Parkin drives pS65-Ub turnover independently of canonical autophagy in Drosophila

ABSTRACT: Parkinson's disease-related proteins, PINK1 and Parkin, act in a common pathway to maintain mitochondrial quality control. While the PINK1-Parkin pathway can promote autophagic mitochondrial turnover (mitophagy) following mitochondrial toxification in cell culture, alternative quality control pathways are suggested. To analyse the mechanisms by which the PINK1-Parkin pathway operates in vivo, we developed methods to detect Ser65-phosphorylated ubiquitin (pS65-Ub) in Drosophila. Exposure to the oxidant paraquat led to robust, Pink1-dependent pS65-Ub production, while pS65-Ub accumulates in unstimulated parkin-null flies, consistent with blocked degradation. Additionally, we show that pS65-Ub specifically accumulates on disrupted mitochondria in vivo. Depletion of the core autophagy proteins Atg1, Atg5 and Atg8a did not cause pS65-Ub accumulation to the same extent as loss of parkin, and overexpression of parkin promoted turnover of both basal and paraquat-induced pS65-Ub in an Atg5-null background. Thus, we have established that pS65-Ub immuno-detection can be used to analyse Pink1-parkin function in vivo as an alternative to reporter constructs. Moreover, our findings suggest that the Pink1-parkin pathway can promote mitochondrial turnover independently of canonical autophagy in vivo.

SUBMITTER: Dr. Joanne, L Usher 

PROVIDER: S-SCDT-EMBOR-2021-53552-T | biostudies-other |

REPOSITORIES: biostudies-other