p62/SQSTM1 cooperates with Parkin for perinuclear clustering of depolarized mitochondria

K Okatsu, K Saisho, M Shimanuki, K Nakada… - Genes to …, 2010 - Wiley Online Library
K Okatsu, K Saisho, M Shimanuki, K Nakada, H Shitara, Y Sou, M Kimura, S Sato, N Hattori…
Genes to Cells, 2010Wiley Online Library
PINK1 and Parkin were first identified as the causal genes responsible for familial forms of
early‐onset Parkinson's disease (PD), a prevalent neurodegenerative disorder. PINK1
encodes a mitochondrial serine/threonine protein kinase, whereas Parkin encodes an
ubiquitin‐protein ligase. PINK1 and Parkin cooperate to maintain mitochondrial integrity;
however, the detailed molecular mechanism of how Parkin‐catalyzed ubiquitylation results
in mitochondrial integrity remains an enigma. In this study, we show that Parkin‐catalyzed …
PINK1 and Parkin were first identified as the causal genes responsible for familial forms of early‐onset Parkinson’s disease (PD), a prevalent neurodegenerative disorder. PINK1 encodes a mitochondrial serine/threonine protein kinase, whereas Parkin encodes an ubiquitin‐protein ligase. PINK1 and Parkin cooperate to maintain mitochondrial integrity; however, the detailed molecular mechanism of how Parkin‐catalyzed ubiquitylation results in mitochondrial integrity remains an enigma. In this study, we show that Parkin‐catalyzed K63‐linked polyubiquitylation of depolarized mitochondria resulted in ubiquitylated mitochondria being transported along microtubules to cluster in the perinuclear region, which was interfered by pathogenic mutations of Parkin. In addition, p62/SQSTM1 (hereafter referred to as p62) was recruited to depolarized mitochondria after Parkin‐directed ubiquitylation. Intriguingly, deletion of p62 in mouse embryonic fibroblasts resulted in a gross loss of mitochondrial perinuclear clustering but did not hinder mitochondrial degradation. Thus, p62 is required for ubiquitylation‐dependent clustering of damaged mitochondria, which resembles p62‐mediated ‘aggresome’ formation of misfolded/unfolded proteins after ubiquitylation.
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