Balancing life and death: BCL-2 family members at diverse ER-mitochondrial contact sites

Related Experiment Video

Updated: Oct 16, 2025

Examining BCL-2 Family Function with Large Unilamellar Vesicles
08:35

Examining BCL-2 Family Function with Large Unilamellar Vesicles

Published on: October 5, 2012

8.1K

Robert E Means1, Samuel G Katz1

  • 1Department of Pathology, Yale University School of Medicine, New Haven, CT, USA.

The FEBS Journal
|October 20, 2021
PubMed

Insights

Mitochondrial-associated membranes (MAMs) are crucial signaling hubs. This review explores how BCL-2 family proteins regulate MAM structure, function, and cellular homeostasis, impacting cell survival and death.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Biochemistry

Background:

  • The outer mitochondrial membrane is vital for cellular survival, with BCL-2 family proteins regulating its integrity.
  • Mitochondrial-associated membranes (MAMs), sites of close endoplasmic reticulum-mitochondria apposition, are key signaling hubs.
  • MAMs are increasingly recognized as specialized subtypes involved in diverse cellular processes.

Purpose of the Study:

  • To review the diverse subsets of MAMs and their roles in cellular homeostasis.
  • To elucidate the contribution of BCL-2 family proteins to MAM structure and function.
  • To highlight the involvement of BCL-2 proteins in regulating cellular survival and death pathways at MAMs.

Main Methods:

  • Literature review and synthesis of existing research on MAMs and BCL-2 family proteins.
  • Analysis of the structural and functional roles of BCL-2 family members within MAMs.
  • Evaluation of the impact of BCL-2 proteins on cellular homeostasis and signaling at MAMs.

Main Results:

  • MAMs are specialized compartments with distinct functions, acting as critical signaling hubs.
  • BCL-2 family proteins, including BOK, are integral components of MAMs, influencing their structure and function.
  • Multiple BCL-2 proteins play significant roles in regulating cellular survival and death pathways localized to MAMs.

Conclusions:

  • MAMs are essential for cellular homeostasis, with BCL-2 family proteins playing multifaceted roles.
  • The localization and function of BCL-2 proteins within MAMs are critical for regulating cell fate.
  • Further research into BCL-2 family members in MAMs will deepen our understanding of cell survival and death.
Keywords:
BCL-2BOKapoptosisendoplasmic reticulummitochondrial-associated membranes

More Related Videos

Author Spotlight: Unveiling Mitochondrial Contact Sites and Architectural Insights07:55

Author Spotlight: Unveiling Mitochondrial Contact Sites and Architectural Insights

Published on: June 16, 2023

1.6K
Author Spotlight: Regulation and Dysregulation of ER-Mitochondria Contacts — Implications for Neurodegenerative Disease Pathogenesis09:09

Author Spotlight: Regulation and Dysregulation of ER-Mitochondria Contacts — Implications for Neurodegenerative Disease Pathogenesis

Published on: October 11, 2024

2.7K

Related Concept Videos

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,...
13.1K
Electron Transport Chain: Complex I and II01:46

Electron Transport Chain: Complex I and II

The mitochondrial electron transport chain (ETC) is the main energy generation system in the eukaryotic cells. However, mitochondria also produce cytotoxic reactive oxygen species (ROS) due to the large electron flow during oxidative phosphorylation. While Complex I is one of the primary sources of superoxide radicals, ROS production by Complex II is uncommon and may only be observed in cancer cells with mutated complexes.
ROS generation is regulated and maintained at moderate levels necessary...
15.3K
Translocation of Proteins into the Mitochondria01:19

Translocation of Proteins into the Mitochondria

Mitochondrial precursors are translocated to the internal subcompartments via independent mechanisms involving distinct protein machineries called translocases.
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
8.2K
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...
7.1K
Mitochondrial Protein Sorting01:39

Mitochondrial Protein Sorting

Mitochondria are double-membrane organelles of the eukaryotes involved in cellular metabolism, signaling, ATP synthesis, and programmed cell death.  Each of these processes requires specific proteins and enzymes that must be correctly sorted to the right mitochondrial subcompartment for the proper functioning of the organelle.
Most of these mitochondrial proteins are encoded by the nucleus and imported to the mitochondria as unfolded or loosely folded precursors. Mitochondrial precursors...
4.7K
The Inner Mitochondrial Membrane01:28

The Inner Mitochondrial Membrane

The inner mitochondrial membrane is the primary site of ATP synthesis. The inner membrane domain that forms a smooth layer adjacent to the outer membrane is called the inner boundary membrane. This domain contains membrane transporters that drive metabolites in and out of the mitochondria.  In contrast, the inner membrane network that invaginates into the matrix space is called the cristae membrane. This domain accounts for principle mitochondrial function as it accommodates the protein...
3.9K