Related Experiment Video

Updated: Dec 17, 2025

Activation of Apoptosis by Cytoplasmic Microinjection of Cytochrome c
07:42

Activation of Apoptosis by Cytoplasmic Microinjection of Cytochrome c

Published on: June 29, 2011

17.7K

Deadly Encounter: Endosomes Meet Mitochondria to Initiate Apoptosis

Mariella Vicinanza1, David C Rubinsztein1

  • 1Cambridge Institute for Medical Research, Department of Medical Genetics, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK; UK Dementia Research Institute, Cambridge BioMedical Campus, The Keith Peters Building, Hills Road, Cambridge CB2 0XY, UK.

Developmental Cell
|June 24, 2020
PubMed

Insights

Apoptotic cell death relies on mitochondrial outer membrane permeabilization (MOMP). New research shows endosomes accumulating on mitochondria trigger lipid changes, aiding MOMP pore formation.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Biochemistry

Background:

  • Mitochondrial outer membrane permeabilization (MOMP) is a critical step in programmed cell death (apoptosis).
  • The precise mechanisms regulating the full execution of MOMP are not completely understood.
  • Endosomes are known to play roles in various cellular processes, but their involvement in MOMP is less explored.

Purpose of the Study:

  • To investigate the role of endosomes in the execution of MOMP.
  • To identify molecular interactions that facilitate MOMP.
  • To understand how mitochondrial lipid alterations contribute to apoptotic pore assembly.

Main Methods:

  • Cellular imaging techniques to observe mitochondria and endosomes during apoptosis.
  • Biochemical assays to analyze mitochondrial lipid composition.
  • Co-immunoprecipitation to identify protein interactions between endosomes and mitochondria.

Main Results:

  • Endosomes were observed to accumulate on mitochondria undergoing MOMP.
  • This accumulation led to significant alterations in mitochondrial lipid profiles.
  • A novel interaction was identified that links endosome accumulation to mitochondrial lipid changes, facilitating pore formation.

Conclusions:

  • Endosome accumulation on apoptotic mitochondria is essential for the complete execution of MOMP.
  • Mitochondrial lipid alterations induced by endosomes are key events in functional pore assembly.
  • This study reveals a new mechanism controlling a critical step in programmed cell death.

More Related Videos

Isolation and Functional Analysis of Mitochondria from Cultured Cells and Mouse Tissue09:27

Isolation and Functional Analysis of Mitochondria from Cultured Cells and Mouse Tissue

Published on: March 23, 2015

40.3K
Detection of Mitochondria Membrane Potential to Study CLIC4 Knockdown-induced HN4 Cell Apoptosis In Vitro13:20

Detection of Mitochondria Membrane Potential to Study CLIC4 Knockdown-induced HN4 Cell Apoptosis In Vitro

Published on: July 17, 2018

10.7K

Related Concept Videos

The Intrinsic Apoptotic Pathway01:31

The Intrinsic Apoptotic Pathway

Internal cellular stress, such as cellular injury or hypoxia, triggers intrinsic apoptosis. The B-cell lymphoma 2 (Bcl-2) family of proteins are the primary regulators of the intrinsic apoptotic pathway. For example, during DNA damage, checkpoint proteins, such as Ataxia Telangiectasia Mutated (ATM protein) and Checkpoints Factor-2 (Chk2) proteins, are activated. These proteins phosphorylate p53 which further activates pro-apoptotic proteins, such as Bax, Bak, PUMA, and Noxa, and inhibits...
8.0K
Apoptosis01:30

Apoptosis

Apoptosis is a combination of two Greek words, 'apo' and 'ptosis,' meaning separation and falling off, respectively. Hippocrates used this word to describe gangrene, which was caused due to bandaging of fractured bones. Apoptosis was distinguished from necrosis in 1970 when John Kerr reported observations of morphological changes occurring during apoptosis. During one experiment, he observed that the disruption of blood supply to the liver tissue resulted in a size...
13.5K
The Extrinsic Apoptotic Pathway01:17

The Extrinsic Apoptotic Pathway

The extrinsic apoptotic pathway is initiated when extracellular death-inducing signals, such as specific cytokines, activate the death receptors expressed on the cell surface. The immune cells involved in this pathway are natural killer cells (NK cells) and cytotoxic T-lymphocytes. NK cells are critical in innate immune response, while cytotoxic T-lymphocytes are associated with adaptive immune response. These cells recognize specific receptors expressed on the altered cells and activate...
7.8K
Autophagic Cell Death01:18

Autophagic Cell Death

Christian de Duve discovered “autophagy,” a process in which cellular components are engulfed by membrane-bound organelles called autophagosomes. The autophagosomes then fuse with lysosomes to digest the enclosed contents. Autophagy is generally activated in cells to prevent cell death. However, cell death is triggered when the damage is beyond repair.
Autophagy and Apoptosis
Autophagy can activate apoptosis. In normal conditions, the autophagy activating protein Beclin-1 and...
4.1K
Phagocytosis of Apoptotic Cells01:17

Phagocytosis of Apoptotic Cells

Cells undergoing apoptosis form apoptotic bodies that must be removed immediately to prevent inflammation, autoimmune diseases, and necrosis. Phagocytosis is carried out by professional phagocytes such as macrophages or  immature dendritic cells. Non-professional phagocytes such as  epithelial cells and fibroblasts also take part in this process; however, they are not as effective as professional phagocytes. 
Normal cells contain receptors that prevent them from being recognized...
4.6K
Mitochondrial Membranes01:45

Mitochondrial Membranes

A single mitochondrion is a bean-shaped organelle enclosed by a double-membrane system. The outer membrane of mitochondria is smooth and contains many porins - the integral membrane transporters. Porins enable free diffusion of ions and small uncharged molecules through the outer mitochondrial membrane but limit the transport of molecules larger than 5000 Daltons. Further, the outer mitochondrial membrane forms a unique structure called membrane contact sites with other subcellular organelles,...
16.3K