AbuArish_CPPS325_March10_2025_Lecture 2_upload (1) Flashcards
What is the concept of fluorescence?
The concept of fluorescence involves the emission of light by a substance that has absorbed light or other electromagnetic radiation.
What is the Jablonski Diagram?
The Jablonski Diagram is a graphical representation of the electronic states of a molecule and the transitions between them, illustrating processes like fluorescence.
Define a fluorescent molecule.
A fluorescent molecule is a compound that can absorb light at a certain wavelength and then emit light at a longer wavelength.
What is fluorescence confocal microscopy?
Fluorescence confocal microscopy is a technique that increases optical resolution and contrast by using a spatial pinhole to block out-of-focus light.
What is the resolution limit in fluorescence microscopy?
The resolution limit in fluorescence microscopy refers to the smallest distance between two points that can be distinguished as separate entities.
What does fluorescence super-resolution microscopy include?
Fluorescence super-resolution microscopy includes techniques such as STED (Stimulated Emission Depletion) microscopy.
What is Image Correlation Spectroscopy (ICS)?
Image Correlation Spectroscopy (ICS) is a technique used to quantify the behaviors of proteins in live cells by analyzing the correlation of fluorescent signals over time.
Why do we study protein behaviors in cells?
We study protein behaviors in cells to best understand protein function in health and disease, focusing on molecular behaviors.
What is CFTR?
CFTR stands for Cystic Fibrosis Transmembrane Conductance Regulator, which functions as an ion channel.
What is the significance of CFTR localization?
CFTR localization at the plasma membrane is essential for its function as an ion channel, and its loss is associated with cystic fibrosis.
What is the effect of cholesterol and ceramide lipids on CFTR?
Cholesterol and ceramide lipids modulate CFTR distribution and stability at the plasma membrane of bronchial epithelial cells.
What happens to CFTR concentration in cystic fibrosis?
In cystic fibrosis, only 5% of mutant CFTR (ΔF508-CFTR) is trafficked to the plasma membrane, reducing its concentration and function.
What is the impact of CFTR dysfunction?
CFTR dysfunction leads to diminished ion conductance and disrupted water secretion, resulting in thickened mucus and impaired mucociliary clearance.
What changes occur in CFTR distribution after stimulation?
Stimulation of CFTR function causes small clusters to coalesce into large platforms, indicating a change in distribution associated with altered function.
What are the two mobility states of CFTR observed in live cell imaging?
The two mobility states of CFTR are fast diffusive mobility and slow diffusive mobility, with the latter occurring when proteins are confined inside microdomains.
What is the role of airway surface liquid (ASL)?
Airway surface liquid (ASL) is important for mucus hydration and mucociliary clearance, which helps maintain airway health.
What is the definition of a diffusion coefficient (D)?
The diffusion coefficient (D) is defined as the area covered by particles divided by time.
What is the relationship between CFTR and cholesterol?
CFTR and cholesterol colocalize at the plasma membrane, suggesting that CFTR clustering is modulated by cholesterol.
True or False: CFTR is primarily localized in the nucleus.
False
Fill in the blank: The main function of CFTR is to conduct _______.
Cl- and HCO3-
What are the consequences of CFTR dysfunction in cystic fibrosis?
Consequences include acidic airway surface liquid, thickened mucus, impaired mucociliary clearance, and increased risk of bacterial infections.
What are lipid rafts?
Lipid rafts are microdomains within the plasma membrane that are enriched in cholesterol and sphingomyelin, playing roles in protein localization and signaling.
How are protein interactions with other proteins characterized?
Protein interactions can be characterized by their localization, distribution, and mobility in different cellular environments.
What are lipid rafts enriched in?
Cholesterol and sphingomyelin
Lipid rafts are specialized membrane domains that play a crucial role in cellular signaling and protein distribution.
What is the effect of cholesterol oxidation on CFTR?
Reduces CFTR confinement and clustering
CFTR stands for Cystic Fibrosis Transmembrane Conductance Regulator, a protein that regulates ion transport across epithelial membranes.
What happens to CFTR cluster size with increased membrane cholesterol?
Increases CFTR cluster size
Cholesterol esterification by CEase contributes to maintaining lipid raft integrity.
How does CFTR clustering relate to membrane stability?
Increases stability at the plasma membrane by reducing internalization
CFTR clustering inside lipid rafts influences its functional stability.
What role does ceramide play in CFTR membrane distribution?
Modulates CFTR membrane distribution
Ceramide-rich platforms are crucial for CFTR aggregation and function.
What is the impact of thapsigargin on CFTR?
Acts as a cell stressor
Thapsigargin is known to induce endoplasmic reticulum stress.
What is the relationship between reactive oxygen species (ROS) and ASMase?
VIP leads to ROS generation, activating ASMase
ASMase is an enzyme that generates ceramide from sphingomyelin.
What is the function of methyl-β-cyclodextrin (MβCD)?
Extracts cholesterol from the membrane and disrupts lipid rafts
MβCD is commonly used in experiments to study lipid raft dynamics.
What are the two populations of CFTR observed in confocal images?
Diffuse and clusters
These populations indicate different states of CFTR aggregation and membrane localization.
Fill in the blank: CFTR clustering is modulated by _______.
cholesterol
True or False: Intact lipid rafts are essential for platform formation.
True
The integrity of lipid rafts is necessary for proper protein localization and function.
What do ceramide-rich platforms increase in terms of CFTR?
Recruitment and tethering at the plasma membrane
This leads to enhanced expression and stability of CFTR.
What type of analysis is ideal for measuring CFTR molecular behaviors at the plasma membrane?
ICS analysis
ICS stands for Imaging Correlation Spectroscopy, which provides insights into protein dynamics.
What happens to sphingomyelin when ASMase is activated?
It is hydrolyzed into ceramide
This process is essential for the formation of ceramide-rich platforms.
What is the primary focus of Abu-Arish et al.’s 2019 study?
The modulation of CFTR membrane distribution by ceramide
This study emphasizes the role of lipids in protein localization.
What does the term ‘coalescence’ refer to in the context of lipid rafts?
The merging of lipid raft components to form larger platforms
Coalescence is important for the stability and function of membrane proteins.
