Related Experiment Video

Updated: Jun 1, 2026

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

A yeast BH3-only protein mediates the mitochondrial pathway of apoptosis

Sabrina Büttner1, Doris Ruli, F-Nora Vögtle

  • 1Institute of Molecular Biosciences, University of Graz, Graz, Austria.

The EMBO Journal
|June 16, 2011
PubMed

Insights

Researchers discovered a yeast protein, Ybh3p, with a functional BH3 domain that triggers apoptosis. This discovery reveals conserved cell death mechanisms across species and extends yeast lifespan.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Genetics

Background:

  • Apoptosis, or programmed cell death, is crucial for development and tissue homeostasis.
  • The BCL-2 family of proteins regulates apoptosis by controlling mitochondrial outer membrane permeabilization.
  • BH3 domains are key functional motifs within BCL-2 family proteins, mediating interactions and apoptosis signaling.

Purpose of the Study:

  • To identify and characterize novel proteins with functional BH3 domains in yeast.
  • To investigate the role of Ybh3p in apoptosis and its interaction with mitochondrial components.
  • To explore the evolutionary conservation of BH3 domain-mediated apoptosis.

Main Methods:

  • Yeast two-hybrid screening to identify interacting proteins.
  • Mitochondrial localization studies using fluorescence microscopy.
  • Analysis of apoptosis induction and mitochondrial membrane potential.
  • Gene deletion and knockdown experiments in yeast and human cells.

Main Results:

  • A novel yeast protein, Ybh3p, containing a functional BH3 domain was identified.
  • Ybh3p translocates to mitochondria upon lethal insult, inducing apoptosis in a BH3-dependent manner.
  • Ybh3p-induced apoptosis and mitochondrial disruption require the mitochondrial phosphate carrier Mir1p.
  • Deletion of YBH3 in yeast resulted in increased lifespan and resistance to apoptosis.

Conclusions:

  • The yeast genome encodes a functional BH3 domain protein (Ybh3p) that can induce cell death.
  • Ybh3p utilizes phylogenetically conserved mechanisms involving mitochondrial targeting and Mir1p for apoptosis induction.
  • The findings suggest a conserved role for BH3 domain proteins in regulating cell death across eukaryotes.

More Related Videos

Activation of Apoptosis by Cytoplasmic Microinjection of Cytochrome c07:42

Activation of Apoptosis by Cytoplasmic Microinjection of Cytochrome c

Published on: June 29, 2011

Mitochondrial Transformation in Baker's Yeast to Study Translation and Respiratory Complex Assembly09:53

Mitochondrial Transformation in Baker's Yeast to Study Translation and Respiratory Complex Assembly

Published on: June 7, 2024

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...
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 reduction of the tissue.
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...
Caspases01:24

Caspases

Caspase, a family of cysteine proteases, serve as effectors in apoptosis. The ced3 gene in C.elegans was first identified to be involved in apoptosis. This gene encodes the ced-3 caspase that is similar to the interleukin-1-beta converting enzyme or ICE in mammals. In addition to apoptosis, caspases also function in the inflammatory response. Inflammatory caspases are essential in activating pro-inflammatory cytokines that recruit immune cells and block the replication of pathogens inside cells.
Cellular Injury V: Apoptosis and Autophagy01:22

Cellular Injury V: Apoptosis and Autophagy

Cells respond to damage and stress through highly coordinated processes that decide whether they survive or undergo controlled self-destruction. Two major pathways involved in this regulation are apoptosis, a type of programmed cell death, and autophagy, a survival mechanism that helps cells adapt to adverse conditions.ApoptosisApoptosis removes aged or injured cells to maintain tissue balance. During this process, the cell shrinks, chromatin condenses and fragments, and membrane-bound...
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 pro-apoptotic...