Receptors and signal transduction II Flashcards
Differences between same ionotropic receptor w/ diff subunit makeup?
gating frequencies, desensitisation rates, ion permeabilities
How can subunit diversity be used for theraputics?
Can use drugs to target a certain subunit makeup of a receptor–> make it more specific
What may cause a receptors subunit makeup to be a specific way?
Locatio–> e.g. receptors in one area of the nervous system may have a diff subunit makeup to receptors in another area
What are AMPA, NMDA, KAINATE used for?
Synthetic ligands that allow us to experimentally distinguish between the subclasses of glutamate receptors
AMPA receptor subunits?
GluA1-GluA4
What are most AMPA receptors (hetero/homo)?
Heteromeric, tho some homomeric are possible
What do most AMPA glutamate channels allow to pass through?
Na+
Which ion can some AMPA receptors allow through?
Ca2+
How can an AMPA glutamate receptor allow Ca2+ through?
If it lacks GluA2
Why does GluA2 prevent Ca2+ from passing through an AMPA channel?
It is not permeable to calcium
Why are most AMPA receptors not calcium permeable?
They contain GluA2
What ions do NMDA channels allow through?
Na+ and Ca2+
NMDA subunits?
GluN1, GluN2A-D, GluN3A and GluN3B
What are NMDA receptors (hetero/homo)?
Obligate heteromers
What is an obligate heteromer?
Must have diff subunit types
KAINATE receptor subunits?
GluK1–>5
Where are most KAINATE receptors found?
Nerve terminal (Pre N)
What are the Cys-loop receptors?
GABAa, glycine, nACh, 5HT
Why are the Cys-loop receptors called that?
All have a common cys-loop in their structure
What is essentially the only trimeric ligand gated ion channel?
Purines
Where is the cys loop found?
Located in N terminus of the receptor
What role does the cys-loop play?
Coupling against binding to channel opening
What type of channel are all of the cys-loop ones?
Pentameric
Two classes of glutamate receptors?
Ionotropic and metabotropic
Ionotropic glutamate receptors?
NMDA, AMPA, KAINATE
Metabotropic glutamate receptors?
I, II, III
NMDA receptor ion permeability?
Na+ and Ca2+
AMPA and KAINATE receptor permeability?
Primarily Na+ but also Ca2+
Class I metabotropic glutamate receptor effect?
Upregulation of IP3 and Ca2+–> can drive calcium transients
Which cells are class I metabotropic glutamate receptors found in?
Glial cells–> allows calcium waves to pass through the glial population
Effect of class II and III metabotropic glutamate receptors?
Reduce cAMP via inhibitory g proteins
What are II and III glutamate receptors classified as?
Autoreceptors–> regulate glutamate release
Where do class II and III glutamate receptor exist?
Nerve terminal
