Phospho-Ubiquitin (Ser65) Cellular Kit, 500 Tests

The Phospho-Ubiquitin (Ser65) Cellular assay is designed to monitor the level of the phosphorylated form of the Ubiquitin chain. Ubiquitin itself is a 76 amino acid protein (8.5 kDa) that is ubiquitously expressed and highly conserved, with 100% AA sequence identity between human and mouse.

Phosphorylation of Ubiquitin is a key step in the process of mitochondria quality control through the Parkin/PINK-1 interaction. Parkin is a Ubiquitin ligase E3 that conjugates Ubiquitin to impaired-mitochondrial proteins, leading to organelle degradation. PINK1 is a Ser/Thr kinase that accumulates only on impaired mitochondria and phosphorylates two substrates, the Ubiquitin-like domain of Parkin and Ubiquitin chains.

The amplified Parkin/PINK-1 dependent Ubiquitin functions act as a signal for the sequestration and degradation of damaged mitochondria (mitophagy). Dysregulation of this signaling is linked to some forms of Parkinson's Disease.

Depolarization of mitochondria by uncoupling agents, such as CCCP and valinomycin, causes PINK1 to accumulate on the outer mitochondrial membrane and trigger PhosphoS65-Ubiquitin production.