Intracellular Signalling and the Central Dogma

Question 1

CREB is a transcription factor for genes with a ____

Answer 1

CRE

Question 2

CRE is a ____ response element

Answer 2

cAMP

Question 3

Activated CREB also recruits a co-activator called __________

Answer 3

CREB-binding protein (CBP)

Question 4

what activates transcription factors needed for immediate early genes

Answer 4

Map Kinase (Erk)

Question 5

A common pathway for growth factors is the ___________________

Answer 5

PI 3 Kinase-AKT pathway

Question 6

Activates a variety of targets, including transcription factors involved in ribosome production for increased protein synthesis

Answer 6

mTOR complex 1

Question 7

Activated receptor activates a transcription factor that travels to the nucleus to modify gene transcription

Answer 7

Model 2

Question 8

Second messenger in a signalling cascade activates a protein kinase involved in transcription regulation

Answer 8

Model 1

Question 9

is a cytosolic tyrosine kinase

Answer 9

Janus Kinase (JAK)

Question 10

JAK phosphorylates and activates transcription factors called _____

Answer 10

STAT = signal transducers and activators of transcription

• Once activated, STATS travel to the nucleus and regulate gene transcription

Question 11

JAK is activated by a cytokine ligand binding to its cell __________

Answer 11

membrane receptor

Question 12

smad is activated by:

Answer 12

by activation of receptor serine/threonine
kinases

Question 13

what are receptor serine/threonine
kinases activated by

Answer 13

Activated by TGF-beta and BMP ligands
* TGF- β = Transforming growth factor Beta
* BMP = Bone morphogenetic protein

Question 14

The specific Smad activated depends on the

Answer 14

ligand

Question 15

Once Smad is activated, it dissociates from the receptor and forms a _____ with a ______

Answer 15

complex, coSmad
This complex travels to the nucleus and associates with other translation factors and co-regulators to control transcription

Question 16

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

Answer 16

Model 3

Question 17

Intracellular receptors

Answer 17

small, hydrophobic ligands don’t need cell receptors since they easily diffuse across the plasma membrane

Ligands: Steroid hormones, thyroid hormones, retinoids, vitamin D

Question 18

where are Ligands: Steroid hormones, thyroid hormones, retinoids, and vitamin D receptors located?

Answer 18

inside the cell
- receptors are all structurally similar and are part of a nuclear receptor superfamily

Question 19

Hormone ligand binds to an intracellular receptor that, when activated directly modified transcription

Answer 19

model 4

Question 20

where is the thyroid receptor located and already bound to ____

Answer 20

the nucleus, already bound to DNA

Question 21

Binding of thyroid
hormone can ___________ transcription of genes depending on the gene itself

Answer 21

increase or decrease

Question 22

Thyroid hormone receptors commonly form ________ with other nuclear receptors

Answer 22

heterodimers

Question 23

Positively regulated genes will have _________ when thyroid hormone binds to its receptor

Answer 23

increased transcription

Question 24

Negatively regulated genes will have ____________ transcription when thyroid hormone binds to its receptor

Answer 24

decreased

Question 25

Can bind chromatin to interfere or promote transcription
- Also involved in X chromosome inactivation

Answer 25

lncRNA

Question 26

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

Answer 26

miRNA

Question 27

miRNA associates with proteins to
form an _____________

Answer 27

RNA-induced silencing complex
(RISC)

Question 28

Base-pairing of the miRNA (within
RISC) can either:

Answer 28

• Induce mRNA cleavage/destruction
• Repress translation

Question 29

The net effect is that miRNAs
within a RISC complex act to _____ mRNA post-transcription

Answer 29

silence

Question 30

____ 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

Answer 30

lncRNA