Item

Abstract

Proteins are composed of linear chains of amino acids. Upon synthesis in the cell, most proteins must rapidly acquire a specific three-dimensional structure, a process known as folding, before they can perform their various biological func- tions. Productive folding is often competed by aggregation, owing to the high macromolecular crowding of the cellular environment. Moreover, the process of translation increases the danger of misfolding, as incomplete nascent polypeptides are not yet able to fold into stable structures in many cases. To avoid these off-pathway reactions, a class of proteins called molecular chaperones has evolved in all organisms. They interact with nascent or stress-denatured polypeptides, prevent their aggregation and assist in folding and assem- bly processes, often in an ATP-regulated manner. These functions are especially important in condi- tions of cell stress, and their failure is linked with the manifestation of numerous age-dependent degenerative diseases