Cryo-electron tomography of NLRP3-activated ASC complexes reveals organelle co-localization.
Yangci LiuHaoming ZhaiHelen AlemayehuJérôme BoulangerLee J HopkinsAlicia C BorgeaudChristina HerovenJonathan D HoweKendra E LeighClare E BryantYorgo ModisPublished in: Nature communications (2023)
NLRP3 induces caspase-1-dependent pyroptotic cell death to drive inflammation. Aberrant activity of NLRP3 occurs in many human diseases. NLRP3 activation induces ASC polymerization into a single, micron-scale perinuclear punctum. Higher resolution imaging of this signaling platform is needed to understand how it induces pyroptosis. Here, we apply correlative cryo-light microscopy and cryo-electron tomography to visualize ASC/caspase-1 in NLRP3-activated cells. The puncta are composed of branched ASC filaments, with a tubular core formed by the pyrin domain. Ribosomes and Golgi-like or endosomal vesicles permeate the filament network, consistent with roles for these organelles in NLRP3 activation. Mitochondria are not associated with ASC but have outer-membrane discontinuities the same size as gasdermin D pores, consistent with our data showing gasdermin D associates with mitochondria and contributes to mitochondrial depolarization.
Keyphrases
- nlrp inflammasome
- cell death
- electron microscopy
- high resolution
- cell cycle arrest
- induced apoptosis
- oxidative stress
- high throughput
- single molecule
- endothelial cells
- endoplasmic reticulum
- endoplasmic reticulum stress
- machine learning
- electronic health record
- high speed
- reactive oxygen species
- big data
- deep learning
- single cell
- photodynamic therapy
- network analysis