Keima-Red Research Reagents for Detecting Mitophagy
Mitophagy is the selective degradation of old or depolarized mitochondria by autophagy and contributes to maintaining a healthy population of mitochondria. Since damaged mitochondria lead to collapse cell homoeostasis, mitophagy is believed to be protective against diseases related to mitochondrial dysfunction such as in neurodegenerative disorders.
Parkin, an ubiquitin ligase known as the gene responsible for Parkinson’s disease, plays an important role in the autophagic elimination of mitophagy. When mitochondria are depolarized and dysfunctional, PTEN-induced putative kinase protein 1 (PINK1) accumulates on the outer membrane and recruits Parkin on the damaged mitochondria. The outer membrane on the mitochondria is then ubiquitinated through the ubiquitin ligase activity of Parkin. Finally, the poly-ubiquitinated mitochondria are selectively recognized and executed by the autophagic process.
The fluorescent protein Keima has an excitation spectrum that changes according to pH. A short wavelength (440 nm) is predominant for excitation in a neutral environment, whereas a long wavelength (586 nm) is predominant in an acidic environment. The ratio of fluorescent intensity in each excitation condition is an indicator of mitophagy in living cells.