GPCRs In vision Flashcards
SCN details
Suprachiasmatic nucleus
Group of nerve cells
Within Hypothalamus
Receives input about light from eyes
Output to pineal gland = melatonin production
Light signal pathway
Light -> eye -> optical nerve -> ganglion neurons -> more neurons -> cone/ rod cells = specialized neurons
Rods vs cones
Rods = low light
Peripheral retina
All wavelengths
Black and white
Cones = bright light
Central retina
Specific wavelengths
Red green blue
Rod structure - where does phototransduction rxn take place?
Top part
Disc compartment = filled w rho and transducin
Retinal details
Retinal is chromophore at core of rhodopsin
Absorbs a photon to transition to trans conformation
Blue light wavelength = 100% to trans
Retinal structure reminder
3-ring-11
= 3 rings - 911
= fret!!
Retinal
Memory for phototransduction pathway
Fretinal
3-ring 911
Rodeo spin = rhodopsin
Transducin = trans ducts = Pukin
Puking + drugs = empty = PDEv
No call to grandpa = cGMP goes down
Puking + drugs = empty = PDE => dehydration
Ion channels close
But you had chips, but no milk
Sodium in, but calcium down
Lack of calcium activates the great chug
= GC
= PDE inhibited
Ion channels open again
Also - rodeospin and rack of Krazy beer = RK
peeing on rodeo
= arrested = arrestin
Are PPARs nuclear hormones receptors?
Yes
Feedback Loop for nuclear hormone receptors relating to circadian Rythym
BMAL and CLOCK Regulate:
-CRY1/2 and PER1/2
-rev and ror = regulate BMAL
CRY1/2 and casein kinase regulate PER1/2
Calcium regulates casein kinase
Memory for feedback loop of circadian rhythm
BMAL = black and malicious = dark functions
PER1/2 = Perry the platypus = hero = light functions
BMAL + time limit = clock
-crying stressed victims
== Perry the platypus appears
Hostage situation also inspires reverend roar = mayor lion = to lock up BMAL
Casein kinase = cases in movement = elevator = deep fear for Perry the platypus
Testing for proper circadian rhythm
Melatonin in blood
If you see a big structure with iron in the middle
Heme
Rev erb
Vitamin D3 details
D3 binds to VDR
= Allosteric change
Now can form dimer with RXR
Binds to region of interest on DNA in nucleus
Promotes PLC transcription
IP3 production increases
DAG also released
IP3 increases calcium levels
DAG activates PKC = up calcium levels
Vitamin d3 pathway memory
D3 = on day 3
Special house guest going to talk some juicy gossip in VDR
Guest is actually guests = RXR = wrecker = two red head flirty twins
Talking about hot taken British house guest
Reminds them of Sherlock
Explain plot = transcription of PLC = pretty little cumberbatch
PLC = ingenuous person = IP3
= calcium is secret
Ingenious person has sharp mouth = dagger = DAG = PKC activation = please kill cumberbatch
Luciferase assay explained
You have promoter for luciferase enzyme gene
= nuclear receptor = engineered so that hormone in question activates this promoter
= add in luciferin
Amount of glow proportional to amount of enzyme
