Parkin ubiquitination of Kindlin-2 enables mitochondria-associated metastasis suppression

Minjeong Yeon1, Irene Bertolini1, Ekta Agarwal1

  • 1Immunology, Microenvironment and Metastasis Program, The Wistar Institute, Philadelphia, Pennsylvania, USA.

Insights

Parkin ubiquitinates Kindlin-2 at mitochondria, suppressing tumor cell migration and invasion. This mechanism reveals how Parkin regulates metastasis, highlighting Kindlin-2 as a potent oncogene when deregulated.

Area of Science:

  • Cell Biology
  • Cancer Biology
  • Mitochondrial Biology

Background:

  • Mitochondria play crucial roles in cellular signaling, with implications in cancer development.
  • The precise mechanisms linking mitochondrial function to cancer progression remain largely unknown.

Purpose of the Study:

  • To elucidate the role of Parkin and Kindlin-2 in tumor cell behavior and metastasis.
  • To investigate the molecular mechanisms by which Parkin regulates Kindlin-2 stability and function.

Main Methods:

  • Co-immunoprecipitation to detect Parkin-Kindlin-2 complex formation.
  • Ubiquitination assays to identify ubiquitination sites and linkage types.
  • Cell migration and invasion assays.
  • Mitochondrial dynamics and focal adhesion turnover analysis.
  • Expression of ubiquitin-resistant Kindlin-2 mutants.
  • 3D organoid models for studying epithelial-mesenchymal transition (EMT).

Main Results:

  • Parkin forms a complex with Kindlin-2 at mitochondria in tumor cells.
  • Parkin ubiquitinates Kindlin-2 at Lys581 and Lys582, targeting it for proteasomal degradation.
  • Loss of Kindlin-2 impairs cell migration, invasion, and focal adhesion turnover by affecting mitochondrial dynamics.
  • Parkin-mediated ubiquitination of Kindlin-2 suppresses metastasis but does not affect proliferation or apoptosis.
  • Restoration of Kindlin-2 function via a ubiquitin-resistant mutant rescues migratory and invasive phenotypes.
  • Impaired Kindlin-2 ubiquitination drives oncogenic traits, including EMT, in mammary gland development models.

Conclusions:

  • Deregulated Kindlin-2 acts as a potent oncogene.
  • Parkin-mediated ubiquitination of Kindlin-2 at mitochondria is a key mechanism for suppressing tumor cell metastasis.
  • This pathway offers potential therapeutic targets for inhibiting cancer spread.

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