Intracellular Signalling and the Central Dogma Flashcards
CREB is a transcription factor for genes with a ____
CRE
CRE is a ____ response element
cAMP
Activated CREB also recruits a co-activator called __________
CREB-binding protein (CBP)
what activates transcription factors needed for immediate early genes
Map Kinase (Erk)
A common pathway for growth factors is the ___________________
PI 3 Kinase-AKT pathway
Activates a variety of targets, including transcription factors involved in ribosome production for increased protein synthesis
mTOR complex 1
Activated receptor activates a transcription factor that travels to the nucleus to modify gene transcription
Model 2
Second messenger in a signalling cascade activates a protein kinase involved in transcription regulation
Model 1
is a cytosolic tyrosine kinase
Janus Kinase (JAK)
JAK phosphorylates and activates transcription factors called _____
STAT = signal transducers and activators of transcription
- Once activated, STATS travel to the nucleus and regulate gene transcription
JAK is activated by a cytokine ligand binding to its cell __________
membrane receptor
smad is activated by:
by activation of receptor serine/threonine
kinases
what are receptor serine/threonine
kinases activated by
Activated by TGF-beta and BMP ligands
* TGF- β = Transforming growth factor Beta
* BMP = Bone morphogenetic protein
The specific Smad activated depends on the
ligand
Once Smad is activated, it dissociates from the receptor and forms a _____ with a ______
complex, coSmad
This complex travels to the nucleus and associates with other translation factors and co-regulators to control transcription
Activation of a receptor triggers destruction of an inhibitory protein of a transcription factor. The transcription factor can the travel to the nucleus to modify gene transcription
Model 3
Intracellular receptors
small, hydrophobic ligands don’t need cell receptors since they easily diffuse across the plasma membrane
Ligands: Steroid hormones, thyroid hormones, retinoids, vitamin D
where are Ligands: Steroid hormones, thyroid hormones, retinoids, and vitamin D receptors located?
inside the cell
- receptors are all structurally similar and are part of a nuclear receptor superfamily
Hormone ligand binds to an intracellular receptor that, when activated directly modified transcription
model 4
where is the thyroid receptor located and already bound to ____
the nucleus, already bound to DNA
Binding of thyroid
hormone can ___________ transcription of genes depending on the gene itself
increase or decrease
Thyroid hormone receptors commonly form ________ with other nuclear receptors
heterodimers
Positively regulated genes will have _________ when thyroid hormone binds to its receptor
increased transcription
Negatively regulated genes will have ____________ transcription when thyroid hormone binds to its receptor
decreased
Can bind chromatin to interfere or promote transcription
- Also involved in X chromosome inactivation
lncRNA
Post-transcriptional silencing of gene expression by ______ is a fundamental mechanism of gene regulation present in all eukaryotes. Each _____ can modulate activity of multiple protein-coding
genes
miRNA
miRNA associates with proteins to
form an _____________
RNA-induced silencing complex
(RISC)
Base-pairing of the miRNA (within
RISC) can either:
- Induce mRNA cleavage/destruction
- Repress translation
The net effect is that miRNAs
within a RISC complex act to _____ mRNA post-transcription
silence
____ can function is many ways to modify
transcription by:
A) promote gene transcription
B) supress gene transcription
C) Promote chromatin modification directly
D) Stabilize protein complexes that modify chromatin structure
lncRNA
