Shedding light on apoptosis at subcellular membranes
Justin Kale1, Qian Liu, Brian Leber
1Department of Biochemistry, McMaster University, Hamilton, Ontario L8S 4L8, Canada.
Cell
|December 11, 2012
Summary
Fluorescence techniques illuminate complex interactions of Bcl-2 family proteins in apoptosis regulation. These methods advance understanding of protein-protein and protein-membrane systems in vitro, live cells, and animal models.
Area of Science:
- Biochemistry
- Molecular Biology
- Cell Biology
Background:
- Bcl-2 family proteins are key regulators of apoptosis.
- Their interactions involve complex protein-protein and protein-membrane systems.
- Understanding these mechanisms is crucial for cell death research.
Purpose of the Study:
- To highlight the role of fluorescence techniques in studying Bcl-2 family protein interactions.
- To demonstrate how these techniques enhance the elucidation of molecular mechanisms.
- To showcase the application of fluorescence in various biological contexts.
Main Methods:
- Utilizing fluorescence microscopy and spectroscopy.
- In vitro biochemical assays.
- Live-cell imaging and in vivo animal studies.
Main Results:
- Fluorescence techniques provide high resolution and sensitivity for observing molecular interactions.
- Detailed insights into protein dynamics and localization were obtained.
- The study demonstrates the versatility of fluorescence in dissecting complex biological systems.
Conclusions:
- Fluorescence techniques are indispensable tools for investigating apoptosis regulation by Bcl-2 family proteins.
- These methods significantly advance the understanding of protein-protein and protein-membrane interactions.
- Future research can leverage these techniques for further discoveries in cell death pathways.
Related Concept Videos
01:30Apoptosis
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.
01:17The 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...
01:31The 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...
01:17Phagocytosis 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 by phagocytes.
Normal cells contain receptors that prevent them from being recognized by phagocytes.
01:18Autophagic 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...
Autophagy and Apoptosis
Autophagy can activate apoptosis. In normal conditions, the autophagy activating protein Beclin-1 and pro-apoptotic...
01:22Cellular 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...