Nuclear Receptors (Maize) Flashcards
3 types of receptors:
membrane
ion channel
nuclear/cytoplasmic
Nuclear receptor general mechanism of action:
modulate ____ synthesis either ____ or ____ by ____ or ____ DNA ____ for proteins
protein; directly; indirectly; inhibiting; promoting; transcription
All nuclear receptors contain 3 parts:
C-terminal, zinc fingers, N-terminal
C-terminal function?
drug (steroid) binding
Zinc fingers function?
bind to DNA (sticky fingers)
Zinc fingers have ____ ____ ____. When a steroid binds to the __-terminal, they fall off and ____ the zinc fingers (making them ____). The receptor then enters the ____ to alter activity.
heat shock proteins; C; activate; sticky; nucleus
N-terminal function?
alter DNA function
Direct action:
Drug receptor complex binds to DNA (___) to inhibit or promote ____.
RE; transcription
Direct action:
Requires ____ drug-receptor complex(es) that bind to a ____ ____.
2; response element
Indirect action:
Drug-receptor complex binds to a ____ ____, preventing it from binding to DNA. This ____ the transcription of proteins.
transcription factor; inhibits
Indirect action:
Requires ____ drug-receptor complex(es) to bind to ____ ____.
1; transcription factors
True/False. Direct and indirect mechanisms occur simultaneously.
True
What are the cytoplasmic receptors? (3)
glucocorticoid (GR1, GR2)
retinoid (RAR, RXR)
vitamin D (VDR)
GR1 binds to ____ in the kidneys, colon, salivary glands and hippocampus.
mineralocorticoids
GR2 binds to ____ in all cells and is important in ______.
glucocorticoids; anti-inflammation
Retinoic acid receptors (RAR) have subtypes:
alpha, beta, and gamma
Steroids form…
homo-dimers
GR1 & GR2
Retinoids form…
homo- and hetero-dimers (RXR, RAR)
VDRs form…
and only bind with ____ receptors
hetero-dimers
retinoid
What are the nuclear receptors? (2)
response elements
transcription factors
(the mechanism of action of these receptors all happen at the same time!)
What are the response elements (RE)? (3)
GRE - glucocorticoid
RARE - retinoic acid
TRE - transcription
What are the transcription factors? (2)
NF-kb - nuclear factor kappa B
AP1 - activator protein 1
RE+…
make anti-inflammatory proteins
GRE or RARE
RE-…
stop the production of inflammatory proteins
GRE or RARE
TRE…
cause an increase in inflammatory proteins
cytokines stimulate transcription factors AP1 and NF-kb
How does TRE play a role in the anti-inflammation process?
Typically ____ stimulate transcription factors. When you give a ____, the drug receptor complex binds to ____ ____, preventing them from reaching the ____ and therefore keeping the cell from making ____ proteins.
cytokines; steroid; transcription factors; nucleus; inflammatory
