The Synapse 1

Question 1

What is the diameter and thickness of the postsynaptic density?

Answer 1

300-500nm diameter

50-60 nm thick

Question 2

Functions of the PSD?

Answer 2

Scaffold and regulate receptors

Question 3

PSD-95 is a protein within the PSD.

Describe its domains N-C terminus

Answer 3

N Terminus (which can dimerise with another psd95 N terminus)
PDZ domains 1-2-3
SH3 domain (allows protein protein interactions)
Guanylate kinase like domain (GUK) which has no enzymes activity

Question 4

nNOS binds to what pdz domain of psd-95?

Answer 4

2

Question 5

Presynaptic neuroligin bind to what?

Answer 5

Pdz 3 and Beta neurexin on presynaptic terminal

Question 6

How many amino acids in length is a PDZ domain

Answer 6

About 100

Question 7

What does the pdz domain bind to?

Answer 7

The C terminus of some protein which have the sequence

X-thr/ser-X-val-COOH

Question 8

What sequence of amino acids is repeated in pdz domains and why is this important?

Answer 8

GLGF

creates hydrophobic pocket for hydrophobic C terminals

Question 9

Why is arginine important in pdz domains?

Answer 9

Arginine at position 318 interacts with COO- via a water molecule

Question 10

What technique was used to find where NMDAR bind to on psd95?

Answer 10

Yeast two hybrid

Question 11

Who did the experiment to discover where NMDARs bind to in psd-95?

Answer 11

Kornau et al 1995

Question 12

What was the bait in the yeast two hybrid experiment by kornau et al 1995?

Answer 12

C terminal of NMDAR

Question 13

What was the prey in the yeast two experiment by kornau et al 1995?

Answer 13

Varying psd-95 constructs

Question 14

What are the bait and prey attached to? Why is this important?

Answer 14

Bait - DNA binding domain
Prey - transcriptional activating domain

Come together is complementary bait and prey to allow transcription of something which allows yeast to survive

Question 15

What NMDAR subunit binds to psd-95? And where in psd-95 does it bind?

Answer 15

GluN2B
Pdz 2

However 2A and 2B bind to pdz 1 and 2 by 2B has high affinity for pdz-2

Question 16

What does GRIP an abbreviation for?

Answer 16

Glutamate Receptor Interacting Protein

Question 17

What does PICK1 an abbreviation for?

Answer 17

Protein Interacting with C-kinase 1

Question 18

What ionotropic glutamate receptor binds to GRIP and PICK1?

Answer 18

AMPARs

Question 19

PICK1 binds with which subunits of AMPARs?

Answer 19

GluA2 and GluA3

Question 20

What did Xi et al show in regards to PICK1 and GluA2 and 3 subunits?

Answer 20

They are colocalised via immunohistochemistry

Question 21

What is the motif on AMPARs which allows them to interact with pdz domains?

Answer 21

SVKI C terminal (on GluA2 and GluA3)

Shares homologous with xT/SxV motif

Question 22

What pdz domains of grip do AMPARs bind to?

Answer 22

Pdz 4 and 5

They also co immunoprecipitate

Question 23

What phosphorylates GluA2 subunits to regulate scaffolding binding?

Answer 23

PKC

Question 24

Where does PKC phosphorylate GluA2 subunits? What does this achieve?

Answer 24

S880
Promotes binding to PICK1 over GRIP
this is linked to internalisation and LTD

Question 25

What does TARPS stand for? give an example

Answer 25

Transmembrane AMPA receptor regulatory protein | Stargazin

Question 26

Stargazin is similar to what other protein?

Answer 26

Gamma subunit for voltage gated calcium channels

Question 27

Stargazin interacts with what ionotropic glutamate receptor?

Answer 27

AMPA | site of interaction unknown

Question 28

Functions of stargazin

Answer 28

Permits indirect associate of AMPARs with psd-95 AMPA surface delivery Anchoring Lateral translocation

Question 29

What type of experiments show stargazin interacts with psd-95?

Answer 29

Co-immunoprecipitation | Immunohistochemistry shows punctate fluorescent blobs when coexpressed

Question 30

What particular subunit has been studied for the role of stargazin in ampa surface delivery?

Answer 30

GluR1 Deleting the terminal 4 amino acids of stargazin reduces mEPSPs at post synaptic membrane as it cannot bind to psd-95 Therefore, although psd-95 is not important for number of AMPARs at membrane it is important for post synaptic membrane localisation

Question 31

What does mGluR receptors scaffold to?

Answer 31

Homer

Question 32

What group discovered the association of mGluR5 and Homer? | What technique was used?

Answer 32

Brakeman et al 1997 | Yeast two hybrid and coimmunopreciptation with antihomer antibody then stain for mGluR5

Question 33

What domain of homer binds to mGluR?

Answer 33

EVH1 domain bind to the c terminus if mGluR | EVH1 is in someways similar to pdz and contains GLGF repeats and an upstream arginine

Question 34

What does an increase in synaptic activity do it homer

Answer 34

It increases its expression

Question 35

What are the 2 domains of homer from C-N terminus?

Answer 35

C terminus - coiled coil + leucine zipper - EVH1 - N terminus

Question 36

What is the function of the coiled coil and leucine zipper domain on homer?

Answer 36

Allows for homomeric and hetromeric interactions between homer isoforms