Signalling In Disease Flashcards
(44 cards)
Which 2 factors cause loss of control
Genetics eg mutations
Disease eg cholera or pertussis
Are all gpcr in all cells
No which causes either localised or systemic effects
How do gpcr change overtime
Levels of exp change during development
What are orphan receptors
Receptors that are close to structure as other gpcr but don’t have an identified ligand
Which 2 things cause hyperthyroidism
Overproduction of tsh/thyrotropin
Or failure of tsh gpcr to inactivate
What is the diabetes called which has lack of response /lack of ligand arginine vasopressin / ADH
Nephrogenic diabetes insipidus
What 3 things are in nephrogenic insipidus
Under production of ADH
Inability for receptor to recognise ligand
Inability for receptor to activate G protein to activate adenylyl cyclase
Where do ligands bind on gpcr
Exo loops or n terminal
What part of a gpcr binds with a G protein
Cytoloops and c terminus
What is bound to rhodopsin gpcr
11 CIS Retinal
What G protein associates which rhodopsin
Transducin
What happens to retinal and receptor when light hits
Converts 11 CIs to all trans retinal
And conformational change in receptor
What is the importance of activation of G protein transducin in rhodopsin
Activates pde converting cgmp to 5’gmp
This blocks the na cation channel and hyperpolarisation cell = activated neurone
What determines wavelength of light perceived by rhodopsin
Where retinal binds on the 7 tm domain on the lysine residue
The aa sequence surrounding it
How many aa determines diff between red and green wavelength perceived by rhodopsin
3 aa around the 7 tmd lysine where retinal binds
Why is red green colour blindness often in males
X linked and they need only 1
Why can recomb of red and green receptor genes occur
They are nearly homologous except 3 aa
Explain the 2 types of recomb occurring
Recomb where there’s unequal recomb and one x has more red copies and no green copies etc
Recombination within genes to form hybrids of red and green gene in one
What G protein mutation causes night blindness
G a transducin (can’t activate pde)
What g alpha subunit causes defects in blood clotting
G alpha 12
What is caused by a mutation in a B3 subunit
Hypertension
What mutation causes adrenal cortical tumours
Ai2
What syndrome is caused by mutation in the g alpha s subunit (activates pka)
Mccune Albright syndrome
What 2 diseases cause modification in g subunits
Cholera vibrio cholera - gas subunit
Pertussis bordatella whooping cough - gai subunit (inhibitory)
