A recent study challenges the idea that liquid-liquid phase separation leads to the formation of amyloid fibrils, a key feature of Parkinson’s disease. Instead, the study suggests that protein droplets may actually help to dissolve aggregated proteins, shedding light on neurodegenerative diseases tied to protein buildup and offering potential for new therapeutic avenues. The research was published in the journal Advanced Science.
Think of adding vinegar to oil and shaking it: you’ll see oil droplets form. This phenomenon of liquid-liquid phase separation is a concept deeply ingrained in everyday life and has emerged as a major focus in biological research.
About fifteen years ago, it was discovered that proteins could gather into droplets within cells without the need for a surrounding membrane. In early-stage roundworm embryos, proteins and RNA were seen forming tiny droplets that play a role in genetic material management.
This breakthrough altered our understanding of cell functions. Liquid-liquid phase separation, honed by evolution, appears to serve crucial purposes. These droplets enable cells to compartmentalize molecules and control biochemical reactions. As scientists grew more open to this concept, they began detecting these droplets in various cell locations – from the nucleus aiding DNA organization to stress granules safeguarding and regulating mRNA, and even as molecular adhesive at microtubule ends, facilitating proper nucleus positioning during cell division.
Besides their functional importance, droplets have also been linked to diseases. In cases of neurodegenerative diseases marked by protein clumps, like Alzheimer’s and Parkinson’s, there’s been speculation that protein droplets might trigger abnormal protein buildup.
The theory behind this assumption suggests that droplets could concentrate specific proteins, potentially encouraging their aggregation. Several observations have noted that conditions such as salt levels or pH can promote both protein aggregation and condensation simultaneously. However, the actual connection between the two phenomena has yet to be definitively proven.
