Related Experiment Video
Updated: May 26, 2026
11:13
Exploring the Pharmacological Action and Molecular Mechanism of Salidroside in Inhibiting MCF-7 Cell Proliferation and Migration
Published on: June 9, 2023
SS-A/Ro52 promotes apoptosis by regulating Bcl-2 production
Siti Nur Aisyah Jauharoh1, Jun Saegusa, Takeshi Sugimoto
1Department of Clinical Pathology and Immunology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan.
Biochemical and Biophysical Research Communications
|December 20, 2011
Summary
SS-A/Ro52 (Ro52) depletion enhances cell resistance to apoptosis from various stressors. This effect is mediated by upregulating the anti-apoptotic protein Bcl-2, independent of p53.
Area of Science:
- Molecular and Cellular Biology
- Immunology
- Biochemistry
Background:
- SS-A/Ro52 (Ro52) is an autoantigen implicated in systemic autoimmune diseases.
- Ro52 possesses E3 ligase activity, ubiquitinating proteins crucial for antiviral defense.
Purpose of the Study:
- To investigate the role of Ro52 in cellular stress response and apoptosis.
- To elucidate the molecular mechanisms underlying Ro52-mediated apoptosis.
Main Methods:
- Transient knockdown of Ro52 in HeLa cells using siRo52.
- Stimulation of cells with various apoptotic inducers (oxidative stress, interferons, irradiation, etc.).
- Analysis of apoptosis resistance, p53 protein levels, and Bcl-2 family protein expression.
Main Results:
- Ro52-depleted HeLa cells exhibited significantly increased resistance to apoptosis induced by diverse stressors.
- Ro52-mediated apoptosis was independent of p53 protein levels.
- Depletion of Ro52 led to upregulation of Bcl-2, but not other Bcl-2 family members.
Conclusions:
- Ro52 acts as a universal proapoptotic molecule.
- Ro52's proapoptotic function is exerted through negative regulation of Bcl-2, independent of p53.
- These findings reveal a novel physiological role for Ro52 in intracellular immunity.
Related Concept Videos
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...
01:17The 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...
01:22Cellular 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...
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.
01:24Caspases
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.
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...