Intracellular Signalling Pathways 2 Flashcards
What are the 2 types of GPCR effectors? Give an example of each
Enzymes - Adenylyl Cyclase (ATP > cAMP)
- Phospholipase (PIP2 > IP3 + DAG)
Ion Channels - Voltage operated calcium channels
- G-Protein regulated K+ channels
How is Adenylyl Cyclase stimulated?
- Alpha subunit binds to Adenylyl Cyclase
- Binding activates or inactivates the enzyme
- ATP can be converted to cAMP if activated
- cAMP activates protein kinase (PKA)
Name a Gs Receptor
- Beta-adrenoceptor
- D1-dopamine receptor
- H2-histamine receptor
Name a Gi receptor
- Alpha2 adrenoceptor
- D2 dopamine receptor
- mew-opioid receptor
What are the two domains in enzyme action?
- Catalytic Domain
- Regulatory Domain
What happens when cAMP binds to a regulatory domain?
The catalytic subunits are released and phosphorylase target proteins in the cell
How many products does Phospholipase C produce?
2
What is the effect of Phospholipase C on a cell?
Allows calcium to move down a concentration gradient from endoplasmic reticulum into the cell
What molecule contributes most to signal amplification?
Enzymes
Name 3 signalling pathways
- Heart Inotropy
- Smooth Muscle Contraction
- Neurotransmitter Release
How is Heart Inotropy increased?
cAMP activates more PKA which opens the voltage operated calcium channel
Name two chemicals and their effect on smooth muscle contraction
Noradrenaline > Vasoconstriction
Acetylcholine > Bronchoconstriction
How is neurotransmitter release decreased?
Morphine can inhibit calcium channels reducing calcium influx and neurotransmitter release
