000008, pqac-00000010, pqac-00000011, pqac-00000023) | Strongest 2023 primary evidence here concerns viral suppression of NPR1 SUMOylation/phosphorylation; some broader PTM framework is synthesized in the dissertation excerpt rather than directly from each primary paper. |
| key partners | • Interacts with **TGA transcription factors** to activate SA-responsive promoters such as **PR1** • **NPR3/NPR4** act as SA receptors/CRL3 substrate adaptors modulating NPR1 stability • **NIMIN proteins** bind NPR1 and can repress or tune SA responses; **NIb** from potyvirus targets NPR1 to suppress immunity (pqac-00000004, pqac-00000006, pqac-00000019, pqac-00000021, pqac-00000022, pqac-00000008) | Kim & Lim 2023; Liu et al. 2023; Saur 2024 bioRxiv (pqac-00000004, pqac-00000006, pqac-00000019, pqac-00000021, pqac-00000008) | NIMIN-related mechanisms in 2024 are from bioRxiv and should be treated as provisional until peer reviewed. |
| phenotypes/quantitative data | • In **npr1** mutants, viral accumulation increased **~1.8- to 2.1-fold** versus WT in the TuMV pathosystem • TuMV infection induced **PR1 >5-fold** in WT, consistent with NPR1 pathway activation • In systemic stomatal immunity, proteomics found **335 WT-mock-only**, **204 WT-primed-only**, **337 npr1-1 mock**, and **526 npr1-1 primed** DAPs; some ribosomal protein changes reached **log2FC ~6**, catalase 2 **~3.94 log2FC** (pqac-00000013, pqac-00000017, pqac-00000018) | Liu et al. 2023 Nature Communications; Guan et al. 2023 Plants (pqac-00000013, pqac-00000017, pqac-00000018) | Useful recent quantitative evidence exists, but many aperture/ROS numeric values were not present in the available excerpts. |
| applications | • NPR1 is the canonical node leveraged by **SA-pathway plant activators** and **SAR engineering** • Commercial or field-relevant activators include **BTH/ASM (Bion)** and **INA**; several downstream activators fail in **npr1** backgrounds, supporting NPR1 dependence • Translational relevance extends across crops including wheat, rice, tomato, cucumber, maize, cotton, soybean (pqac-00000027, pqac-00000028, pqac-00000030, pqac-00000034) | Naz et al. 2024 Genes; Zhao et al. 2024 Frontiers review (pqac-00000027, pqac-00000028, pqac-00000030, pqac-00000034) | Application evidence is largely review-based and often crop-translational rather than direct Arabidopsis functional annotation; however it shows how NPR1 knowledge is implemented in agriculture. |


*Table: This table summarizes the verified identity, molecular function, localization, regulatory mechanisms, partners, quantitative phenotypes, and applications of Arabidopsis thaliana NPR1 (UniProt P93002). It uses only the provided context snippets, emphasizing recent 2023-2024 evidence.*