week 6

Question 1

Why can lipidated proteins be considered “peripheral” membrane proteins?

Answer 1

A lipase can release the protein to the cytoplasm or extracellular space

Question 2

what are examples of a Signal (Ligand)

Answer 2

Chemical, Light, Gravity, Sound, Electric field, Temperature

Question 3

Chemical =

Molecular signals =

Answer 3

ligand

Question 4

what does a receptor do?

Answer 4

senses a signal

Question 5

what occurs when a receptor senses a signal?

Answer 5

A physical change occurs (typically protein conformation)

Question 6

what is Transduction?

Answer 6

Signal is relayed through the cell usually via secondary messengers

Question 7

what is an Effector?

Answer 7

target of signaling ( may be several in signaling pathway)

Question 8

what is the Target?

Answer 8

Cellular response, Result of transduction

-May be a physiological change or change in gene expression

Question 9

Cellular signals are usually_____

Answer 9

molecular

Question 10

Signals can be from ___ or ____

Answer 10

environmental or cellular sources

Question 11

Proteins, hormones, growth factors

Molecular signals are all

Answer 11

cellular signals

Question 12

Environmental signals can be ____ or ____

Answer 12

molecular or physical

Question 13

The females of many insects (like Gypsy moths) release a pheromone molecule that males can sense at very low concentrations. One method of controlling such insects is to spray a pheromone disrupter that mimics the pheromone. Such a disrupter, would be considered a_____________.

Answer 13

ligand

Question 14

GPCR and Tyrosine Kinase are

Answer 14

Receptors

Question 15

Binding of ligand to receptor is

Answer 15

specific and based on shape

Question 16

Conformational change results in __

Answer 16

transmission of extracellular signal to intracellular signal

Question 17

Which regions appears to be most altered upon binding ATP?

Answer 17

Blue

Question 18

*What major structures are typically involved in conformational changes?

Answer 18

Disruption of R-group bonds result in different structural motif interactions

Question 19

What are the G-protien subunits?

Answer 19

G alpha, G beta, G y

Question 20

This releases G beta and G y

Answer 20

activated G alpha

Question 21

G beta and G y

Answer 21

Act as signaling molecules

Question 22

GPCRs are

Answer 22

Integral membrane proteins

Question 23

what is the structure of a GPCR?

Answer 23

Extracellular ligand-binding domain

Intracellular G-protein coupled domain

Question 24

when is GDP is bound to the G alpha

Answer 24

The G protein is off

Question 25

when is GTP is bound to the G alpha

Answer 25

The G protein in on

Question 26

what triggers binding of GTP to G alpha?

Answer 26

Conformation change of GPCR

Question 27

The G-proteins we have discussed are also known as “large G-proteins” or “heteromeric G-proteins”. They associate with membranes through_____________.

Answer 27

interactions with GPCR | lipidation

Question 28

The peptide sequence motifs in Worksheet 8 are an example of ______________ protein structure.

Answer 28

primary

Question 29

Receptor Tyrosine Kinase (RTK)

Answer 29

Integral membrane protein that are monomer in the inactive state (unbound)

Question 30

What happens when a ligand binds to a RTK

Answer 30

- Monomers dimerize - Tyrosine kinase domain of protein is activated and phosphorylates tyrosines - Other signaling proteins can be activated

Question 31

What does Dimerize mean?

Answer 31

monomer + monomer = Dimer

Question 32

Act as message relays

Answer 32

Second messengers

Question 33

cAMP and IP3 are two common examples

Answer 33

Second messengers

Question 34

cAMP

Answer 34

Usually associated with GPCR pathways

Question 35

adenylyl cylcase

Answer 35

An enzyme stimulated by G alpha after ligand binding (to make cAMP)

Question 36

what is used to make cAMP

Answer 36

ATP

Question 37

What does cAMP target after activation

Answer 37

cAMP targets proteins - protein kinase A (PKA)

Question 38

Phosphoinostiol System

Answer 38

- PLC (activated through G protein) cleaves the carbon chains of a phospholipid (PIP2) - Results in IP3 ( lets Ca enter cytoplasm) and DAG (stays with membrane)

Question 39

What function do (protein) kinases complete?

Answer 39

Add a phosphate to proteins

Question 40

Kinases can be activated through

Answer 40

phosphorylation

Question 41

Phosphatases

Answer 41

removing phosphate

Question 42

signal amplification

Answer 42

A result from Kinase cascade activity

Question 43

Many pathways use kinases to transmit information. | If a phosphatase that opposing the action of a critical kinase were to be inhibited then ___________.

Answer 43

the signal transmission would be enhanced

Question 44

Avastin is a drug that is used in chemotherapy to stop the growth of cancer cells. It acts by inhibiting certain kinases. A cancer cell might acquire resistance to this drug by ____________.

Answer 44

decreasing the activity of phosphatases

Question 45

Target proteins

Answer 45

carry out the response to a signal

Question 46

target proteins can...

Answer 46

Can alter gene expression Can alter existing proteins to cause a change Can directly regulate cell growth by altering cell cycle or metabolism

Question 47

If a ligand was present and enzyme at the A arrow was blocked, what would you predict? (ws9)

Answer 47

Kinase activity would remain the same and | PLA2 activity would remain the same

Question 48

cPLA2 is directly activated by several insect venoms. If the enzyme at the B arrow were blocked during a bee sting, what would you predict? ( ws9)

Answer 48

Prostaglandin levels would rise and | COX activity would increase

Question 49

If GTP was blocked from associating with the molecule indicated by arrow A, then __________________. 9

Answer 49

kinase activity would remain the same

Question 50

If cellular PIP2 levels were decreased, then _________________.9

Answer 50

cytosolic calcium levels would remain the same?

Question 51

Inhibiting the step noted by the arrow “A” would _____________.10

Answer 51

cause TAZ to build up in the cytoplasm

Question 52

Inhibiting the step indicated by | arrow B, would__________.

Answer 52

cause cell density to increase

Question 53

Hippo was first described by Drosophila geneticists. In the Drosophila field, new mutants are named after their phenotype. Why do you think these flies look like Hippos? 10

Answer 53

They are bloated with too many cells.

Question 54

Activation of the membrane-associated ER caused cell growth and proliferation in ____tissue

Answer 54

Breast

Question 55

Although this figure shows estrogen as the ligand, researchers used EDC. Why?

Answer 55

EDC only binds the membrane-bound receptors

Question 56

What is the role of eNOS?

Answer 56

To produce nitric oxide

Question 57

Activation membrane-bound ER caused vascular protective responses.

Answer 57

True