A cell is like a big house, and it has its own janitor. His job is to make sure toxic trash doesn't pile up indoors. In progeria, a disease that makes children age five times faster than normal, a toxic protein called progerin accumulates in the cell nucleus. It latches onto the inner lining of the nucleus like tar stuck to a wall, and little by little it warps the whole room.
It then turned out that progerin is destroyed not through the proteasome (a protein shredder) but through ubiquitin-dependent autophagy (a waste-recycling system). The janitor doesn't just sweep; he sorts the trash and sends it for recycling rather than into the general incinerator. After treatment, the share of cells with deformed nuclei fell from 87.5% to 62.5%. The cells looked healthier, and their division slowed down, just as you'd expect from cells that are no longer scrambling to survive under a toxic load.
This discovery changes how we think about treating progeria. Instead of editing genes or blocking enzymes with severe side effects, you can simply boost the work of the cell's janitor. He will find the toxic protein himself, tag it, and send it off for recycling.
Progerin arises from a mutation that activates a hidden splice site in the LMNA gene. As a result, the protein loses 50 amino acids, including the cleavage site for the enzyme ZMPSTE24, and remains permanently attached to the nuclear membrane.
Not published on arXiv. Here are its page, the PDF and the formalization: you can check it yourself, not only read our account.