Related Experiment Video
Updated: Jun 15, 2026
10:36
Measurements of Physiological Stress Responses in C. Elegans
Published on: May 21, 2020
MAPK scaffolding by BIT1 in the Golgi complex modulates stress resistance
Ping Yi1, Duc Thang Nguyên, Arisa Higa-Nishiyama
1Avenir, INSERM U889, Bordeaux, France.
Journal of Cell Science
|March 4, 2010
Summary
Researchers identified mitochondrial Bcl-2 inhibitor of transcription (BIT1) in the endoplasmic reticulum (ER) and Golgi. This discovery reveals BIT1
Area of Science:
- Cell Biology
- Molecular Biology
- Biochemistry
Background:
- The endoplasmic reticulum (ER) is crucial for protein folding and transport.
- ER-resident molecular machines may be regulated by their membrane environment.
- Investigating ER microdomains can uncover novel proteins involved in the secretory pathway.
Purpose of the Study:
- To characterize the proteome of ER-membrane microdomains.
- To identify novel ER components involved in secretory pathway functions.
- To understand the role of mitochondrial Bcl-2 inhibitor of transcription (BIT1) in the ER and Golgi.
Main Methods:
- Proteomic analysis of dog pancreatic rough microsomes.
- Localization studies of BIT1 within the secretory pathway.
- Chimeric protein expression to study BIT1 oligomerization and Golgi localization.
- Gene silencing to assess the impact of BIT1 on signaling pathways.
Main Results:
- Mitochondrial Bcl-2 inhibitor of transcription (BIT1) was found in the early secretory pathway and Golgi complex.
- Perturbing BIT1 oligomerization and Golgi localization enhanced ERK signaling.
- Enhanced ERK signaling from the Golgi resulted in improved stress resistance.
Conclusions:
- This study provides the first evidence for ER microdomains regulating BIT1 structure and trafficking.
- BIT1 is identified as a negative regulator of the ERK-MAPK signaling pathway in the Golgi.
- ER microdomains play a role in controlling secretory pathway-associated functions through proteins like BIT1.
Related Concept Videos
01:07MAPK Signaling Cascades
Mitogen-activated protein kinase, or MAPK pathway, activates three sequential kinases to regulate cellular responses such as proliferation, differentiation, survival, and apoptosis. The canonical MAPK pathway starts with a mitogen or growth factor binding to an RTK. The activated RTKs stimulate Ras, which recruits Raf or MAP3 Kinase (MAPKKK), the first kinase of the MAPK signaling cascade. Raf further phosphorylates and activates MEK or MAP2 Kinases (MAPKK), which in turn phosphorylates MAP...
01:42Microtubule Associated Proteins (MAPs)
Microtubule function and architecture are regulated by an array of specialized proteins called microtubule-associated proteins or MAPs. These proteins are widespread across different organisms and have conserved protein motifs, like the multi-TOG domain for tubulin binding found in the CLASP family of MAPs. Some MAPs are lineage-specific based on their conserved domains. Their functions depend upon the cytoskeletal architecture and cell type they are located within. In-plant cells, a specific...
01:30Other Stress Responses in Bacteria
Bacteria have global regulatory systems that control several types of stress mechanisms. These include Pho regulon and the heat shock response, which are essential systems for environmental adaptation, such as nutrient limitation and proteotoxic stress. The Pho regulon and the heat shock response exemplify bacterial resilience, enabling rapid adaptation to fluctuating environmental conditions.Pho RegulonBacteria require phosphorus for essential cellular processes, including nucleic acid...
01:22PI3K/mTOR/AKT Signaling Pathway
The mammalian target of rapamycin (mTOR) is a serine/threonine kinase that regulates growth, proliferation, and cell survival in response to hormones, growth factors, or nutrient availability. This kinase exists in two structurally and functionally distinct forms: mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2). The first form (mTORC1) is composed of a rapamycin-sensitive Raptor and proline-rich Akt substrate, PRAS40. In contrast, mTORC2 consists of a rapamycin-insensitive companion...
01:19Interactions Between Signaling Pathways
Signaling cascades usually lack linearity. Multiple pathways interact and regulate one another, allowing cells to integrate and respond to diverse environmental stimuli.
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
01:25cAMP-dependent Protein Kinase Pathways
Cyclic Adenosine Monophosphate (cAMP) is an essential second messenger that activates protein kinase A (PKA) and regulates various biological processes. A single epinephrine molecule binds to GPCR and activates several heterotrimeric G proteins, each stimulating multiple adenylyl cyclase, amplifying the signal, and synthesizing large numbers of cAMP molecules. Small changes in cAMP concentration affect PKA activity. The binding of four cAMP molecules induces a conformational change in PKA,...