FORUM REVIEW ARTICLE Harnessing Proteasome Dynamics and Allostery in Drug Design

Significance: The proteasome is the essential protease that is responsible for regulated cleavage of the bulk of intracellular proteins. Its central role in cellular physiology has been exploited in therapies against aggressive cancers where proteasome-specific competitive inhibitors that block proteasome active centers are very ef-fectively used. However, drugs regulating this essential protease are likely to have broader clinical usefulness. The non-catalytic sites of the proteasome emerge as an attractive alternative target in search of highly specific and diverse proteasome regulators. Recent Advances: Crystallographic models of the proteasome leave the false impression of fixed structures with minimal molecular dynamics lacking long-distance allosteric signaling. However, accumulating biochemical and structural observations strongly support the notion that the proteasome is regulated by precise allosteric interactions arising from protein dynamics, encouraging the active search for allosteric regulators. Here, we discuss properties of several promising compounds that affect substrate gating and processing in antechambers, and interactions of the catalytic core with regulatory proteins. Critical Issues: Given the structural complexity of proteasome assemblies, it is a painstaking process to better understand their allosteric regulation and molecular dynamics. Here, we discuss the challenges and achievements in this field. We place special emphasis on the role of atomic force microscopy imaging in probing the allostery an