Articles Blocks 3-5

Question 1

How does acetylation affect chromatin?

Answer 1

Open, active

Question 2

How does methylation affect chromatin?

Answer 2

Depends on residue modified

Question 3

What do movers do?

Answer 3

Remodel chromatin to move nucleosomes and allow transcription

Question 4

What are the two categories of readers?

Answer 4

Chromodomain and bromodomain

Question 5

What do writers do?

Answer 5

Add modifications

Question 6

What do shapers do?

Answer 6

Mutation in histone protein itself alters function

Question 7

Exosomes vs Microvesicles (ectosomes); subcategories of microvesicles

Answer 7

Exosomes- small, arise in the endosomal system, released upon fusion with plasma membrane
Microvesicles- larger, directly bud from the plasma membrane; apoptotic bodies, large oncosomes

Question 8

What mediates clathrin-independent endocytosis?

Answer 8

Lipid rafts and caveolins

Question 9

What Extracellular Vesicles promote sperm-egg fusion?

Answer 9

CD9 carrying EVs

Question 10

Role of extracellular vesicles in retrovirus infection

Answer 10

Can carry viral proteins, receptors or RNA

Question 11

What cells do tumor derived EVs alter to establish a tumor microenvironment?How can EVs affect fibroblasts?

Answer 11

Immune cells, endothelial cells, fibroblasts, mesenchymal stem cells; convert fibroblasts in Cancer-associated fibroblasts or myofibroblasts

Question 12

What is an example of miRNA that induces cell proliferation?

Answer 12

miR-222 induces activation of PI3/AKT pathway

Question 13

How does aberrant messenger RNA cause neurodegenerative disease?

Answer 13

Long term activation of integrated stress response- phosphorylation of alpha subunit of eukaryotic translation initiation factor 2 (eIF2), mediated by PERK, GCN2, PKR, and HRI (Sensor molecules)

Question 14

What triggers sensor molecules?

Answer 14

ER stress, amino acid deprivation, viral infection, heme deprivation

Question 15

What is the outcome of the integrated stress response?

Answer 15

Increased translation of specific mRNA, decreased global mRNA translation

Question 16

Two pathways to activate NF-kappaB

Answer 16

Canonical or Alternative

Question 17

What activates canonical pathway; what is this pathway critical for?

Answer 17

Diverse factors: TNF, IL-1, LPS; immunity, inflammation, apoptosis inhibition

Question 18

What is NF-kappaB made up of in canonical pathway?

Answer 18

p50 and RelA subunits

Question 19

What inhibits NF-kappaB in canonical pathway?

Answer 19

IkBa

Question 20

What phosphorylates IkBa to allow NF-kappaB to enter cell nucleus and initiate transcription?

Answer 20

IKK (IkB kinase)

Question 21

What activates the alternative pathway? What is this pathway important for?

Answer 21

CD40, RANK, BAFF; B cell maturation, formation of secondary lymphoid organs, production of high-affinity antibodies

Question 22

What is NF-kappaB made up of in the alternative pathway?

Answer 22

p100 and RelB subunits

Question 23

What inhibits NF-kappaB in the alternative pathway? What activates NF-kappaB? How?

Answer 23

Inhibited by p100; IKKa phosphorylates P100 to convert it to p52

Question 24

What stimulates IKKa?

Answer 24

NFkB inducing kinase (NIK) phosphorylates IKKa

Question 25

How does NF-kappaB promote neoplasia?

Answer 25

Evasion of apoptosis Acquisition of limitless replicative potential Induction of angiogenesis Induction of invasion and metastasis

Question 26

NF-kappaB's role in apoptosis

Answer 26

Prosurvival and anti-apoptotic protein signaling

Question 27

NF-kappaB's role in limitless replicative potential

Answer 27

Transcription of cyclin D1

Question 28

NK-kappaB's role in angiogenesis

Answer 28

Transcription of IL-8 and VEGF (angiogenic)

Question 29

What is self renewal of stem cells?

Answer 29

Can divide without differentiation

Question 30

How is the PI3K-AKT-mTOR signaling pathway involved in cancer?

Answer 30

Constitutively activated, mediating proliferation, survival, nutrient uptake, metabolic activity, protein synthesis

Question 31

PI3K-AKT-mTOR pathway

Answer 31

GF binds RTK, activates PI3K, phosphorylates PIP2 to PIP3, PIP3 activates AKT, which stimulates mTOR (HIF activation), NFkappaB, inhibits apoptosis

Question 32

What inhibits PI3K?

Answer 32

PTEN

Question 33

What is the role of Alpha1 antitrysin?

Answer 33

Protect lung from neutrophil elastase, also antiinflammatory; in transplant recipients, increase regulatory T cells

Question 34

What secreted by adipocytes regulates energy balance?

Answer 34

Leptin

Question 35

Effect of type II diabetes in adipocytes

Answer 35

Decreased GLUT4 expression Increased RBP4, which causes increased inflammation through TLR 4 to activate inflammasome

Question 36

Hepatitis virus B protein involved in carcinoma

Answer 36

HBx

Question 37

What two factors give cryptococcus neurotropism?

Answer 37

Immune-shielding polysaccharide capsule Cell-wall immunomodulatory laccase

Question 38

Which TLRs recognize cryptococcus??

Answer 38

TLR2 and TLR9

Question 39

What molecules are important in recruitment of M1 macrophages in cryptoccus infections?

Answer 39

IFN gamma, IL6, GM-CSF, S1P

Question 40

What are two predisposing factors to cryptococcus?

Answer 40

HIV (low CD4+ T cells) Autoantibodies to GM-CSF

Question 41

Shape and structure of ebola virus (filovirus)

Answer 41

Filamentous, enveloped

Question 42

What is Magnesium's role in the cell?

Answer 42

Essential cofactor for ATP production, and many enzymatic reactions

Question 43

Shiga toxin composition and end result

Answer 43

A and B toxin, inhibits protein synthesis

Question 44

IBD is associated with what deficiency? why?

Answer 44

Vitamin D; Vit D acts as immunomodulator, antiinflammatory

Question 45

What factors are associated with increased 1,25 alpha hydroxylase production in the kidney?

Answer 45

PTH, FGF23

Question 46

What transmembrane receptor is critical for FGF23?

Answer 46

Klotho

Question 47

What is Vitamin D's role in the intestinal barrier integrity?

Answer 47

Maintains apical junctional complexes