Structural Basis of Tom1-Tollip Complex Assembly in Directing Parkin Perinuclear Clustering on Depolarized Mitochondria

Efficient elimination of dysfunctional mitochondria is a central aspect of mitochondrial quality control (MQC) and is essential for maintaining cellular homeostasis. This process relies on the E3 ubiquitin ligase Parkin, which is recruit by phos-ubiquitin and undergo critical spatial redistribution to cluster around damaged mitochondria in the perinuclear region. While Parkin's initial recruitment to depolarized mitochondria is well-studied, the molecular mechanisms that modulate its higher-order spatial organization and perinuclear clustering remain poorly defined. Here, we identify the Tom1-Tollip complex plays a pivotal role for Parkin clustering. By present the first high-resolution crystal structure of the Tom1/GAT-Tollip/TBD complex, we providing atomic-level insight into the stable assembly and functional architecture of this complex. We demonstrate that this complex is critical for MQC by facilitating Parkin into perinuclear clusters required for efficient mitochondrial enclosure and clearance. Loss of either Tom1 or Tollip, or disruption of their direct interaction, severely impairs Parkin's characteristic perinuclear clustering and obstructs damaged mitochondria elimination. Our findings illuminate a previously unappreciated function of the Tom1-Tollip complex in orchestrating the spatial organization of Parkin, thereby influencing the efficient clearance of damaged mitochondria during stress conditions.