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Association of Omi/HtrA2 with γ-secretase in mitochondria

Homira Behbahani1, Pavel F Pavlov, Birgitta Wiehager

  • 1Karolinska Institutet and Dainippon Sumitomo Pharma Alzheimer Center (KASPAC), Department of Neurobiology, Care Sciences and Society (NVS), Karolinska Institutet, Huddinge, Sweden. homira.behbahani@ki.se

Neurochemistry International
|August 14, 2010
PubMed

Insights

Mitochondrial Omi/HtrA2 protease interacts with gamma-secretase complexes, impacting their activity. This finding offers insights into neurodegenerative disorders like Alzheimer's disease (AD).

Area of Science:

  • Mitochondrial biology
  • Neuroscience
  • Protease function

Background:

  • Omi/HtrA2 is a mitochondrial protease implicated in neurodegenerative disorders.
  • Gamma-secretase complexes are active within mitochondria.
  • Presenilin-1's C-terminus peptide activates Omi/HtrA2.

Purpose of the Study:

  • To investigate the interaction between Omi/HtrA2 and gamma-secretase complexes in mitochondria.
  • To determine the functional impact of Omi/HtrA2 on gamma-secretase activity.
  • To elucidate the role of this interplay in Alzheimer's disease (AD).

Main Methods:

  • Co-immunoprecipitation in isolated mitochondria.
  • Confocal microscopy using biotinylated gamma-secretase inhibitor.
  • Analysis of amyloid precursor protein intracellular domain (AICD) production.
  • Studies using Omi/HtrA2 knockout mouse embryonic fibroblasts.

Main Results:

  • Omi/HtrA2 interacts with presenilin within mitochondrial gamma-secretase complexes.
  • Gamma-secretase complexes associate with the outer mitochondrial membrane, with PS1 C-terminus exposed.
  • Omi/HtrA2 deficiency reduces AICD production, indicating its role in gamma-secretase activity.
  • Omi/HtrA2 influences gamma-secretase activity in mitochondria.

Conclusions:

  • Omi/HtrA2 and mitochondrial gamma-secretase complexes interact and influence each other's function.
  • This interaction is relevant to understanding the pathogenesis of Alzheimer's disease (AD).
  • Further research into this mitochondrial pathway may reveal new therapeutic targets for neurodegeneration.

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