proteasomeinteracting

Proteasome-interacting refers to proteins and factors that bind directly to the proteasome complex and influence its activity, assembly, localization, or substrate processing. The term covers a diverse set of partners that modulate how the proteasome recognizes, unfolds, and degrades proteins within the ubiquitin-proteasome system.

The proteasome is a large protease responsible for the regulated turnover of most intracellular proteins. Interactors can bind to the 20S core particle, the 19S regulatory particle, or to alternative regulators such as the PA28/11S activators. These interactions can alter proteasome activity, substrate delivery, or proteolytic efficiency, and can also affect the assembly and stability of the proteasome complex.

Interactors can be broadly grouped into categories. Regulatory and adaptor proteins help recruit specific substrates to the proteasome or modulate degradation rates. Deubiquitinases associated with the proteasome, such as USP14 and UCH37, edit ubiquitin chains and influence substrate commitment. Ubiquitin receptors on the proteasome, like Rpn10 and Rpn13, participate in substrate recognition. Proteasome inhibitors and chaperones also fall into this category, contributing to fine-tuning of proteasomal proteolysis.

Biological significance is wide, including roles in protein quality control, cell cycle regulation, stress response, and antigen processing for immune surveillance. Because proteasome function is central to proteostasis, abnormalities in proteasome-interacting proteins are linked to diseases such as cancer and neurodegenerative disorders. Some interactors are explored as therapeutic targets to modulate proteasome activity and protein degradation. The study of proteasome-interacting proteins continues to illuminate how cells regulate proteolysis in health and disease.