Shared Flashcard Set

Details

Steroid Nuclear Receptors
EXAM 2
28
Medical
Professional
09/02/2010

Additional Medical Flashcards

 


 

Cards

Term
what is retinoic acid synthesized from?
Definition
Vitamin A
Term
the nuclear receptor superfamily has structural domains for what
Definition
ligand binding, DNA binding, and trascriptional activation
Term
what inactivates the GC receptor
Definition
Hsp90
Term
What happens when GC binds to its receptor?
Definition
it displaces Hsp90 and translocates to the nucleus where it coactivated on the DNA by HAT
Term
when the ligand binds to the receptor what happens to the complex?
Definition
there is a conformational change and the Hsp is released, causing the DNA binding site on the recetpor to be exposed
Term
what is the function of the SHBG?
Definition
increases the half life of the steroids in the extracellular space prior to entry
Term
why does the primary response to steroid hormones NOT involve signal amplification?
Definition
It does not use enzymes
Term
In ligand independent DNA binding, where is the receptor?
Definition
bound to DNA even in absence of ligand, but with a corepressor on it
Term
How does gene transcription occur in ligand independent DNA binding?
Definition
the ligand binds to the receptor already placed on the DNA
Term
what is the effect of non traditional steroid receptor DNA binding
Definition
the binding of a hormone to different RE's to facilitate selective receptor modulation of gene transcription, in response to binding by different ligands with various agonistic and antagonistic activities.
Term
what does non-traditional steroid receptor DNA binding and Transcription involve?
Definition
ligand dependent interaction with the steroid receptor
Term
Non-traditional steroid receptors is classeified by what?
Definition
binding to DNA at sites other than SRE's
Term
what is the function of SERM?
Definition
create unique conformational change in the receptor to target specific co-factor binding and alteration of gene transcription.
Term
what does idoxifene interaction with the E2 receptor
Definition
exposes regions of the receptor that allows it to bind to ERE
Term
what is Raloxefine's effect on Estrogen receptors?
Definition
it does NOT exposes receptor to binding of ERE. It instead exposes the ER receptor to the RRE
Term
how is NO synthesized?
Definition
from arginine (via no synthase)
Term
what is the effect of Nitroglycerin
Definition
It is converted to NO, which increases blood flow to the heart
Term
what is the pathway of NO activating to guanylyl Cyclase
Definition
Ach->Calmodulin->NO->guanylyl cyclase
Term
what two things do cGmP activate
Definition
PKG and PDE
Term
What effect does atrial natriuretic peptide have on guanylyl cyclase?
Definition
It activates this enzyme
Term
what is the effect of light activation on PDE and GMP signaling?
Definition
it activates transducin, which activates phosphodiesterase leading to deactivation of cyclic GMP
Term
what are examples of eicosanoids?
Definition
prostaglandins, prostacyclin, thromboxanes, and leukotrienes
Term
how are eicosanoids synthesized?
Definition
through arachidonic acid (made by PLA2)
Term
arachidonic acid is converted to prostaglandin by what enzyme?
Definition
cyclooxygenase
Term
what is COX1's function
Definition
release of normal prostaglandins
Term
what is COX2's function
Definition
production of more prostaglandins due to inflammation
Term
Prostaglandin secretion happens by
Definition
excitatory neurotransmitter Glutamate
Term
what is the signalling pathway for Prostaglandins
Definition
adenylyl cyclase
Supporting users have an ad free experience!