Parkin is a ubiquitin E3 ligase, an enzyme that plays a crucial role in the process of ubiquitination, where small proteins known as ubiquitins are added to substrates to modify their function or earmark them for degradation. Ubiquitination is an essential post-translational modification process in cells, influencing various cellular pathways, including protein degradation, cell cycle regulation, DNA repair, and cellular signaling. Parkin, in particular, has garnered attention due to its role in maintaining mitochondrial integrity and function. It is involved in the identification and marking of damaged mitochondria for degradation, a process termed mitophagy. Proper functioning of Parkin is essential for cellular health, especially for neurons, which are highly dependent on efficient mitochondrial function.
Parkin inhibitors are chemical compounds designed to modulate or halt the activity of the Parkin enzyme. Given that Parkin's role is pivotal in mitochondrial homeostasis, compounds that inhibit its function can have profound effects on cellular physiology, especially in relation to mitochondrial health and dynamics. These inhibitors can act by binding directly to the active site of Parkin, preventing it from interacting with its substrates, or by altering its conformation in a way that its ubiquitin ligase activity is hindered.