Video Killed the Biochemistry Star

First rule of science: collecting microscopy data is much more entertaining than turning it into publication—quality files. So we often…don’t. We hope that our cell phone videos are just as illuminating? See the embedded videos or visit our highly influenced and socially tiktaked Youtubing account:
https://www.youtube.com/channel/UCfIO5cab4BzeNBvs-2knIZQ/videos

Page 1 (Below, Cytoplasmic RNA granules)
Page 2 (Linked, Nuclear RNA bodies)
Page 3 (Linked, Multinucleated syncytia)
Page 4 (Linked, Miscellaneous Videos)

Stress granules (GFP-G3BP1, green) nucleate on the surface of pre-formed P-bodies (iRFP-LSM14A, magenta) in human U2OS cells (G3BP1/2 knockout). Video: 1-hour arsenite treatment.

Human U2OS G3BP1/2 knockout cells co-expressing stress granule-nucleating factor, G3BP (green), and P-body-nucleating protein, LSM14A (red), post-stress (arsenite treatment). The strong adhesion between the two condensates is readily observable (1-hour video), which is likely due to overlap between the RNP-interaction networks critical to formation of both condensates.

G3BP1/2 knockout U2OS cells with reconstituted optogenetic stress granules. 1-hour time lapse post-stress (arsenite); optogenetic activatation-deactivation cycling using Corelet technology. Green = ferritin Core oligomerization platform, red = G3BP DelNTF2 bait.

Human U2OS G3BP1/2 knockout cells expressing G3BP1 DelNTF2 Corelets (green, ferritin Core oligomerization platform; red, DelNTF2 optogenetic bait) with stress granule (SG) RNA-binding protein marker, HNRNPA1 (purple). Here, cells were pre-treated with arsenite for one-hour, which blocks translation and releases RNA into the cytoplasm, and subjected to iterative activation-deactivation cycles. The optogenetic SGs get larger with each cycle, as RNA floods into the cell and increases the network's connectivity.

G3BP1/2 knockout U2OS cells with reconstituted optogenetic stress granules (post-stress, arsenite); optogenetic activation-deactivation cycling, using Corelet technology. Green = ferritin Core oligomerization platform, red = G3BP DelNTF2 bait. Opto-SGs fuse and relax to sphere in liquid-like manner.

This is a fun experiment that we haven't followed up on extensively. Shown are G3BP1/2 knockout U2OS cells expressing G3BP1 DelNTF2 Corelets (Core oligomerization recruitment platform, green; optogenetic DelNTF2 bait, red) exposed to stress/arsenite + continuous blue-light activation for 1-hour. At end, we reverted the oligomerized RNA-binding domain to its monomeric form. The result? Explosion of individual stress granules into a swirling cacophony of mRNPs.

Human U2OS G3BP1/2 knockout cells expressing G3BP1 DelNTF2 Corelets (green, ferritin Core oligomerization platform; red, DelNTF2 optogenetic bait) with stress granule (SG)-nucleating factor, UBAP2L (purple). Here, cells were pre-treated with arsenite for one-hour, which blocks translation and releases RNA into the cytoplasm. UBAP2L nucleates small SG-like assemblies in the absence of G3BP1 DelNTF2 oligomerization. However, these assemblies are a bit different than canonical SGs with regard to protein/RNA components (in fact, a hybrid between stress granules and the related P-bodies). No worries, we arrive with blue-light triggered G3BP DelNTF2 optogenetic stress granules, in hand, and pull the pieces together. But upon disintegration of the glue? Chaos.