Why and how protein aggregation has to be studied in vivo

The understanding of protein aggregation is a central issue in different fields of protein science, from the heterologous protein production in biotechnology to amyloid aggregation in several neurodegenerative and systemic diseases. To this goal, it became more and more evident the crucial relevance of studying protein aggregation in the complex cellular environment, since it allows to take into account the cellular components affecting protein aggregation, such as chaperones, proteases, and molecular crowding. Here, we discuss the use of several biochemical and biophysical approaches that can be employed to monitor protein aggregation within intact cells, focusing in particular on bacteria that are widely employed as microbial cell factories.