TEÄRS

Transcriptionally Engineered Addressable RNA Solvent droplets, in short TEARS, are condensates based on CUG repeat RNA, which form due to extensive intra-and interstrand basepairing.

By fusing the CUG RNA to RNA sequences that have known protein interaction modules (e.g., MS2 system), one can engineer client proteins that will be specifically recruited to TEARS. This system has currently been used to engineer metabolic pathways in bacteria.

PROS:
+ RNA based
+ easily tunable based on RNA length
+ compatible with commonly used RNA binding domains for functionalization

CONS:
- two-component system
- CUG RNA foci are toxic in animal/cell models
- CUG RNA may be subjected to degradation, processing, or RAN translation