26Sproteasomi

The 26S proteasome is a type of proteasome that degrades proteins and plays a role in regulating protein turnover in the cell. Proteasomes are large protein complexes that are responsible for the degradation of ubiquitinated proteins, which are proteins that have been tagged with a ubiquitin molecule.

The 26S proteasome is named for its sedimentation coefficient, which is approximately 26S. It is composed of two subunits: a 20S proteolytic core, a large subunit known as RPN, and a small subunit known as RPT. The 20S core is responsible for the degradation of substrate proteins, while the RPN and RPT subunits provide additional functions, such as Regulated Interference with Proteolysis (RIP) box binding and the hydrolysis of ATP.

The 26S proteasome degrades proteins that are marked by ubiquitin or other proteins, such as Nedd8. The degradation of these proteins results in the removal of damaged or misfolded proteins, which are typically associated with various diseases, including neurodegenerative disorders and cancer. The 26S proteasome is also involved in the regulation of protein degradation and has been implicated in various cellular processes, including signal transduction and cell cycle regulation.

The 26S proteasome is crucial for the proper functioning of the cell, especially in the regulation of protein turnover. The subunits of the 26S proteasome interact with other proteins and proteins that bring ubiquitinated-proteins to it. The breakdown of the ubiquitinated proteins is what sets off the signal for various processes like degradation.