Wrong place
When you reach a certain age, one question arises on a painfully regular basis. It begins with a "Where are my...?" or a "Where is my..." Reading glasses are a constant. Frequently, they are not where they ought to be. Having relocated them, you may well remark that they are not where you put them. But they are. The thing is, in a moment of distraction, you left them where you would not normally: on the garden wall, in your coat pocket, on the clothes washing machine, perhaps even in the fridge. All in all, they were inadvertently mislocated. On a far smaller scale, the same kind of thing can happen to proteins. There are times when proteins end up where they should not be - which is a source of stress both for their unusual environment and the one they have not reached. Over time, cells have developed various quality control systems to correct all sorts of mistakes - one of them being mislocation. As an illustration, lodged in the endoplasmic reticulum membrane, the enzyme P5A-ATPase is able to spot mislocated transmembrane mitochondrial proteins, grab hold of them and fling them back into the cellular cytosol.
