Which of the following is a key characteristic of coat proteins?

Coat proteins are specialized proteins that play a crucial role in the formation and budding of vesicles from donor membranes. One of the key characteristics of coat proteins is their ability to assemble on the cytoplasmic surface of these membranes, which is essential for the process of vesicle budding. By coating the membrane, these proteins induce curvature that leads to the eventual formation of a vesicle.

Once the bud is formed, the coat proteins assist in the scission of the vesicle from the membrane, allowing it to transport its cargo to the appropriate location within the cell. This action is fundamental in various processes, including endocytosis and the transport of proteins from the Golgi apparatus to their destinations.

While the other options may describe different roles of proteins in cellular processes, they do not specifically pertain to the function of coat proteins in vesicle trafficking. For instance, protein degradation is a function associated with proteasomes and lysosomes, while the promotion of fusion with target membranes is typically the role of SNARE proteins. Receptor-binding capabilities are more aligned with membrane proteins or signaling molecules, rather than the function of coat proteins in vesicle formation.