The protein Death Star
This is HtrA, or High Temperature Requirement A - a protein found in humans, plants, and bacteria and is critical for the smooth operation of its host cell. It is also a very convincing Death Star look-a-like.
In times of cellular stress (such as an increase in temperature), proteins will eventually struggle to carry out their normal function. If left untreated these damaged proteins will aggregate, often resulting in cellular death. But these cells are not going to give up so easily - they have a contingency plan. This contingency plan is in the form of HtrA, a protein that is enlisted to return cellular order and control and ultimately ensure their continued survival.
HtrA does this by carrying out one of two functions: it either repairs damaged proteins enabling them to continue to perform their cellular role, or it destroys them completely. Its ability to perform these seemingly antagonistic roles of both ‘repairer’ and ‘destroyer’ is quite remarkable and is a capability that is rarely seen in a single protein.
Also unique, is its ability to form cage-like structures like the one shown above. Amazingly these ‘super-structures’ are actually comprised of 24 individual HtrA proteins that, upon sensing cellular stress signals, immediately mobilise around damaged proteins and effectively hold them captive while performing their repair/destroy function.
Cells should therefore feel safe in the knowledge that HtrA is there to protect them in times of stress - whether its by nursing damaged proteins back to health, or destroying them completely like its Star Wars equivalent would certainly do.