Pharmacodynamics II: Membrane Receptors Flashcards
What are the FOUR main classes of receptors in cell signalling?
- Ligand-Gated Ion Channels - ionotropic
- G-Protein-Coupled Receptors - metabotropic
- Kinase-Linked Receptors
- Nuclear Receptors - intracellular
How many subunits do Ion Channels have?
4-5
Do Ion Channels have fast or slow communication?
Very fast (μs - ms)
What are SIX examples of receptors that use Ion Channels?
- Nicotinic Acetylcholine Receptor (nAChR)
- GABAa Receptor
- Glycine Receptor
- Glutamate Receptor
- 5-HT3 Receptor
- P2x Purine Receptor
How do G-Protein-Coupled Receptors work?
- Receptors linked to EFFECTORS
- Change intracellular level of second messenger via GTP-binding proteins (G-Proteins)
What are SIX examples of receptors that use G-Protein-Coupled Receptors?
- Muscarinic Acetylcholine Receptor (mAchR)
- GABAb Receptor
- Adrenoceptors
- Dopamine Receptors
- 5-HT2 (Serotonin) Receptor
- Histamine H2 Receptor
How many times does the G-Protein-Coupled Receptor span the membrane?
7 times
Which intracellular loop couples to G-Protein and determines selectivity?
Third
Where do SMALLER ligands bind on the G-Protein-Coupled Receptor?
Within helix structure
Where do LARGER ligands bind on the G-Protein-Coupled Receptor?
Extracellular surface
How does the Thrombin Receptor work?
- Receptor activated by protease cleavage of N-terminus domain
- Reveals a ‘tethered agonsit’
Which TWO subtypes of GPCR ACTIVATE specific receptors?
Gs and Gq
Which TWO subtypes of GPCR INHIBIT specific receptors?
Gi and Go
How long do GCPRs take to signal?
Seconds to minutes
What enzymes do secondary messengers on GCPRs activate?
Protein Kinases
* phosphorylate target proteins
