Cell Bio - Signaling

Front 1

Endocrine Signaling

Back 1

long distance, long lasting. e.g. hormones

Front 2

Paracrine signaling

Back 2

*signaling to cells relatively close by
*result doesn't have to last as long
*e.g. ovulation

Front 3

Autocrine signaling

Back 3

cell secretes signal into extracellular space, and then binds to it
*e.g. cancer cells secrete own growth factors

Front 4

what is a big reason cancer cells grow so rapidly?

Back 4

they can secrete their own growth factors.

Front 5

Signal transduction:

Back 5

message changes form along its path

Front 6

Chemical messenger:

Back 6

something that dissolves in water and is carried across some distance to transmit a signal (SOLUBLE!!)

Front 7

ligand (primary messenger):

Back 7

something a receptor binds to, typically that comes from outside the cell

Front 8

second messenger:

Back 8

generally refers to an element in a signaling pathway that is NOT a protein (loose definition)

Front 9

what are the two typical places to find receptors?

Back 9

* on cell surface (plasma membrane)
* in the cytosol

Front 10

How would you distinguish between cytosolic and surface receptors?

Back 10

by seeing how soluble in water, i.e. how easily signal passes through membrane

Front 11

how does endo/exocytosis regulate receptors?

Back 11

regulates the number of surface receptors a cell has

Front 12

what are two ways of receptor regulation?

Back 12

*endo/exocytosis
*modification of receptor

Front 13

Give two examples of receptor modification:

Back 13

*drug tolerance
*tuning out background noise

Front 14

glycogen phosphorylase

Back 14

breaks glycogen apart and phosphorylates it

Front 15

how many molecules of glycogen phosphorylase are activated by a single epinephrine signal?

Back 15

10^6

Front 16

how many glucose released from single epinephrine molecule?

Back 16

10^8

Front 17

what is epi --> glucose an example of?

Back 17

signal amplification

Front 18

GPLR

Back 18

G Protein-Linked Receptor

Front 19

How many transmembrane domains doe a GPLR have?

Back 19

7 transmembrane domains

Front 20

What part of the GPLR interacts with the G Protein?

Back 20

The cytosolic loop between the 5th and 6th transmembrane domain

Front 21

where on the GPLR is the messenger-binding site?

Back 21

extracellular loop between the 6th and 7th transmembrane domain

Front 22

a G Protein with three subunits:

Back 22

Heterotrimeric G Protein

Front 23

What three subunits make up a heterotrimeric g protein?

Back 23

alpha, beta, gamma

Front 24

what causes the G protein to split apart and release from GPLR?

Back 24

G protein cleaves from GDP and binds to GTP

Front 25

Which two subunits never split apart?

Back 25

beta and gamma are always bound to each other

Front 26

G protein

Back 26

a signaling protein that transfers information, and it does so by binding to GTP when it's active, and cleaving to GDP to turn itself off.

Front 27

which subunit of a heterotrimeric g protein does GDP/GTP bind to?

Back 27

the alpha subunit

Front 28

adenylyl cyclase (adenylate cyclase)

Back 28

converts ATP --> Cyclic AMP (cAMP)

Front 29

what type of messenger is adenylyl cyclase?

Back 29

secondary

Front 30

what enzyme deactivates cAMP?

Back 30

phosphodiesterase

Front 31

cAMP

Back 31

Cyclic Adenine Mono-Phosphate

Front 32

PKA

Back 32

Protein Kinase A

Front 33

What role does PKA play in the liver to release glucose?

Back 33

after being activated by cAMP, PKA activates Phosphorylase Kinase, which then phosphorylates glycogen phosphorylase

Front 34

phosphorylase kinase

Back 34

*activated by PKA
*activates glycogen phosphorylase

Front 35

PKA is a generic signaling protein

Back 35

PKA can phosphorylate multiple proteins in multiple cell types

Front 36

Can PKA go into the nucleus?

Back 36

YES! e.g. activates CREB --> controlling gene transcription

Front 37

G alpha s

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G alpha stimulus

Front 38

G alpha i

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G alpha inhibitory

Front 39

why do signals enter the nucleus?

Back 39

to control gene expression

Front 40

PLC

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Phospholipase-C

Front 41

how does cholera toxin affect the cell?

Back 41

ADP-ribose binds to adenylyl cyclase, locking it in "on" position --> endless cAMP--> phosphorylates CFTR --> dehydration

Front 42

CFTR

Back 42

a Chloride pump

Front 43

what would you use to rehydrate someone with cholera?

Back 43

Gatorade!

Front 44

CRE

Back 44

cAMP Response Element

Front 45

what does PLC do?

Back 45

cleaves a phospholipid in two

Front 46

Which phospholipid does PLC cleave?

Back 46

phosphatidyl inositol

Front 47

phosphatidyl inositol

Back 47

*phospholipid with an inositol head group
*cleaved by PLC

Front 48

inositol

Back 48

a sugar which is the headgroup of phosphatidyl inositol

Front 49

why is phosphatidyl inositol always facing the cytosol

Back 49

phosphatidyl inositol has NO FLIPASE

Front 50

Which carbon of inositol is the phosphate attached to which links it to the glycerol?

Back 50

1' (one prime) carbon

Front 51

PI kinase

Back 51

phosphatidyl inositol kinase, phosphorylates phosphatidyl inositol

Front 52

likey tagets (carbons) for phosphorylation of inositol

Back 52

3', 4', and 5'

Front 53

where does PLC cleave PIP2?

Back 53

between the phosphate group and the oxygen linking it to the glycerol

Front 54

DAG

Back 54

diacylglycerol

Front 55

PIP2

Back 55

Phosphatidylinositol-4,5-bisphosphate

Front 56

IP3

Back 56

Inositol-1,4,5-trisphosphate

Front 57

how does IP3 control release of calcium?

Back 57

IP3 binds to a ligand gated calcium channel in the ER

Front 58

non-protein molecule in a signaling pathway

Back 58

second messenger e.g. IP3, PIP2, Ca+2

Front 59

PKC

Back 59

Protein Kinase C

Front 60

what happens to gap junctions if Ca is present for too long?

Back 60

the gap junctions close

Front 61

What role does Ca+2 play in the action of nitroglycerin taken for heart trouble?

Back 61

Ca+2 controls the releas of the nitric Oxide
Ca+2 + Calmodulin --> NO Synthase

Front 62

PKLR

Back 62

Protein Kinase Linked Receptor

Front 63

what are the two types of protein kinases?

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*target tyrosine
*target serine and threonine

Front 64

What do tyrosine, serine, and threonine have in common?

Back 64

They are the only 3 amino acids with an -OH on their side groups

Front 65

where is a phosphate group going to be added?

Back 65

at a hydroxy (-OH) group

Front 66

EGF

Back 66

Epidermal Growth Factor

Front 67

SH2 domain

Back 67

binds to phosphotyrosine

Front 68

what kind of protein is Ras?

Back 68

A G-Protein

Front 69

GAPs

Back 69

GTPase Activating Proteins
*deactivates Ras

Front 70

GEFs

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Guanine nucleotide Exchange Factors
Encourage GTP binding e.g. Sos

Front 71

MAPK

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Mitogen Activated Protein Kinase

Front 72

FAK

Back 72

Focal Adhesion Kinase, FAK is a tyrosine Kinase!

Front 73

TGFbeta

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Transforming Growth Factor beta

Front 74

PBD

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Protein Binding Domain (selective for active G-proteins)

Front 75

epinephrin binds to beta-adrenergic receptor

Back 75

smooth muscle relaxation, vasodilation

Front 76

epinephrine binds to alpha-receptor

Back 76

smooth muscle contraction, vasoconstriction (Galpha p)

Front 77

PLC gamma

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PLC with SH2 domain

Front 78

PLC beta

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activated by G alpha p

Front 79

3 ways to bind DNA

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*go in, direct binding to DNA
*go in, held away until activated
*go in, bind with help of another transcription factor

Front 80

transcription factor

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a protein that controls the expression of a gene

Front 81

Ets and Jun

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transcription factors that promote expression of Cyclins and Cdks

Front 82

what activates Ets and Jun?

Back 82

MAPK

Front 83

how do cdk-cyclin complexes trigger passage from G1 into S phase?

Back 83

phosphorylation of Rb

Front 84

What does Akt inhibit?

Back 84

*Apoptosis
*cell-cycle arrest

Front 85

____response element

Back 85

DNA sequence bound by/activated by ______

Front 86

What binds to Rb when it is inactive?

Back 86

E2F

Front 87

where do transcription factors bind to DNA?

Back 87

at the Promoter sequence

Front 88

what direction is RNA synthesized?

Back 88

5' --> 3'

Front 89

What direction is DNA read?

Back 89

3' --> 5'

Front 90

Where is the TATA box?

Back 90

In the core promoter sequence

Front 91

What are the GC box and the CAAT box?

Back 91

Proximal Control Elements

Front 92

Enhancer

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the name of the DNA secuence where TFs bind

Front 93

Activator

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proteins that bind to the Enhancer sequence

Front 94

mediator

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*activated/bound to by Enhacer/activator
*binds to polymerase

Front 95

Polymerase II (POL2)

Back 95

Polymerase responsible for making mRNA

Front 96

why must there be a small number of regulatory transcription factors?

Back 96

there are not enough genes for each gene to have it's own transcription factor

Front 97

How is the glucocorticoid receptor activated

Back 97

*bound by steroid hormone
*release Hsp!!!

Front 98

cDNA

Back 98

complimentary DNA

Front 99

PCR

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Polymerase Chain Reaction

Front 100

what is needed for RT-PCR

Back 100

Reverse Transcriptase

Front 101

prohormone

Back 101

a signal peptide that has not been cleaved from a protein yet

Front 102

What two things activate insulin release?

Back 102

* increased blood glucose levels
* triggered stretch receptors

Front 103

proinsulin

Back 103

*made from preproinsulin
*precursor of insulin

Front 104

catecholamines

Back 104

made by modifying the side group of tyrosine

Front 105

what is insulin's effect on the liver?

Back 105

stimulates glucose uptake

Front 106

what is insulin's effect on muscle and fat cells?

Back 106

stimulates release of more glucose transporters into the plasma membrane

Front 107

Beta pancreatic cells

Back 107

responsible for secreting insulin

Front 108

totipotent

Back 108

can give rise to an entire organism

Front 109

pluripotent

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can give rise to any of an organism's cells, but cannot form the trophoblast (placenta)

Front 110

trophoblast

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placenta

Front 111

what are the only totipotent cells?

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fertilized eggs and division up to eight cells

Front 112

SCNT

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Somatic Cell Nuclear Transfer

Front 113

FACS

Back 113

Fluorescence Activated Cell Sorter (Flow Cytometry)