NEK7 protein (NIMA-related kinase 7) is a 34 kDa serine/threonine kinase encoded by the NEK7 gene. NEK7 is the essential structural mediator of NLRP3 inflammasome assembly, directly bridging NLRP3 protomers to enable oligomerization. In the brain, NEK7-dependent inflammasome activation in microglia is a major driver of neuroinflammatory damage in Alzheimer's disease and Parkinson's disease.
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| Protein Name | Serine/threonine-protein kinase NEK7 |
| Gene | [NEK7](/genes/nek7) |
| UniProt ID | [Q8TDX2](https://www.uniprot.org/uniprot/Q8TDX2) |
| PDB IDs | [6NPY](https://www.rcsb.org/structure/6NPY), [2WQM](https://www.rcsb.org/structure/2WQM) |
| Molecular Weight | 34.5 kDa |
| Subcellular Localization | Cytoplasm, centrosome |
| Protein Family | NEK (NIMA-related kinase) family |
| Associated Diseases | [Alzheimer's disease](/diseases/alzheimers-disease), [Parkinson's disease](/diseases/parkinsons-disease), [ALS](/diseases/amyotrophic-lateral-sclerosis) |
¶ Domain Architecture
NEK7 is a relatively compact kinase consisting of:
- N-terminal extension (residues 1-20): Unstructured region that contributes to protein-protein interactions
- Kinase domain (residues 21-302): Bilobal kinase fold with a canonical ATP-binding pocket; the C-lobe mediates the critical interaction with NLRP3
- Activation segment: Contains the conserved DFG motif and T-loop with Thr187 as the activating phosphorylation site
The cryo-EM structure of the NEK7-NLRP3 complex (PDB: 6NPY) reveals that NEK7 contacts both the leucine-rich repeat (LRR) domain and the nucleotide-binding domain (NBD/NACHT) of NLRP3. Key interface residues include:
- C-lobe of NEK7: Arg121, Glu122, Leu160, and Arg163 form hydrogen bonds with NLRP3 LRR
- Back of the kinase domain: Additional contacts with the NLRP3 NACHT domain enable bridging between adjacent NLRP3 protomers
- The binding interface buries approximately 2,000 Ų of surface area
NEK7 shares 87% kinase domain identity with NEK6, but NEK6 cannot substitute for NEK7 in NLRP3 activation. Critical differences in the N-terminal extension and C-lobe surface residues determine NLRP3 binding specificity.
During cell division, NEK7 is phosphorylated and activated by NEK9. The NEK9-NEK7 complex promotes:
- Centrosome separation through phosphorylation of EG5/KIF11
- Microtubule nucleation at spindle poles
- Cytokinetic abscission
In interphase cells, NEK7 is the obligate structural component for NLRP3 inflammasome formation:
- Danger signals (potassium efflux, mitochondrial ROS, lysosomal rupture) trigger NLRP3 conformational change
- NEK7 binds activated NLRP3 monomers in a 1:1 stoichiometry
- NEK7-NLRP3 heterodimers oligomerize into a disc-shaped platform
- The NLRP3 disc recruits ASC via PYD-PYD interactions
- ASC filaments recruit pro-caspase-1 for auto-activation
- Active caspase-1 cleaves pro-IL-1β and pro-IL-18 into mature cytokines
- Caspase-1 also cleaves gasdermin D, forming membrane pores for cytokine release
NEK7 cannot simultaneously serve both mitotic and inflammasome functions. During mitosis, NEK9 sequesters NEK7 at centrosomes, preventing inflammasome activation. This switch ensures that inflammatory responses do not interfere with cell division.
NEK7-NLRP3 signaling is a central hub in AD neuroinflammation:
- Amyloid-beta fibrils phagocytosed by microglia cause lysosomal disruption, activating NEK7-NLRP3
- The resulting IL-1β promotes tau hyperphosphorylation, creating a feed-forward loop between amyloid pathology and tauopathy
- Plaque-associated microglia in AD brains show elevated NEK7 and NLRP3 co-expression
- Conditional deletion of microglial Nek7 in APP/PS1 mice reduces plaque burden, tau phosphorylation, and synaptic loss
Multiple PD-relevant stimuli converge on NEK7-NLRP3:
- Extracellular α-synuclein aggregates trigger potassium efflux in microglia
- Mitochondrial complex I deficiency increases ROS, activating NEK7-NLRP3
- LRRK2 G2019S gain-of-function enhances NLRP3 priming through NF-κB
- PINK1/Parkin deficiency impairs mitophagy, increasing mitochondrial DAMPs that activate NEK7-NLRP3
SOD1 mutant microglia show enhanced NEK7-NLRP3 complex formation. TDP-43 cytoplasmic aggregates also activate NLRP3 through mitochondrial damage pathways.
¶ Traumatic Brain Injury and Stroke
Acute neurological injuries rapidly activate NEK7-NLRP3 in microglia and infiltrating macrophages, amplifying secondary injury through IL-1β-driven neuroinflammation.
- Protein-protein interaction (PPI) disruptors: Small molecules targeting the NEK7-NLRP3 interface could selectively block inflammasome assembly without affecting NEK7 mitotic functions
- Stapled peptides: Designed to mimic the NEK7 C-lobe surface and competitively inhibit NLRP3 binding
- Allosteric modulators: Compounds that shift NEK7 conformation to disfavor NLRP3 interaction
- MCC950 (CRID3) blocks NLRP3 ATPase activity downstream of NEK7 and has shown efficacy in AD and PD models
- Dapansutrile (OLT1177) is in clinical trials for inflammatory conditions
- CY-09 and Tranilast represent additional NLRP3-targeting scaffolds
- NEK7-targeting antisense oligonucleotides (ASOs) reduce inflammasome activation in rodent models of neurodegeneration
- CRISPR-mediated NEK7 disruption in iPSC-derived microglia validates the target for human disease