KARs and structural basis of activation Flashcards
Which are faster, AMPARs or KARs?
AMPARs (but not by much)
What are two key properties of KARs?
Receptor summation
G protein coupled receptor
What is the difference between primary and secondary units of KARs? Which are which?
Primary units can form an ion channel on their own
Secondary units need at least one primary unit to form a pore
GluK1-3 are primary
GluK4-5 are secondary
Why are GluK4-5 secondary units?
They are more stubborn
Tetramers with only primary subunits have a typically ____ affinity as opposed to secondary subunits which have a ___ affinity
Lower
Higher
What are the 2 auxiliary subunits for Kaianate receptors?
Neto1 and 2
Rank the 3 receptor types in terms of their promiscuity
AMPARs are extremely promiscuous
KARs are the happy medium
NMDARs are extremely strict
What is PSD99 and how is it relevant to Receptors?
It lies under the cell and acts as a scaffolding, with several PDZ sites
Proteins with a PDZ binding site can latch onto it
What does the surface expression of KAR-neto complexes depend on?
Glu1/2/3 subunits
Why are Neto subunits important for KARs?
They allow for signal summation
What do KAR function depend on?
Location in the brain (and neto)
What are the 3 things that KARs can increase or decrease?
Glutamate release
GABA release
Cell excitability
What is the key function of Kainate receptors?
Modulation of neuronal circuits
What percent of KARs are edited at the Q/R site?
40%-50%
What is a property of the AMPAR which explains its speed?
Huge protein, basically touches postsynaptic terminal so when glutamate releases it’s “right there”
