Signaling #3 Flashcards
What are the key 2nd messengers involved in signal transduction?
cAMP and Ca2+
These are crucial for cellular signaling processes.
What influences the dispersion of receptors?
Lipid raft and PDZ domains
These structural features affect receptor localization and signaling.
Describe the basic structural features of G Protein-Coupled Receptors (GPCRs).
7 transmembrane domains
GPCRs have a characteristic structure that allows them to interact with ligands.
How are GPCRs activated?
By binding to ligands, leading to G-protein activation
This involves conformational changes in the receptor.
What is the role of adenylyl cyclase (AC) in GPCR signaling?
AC can be activated or inhibited by GPCRs
This affects the production of cAMP.
True or False: The same ligand can bind to multiple GPCRs.
True
This allows for diverse cellular responses.
What is Green Fluorescence Protein (GFP)?
A protein that fluoresces green when exposed to blue light
GFP is widely used as a biological marker.
What does Fluorescence Resonance Energy Transfer (FRET) measure?
Intermolecular interactions in real time
FRET requires donor and acceptor fluorophores to be within 10 nm proximity.
Fill in the blank: Blocking _______ adrenergic receptors can help with PTSD.
β2
This intervention targets emotional memory reinforcement.
What are some locations where olfactory receptors are found?
Skin, heart, lungs, kidneys, muscles, sperm
These receptors play roles beyond smell.
What is the significance of the 11-strand β-barrel in GFP?
It provides structural stability and fluorescence properties
This structure is essential for GFP’s function.
What is the main drawback of the Wild Type (Wt) GFP?
Poor photostability and pH sensitivity
These limitations affect its usability in some applications.
Describe the operational model for ligand-induced activation of GPCRs.
Involves GTP for GDP exchange to activate the α-subunit
This process is crucial for signal transduction.
What is the role of Propranolol?
It is a non-selective β-adrenergic receptor antagonist
Used to treat various cardiovascular conditions and anxiety.
How does FRET indicate interactions between proteins?
By measuring energy transfer between donor and acceptor fluorophores
A change in emission color signifies proximity.
What is the link between PTSD and GPCR signaling?
PTSD involves adrenaline release affecting GPCRs in the amygdala
This contributes to emotional processing and memory reinforcement.
How long does it take for GPCR activation to occur?
Within a few seconds
This rapid response is vital for cellular signaling.
What technique was used to show receptor-mediated activation of GPCR?
Fluorescence resonance energy transfer (FRET)
This technique allows observation of molecular interactions.
What is the significance of cadmium detection in zebrafish using GFP?
It indicates environmental stress through HSP70 promoter activation
This application highlights GFP’s use in environmental monitoring.
What hormone is linked to the release that affects the amygdala?
Adrenaline/epinephrine
Which area of the brain is involved in emotional processing?
Amygdala
What effect does the recurrence of fear have on memory?
Triggers release of adrenaline, reinforcing the memory further
What is the function of Propranolol in the context of PTSD?
Blocks β2 adrenergic receptors in the amygdala, believed to block memory reinforcement
True or False: Propranolol reduces the emotional charge associated with a traumatic memory.
True
What does Propranolol do when given during the reactivation of a traumatic memory?
Reduces the emotional intensity of the memory
What is the outcome of associating a traumatic memory with a less fearful version?
The memory can be re-stored back in the brain in an altered state
What is the role of de novo protein synthesis in memory reconsolidation?
Required for re-storing memories in a labile state
Fill in the blank: Propranolol is a pill to reduce the intensity of the _______.
Traumatic memory
What is the primary mechanism by which Propranolol treats hemangiomas?
Reduces vessel density
What happens to the color of hemangiomas during Propranolol treatment?
Changes in color, associated with palpable softening
What growth factor’s expression decreases due to Propranolol treatment?
Vascular endothelial growth factor (VEGF)
List some side effects of β-blockers.
- Transient hypoglycemia
- Bradycardia
- Hypotension
What does adenylyl cyclase convert ATP to?
cAMP and pyrophosphate
What role do caffeine and theophylline play regarding cAMP?
Inhibit cAMP phosphodiesterase
True or False: cAMP is rapidly hydrolyzed by cAMP phosphodiesterases.
True
