This is a very complex subject, so as usual I will try to stick to the essentials to make things as clear as possible, while details can be dealt with in the discussion. It is difficult to define exactly the role of the Ubiquitin System. It is usually considered mainly a pathway which regulates protein degradation, but in reality its functions are much wider than that. In essence, the US is a complex biological system which targets many different types of proteins for different final fates. The most common “fate” is degradation of the protein. In that sense, the Ubiquitin System works together with another extremely complex cellular system, the proteasome. In brief, the Ubiquitin System “marks” proteins for degradation, … Continue reading The Ubiquitin System: Functional Complexity and Semiosis joined together.