Biology And Biomedical Sciences BIOL 2960 Lecture Notes - Lecture 5: Receptor Tyrosine Kinase, Protein Kinase A, Glycogen Phosphorylase

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salmonyak403

20 Feb 2016

School

WUSTL

Department

Biology And Biomedical Sciences

Course

Biology And Biomedical Sciences BIOL 2960

Professor

Kunkel Barbara

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Document Summary

Beta-adrenergic receptor pathway in order: adrenaline (epinephrine, beta-adrenergic receptor, g(alpha s)-gtp, adenyl cyclase, camp, protein kinase a, phosphorylase kinase, glycogen phosphorylase, glucose 1-p. Growth factor pathway: growth factor, receptor tyrosine kinase (rtk, adaptor protein, sos (cycle to convert gdp to ras-gtp), ras-gtp(active, raf (serine/threonine kinase, mek (dual-specificity kinase, map kinase (serine/threonine kinase, nuclear transcription factors, cell division. Inactive ras with gdp a: gdp-gtp exchange, active ras gtp (step 5) d, becomes inactive ras with gdp. Intrinsic gtpase activity of g-proteins (ras and trimeric g proteins) Phosphorylation of 7tm receptors and subsequent arrestin binding. camp (cgmp also) -> degraded by phosphodiesterase (pde) Viagra is an inhibitor of a specific cgmp degrading enzyme, cgmp specific pde type 5. Free energy, g, is the usable energy available in a system. The change in free energy, g, of a chemical reaction determines whether the reaction will go forward. It is equal to the difference in the free energies of the reactant and the products.

Related Questions

Select the correct order of events (1-10) for the signal transducon pathway iniated by the EGF receptor. (place the number 11 for those which are not applicable).

_____ MEK is phosphorylated by RAF.
____ The receptor undergoes a conformaonal change.
_____ The second messengers IP3 and DAG are produced.

_____ The cytoplasmic tail of the receptor is phosphorylated.

_____ An adaptor protein binds to the phosphotyrosine residues, recruing SOS and Ras.

_____ MEK is phosphorylated by ERK.

_____ RasGAP stimulates GTPase activity of Ras which returns to the GDP bound state.

_____ ERK is phosphorylated by MEK.

_____ The Galpha subunit dissociates from Gbeta/Ggamma.

_____ ERK enters the nucleus and smulates cell proliferaon.

_____ The receptor dimerizes acvang its tyrosine kinase acvity.

_____ The Galpha subunit binds to Phospholipase C.

____ Epidermal growth factor binds to the receptor.

_____ Ras is phosphorylated by RAF.
____ The Galpha protein releases GDP and binds GTP.

____Glucagon binds to the receptor.

QUESTION 1

Which of the following is an example of an extracellular signal molecule?

	a.	IP₃
	b.	cAMP
	c.	Insulin
	d.	Diacylglycerol

2 points

QUESTION 2

Nuclear hormone receptors _____

	a.	Bind to water soluble ligands
	b.	Activate second messengers
	c.	Regulate transcription in response to ligand binding
	d.	Are normally located on the plasma membrane

2 points

QUESTION 3

Which of the following does not occur when a receptor tyrosine kinase is bound by ligand?

	a.	Phosphorylation of the RTK
	b.	Cytoplasmic proteins bind the phosphorylated RTK
	c.	Dimerization of the RTK
	d.	The RTK binds to DNA to regulate transcription

2 points

QUESTION 4

Which of these is a logical signal-transduction pathway?

	a.	An intracellular receptor activates phospholipase C, which cleaves a membrane protein to form IP₃, which then activates the opening of an ER channel protein, which releases cyclic AMP into the cytoplasm, where it binds to an intracellular enzyme that carries out a response.
	b.	A G-protein-linked receptor activates G protein, which activates phospholipase C, which cleaves a membrane lipid to form IP₃, which binds to a calcium channel on the ER, which opens to release calcium ions into the cytoplasm, which bind to an intracellular enzyme that carries out a response.
	c.	An ion-channel receptor opens, allowing a steroid hormone to enter the cell; the steroid hormone then activates protein kinases that convert GTP to GDP, which binds to an intracellular enzyme that carries out a response.
	d.	A tyrosine-kinase receptor activates adenylyl cyclase, which activates phospholipase C, which converts ATP into cyclic AMP, which binds to an intracellular enzyme that carries out a response.

2 points

QUESTION 5

Which of the following is an example of signal amplification?

	a.	activation of an enzyme molecule
	b.	activation of a specific gene by a growth factor
	c.	Breakdown of many cAMP molecules
	d.	activation of 100 molecules by a single signal binding event

2 points

QUESTION 6

Consider a signal transduction pathway that utilizes cAMP as a second messenger to activate PKA (Protein Kinase A). Which of the following situations will result in the cellular response?

		The G protein releases GDP and binds to GTP
		The target protein (adenylyl cyclase) is inactive
		The regulatory subunits of PKA (Protein Kinase A) are bound to the catalytic subunits
		The appropriate G protein is bound to GDP

2 points

QUESTION 7

Which of the following is found in only some signal transduction pathways? [In other words, which is not found in all signal transduction pathways?]

		Receptor protein
		Extracellular signal molecule
		Intracellular signaling molecule
		Cellular response
		Effector protein

2 points

QUESTION 8

The enzyme that specifically catalyzes the conversion of ATP to cAMP is:

		Adenylyl phosphatase
		Adenylyl kinase
		Adenylyl dehydrogenase
		Adenylyl cyclase

2 points

QUESTION 9

If an animal cell suddenly lost the ability to produce GTP, what might happen to its signaling system?

		It would use ATP instead of GTP to activate and inactivate the G protein on the cytoplasmic side of the plasma membrane.
		It would not be able to activate and inactivate the G protein on the cytoplasmic side of the plasma membrane.
		It would employ a transduction pathway directly from an external messenger.
		It would be able to carry out reception and transduction but would not be able to respond to a signal.

2 points

QUESTION 10

A hormone signal is sent from the brain to other parts of the body via the bloodstream. Why do only certain cells respond to this signal?

		Hormones do not last long enough in the bloodstream to stimulate a cellular response
		Only cells that have a specific transcription factor gene will be able to respond to the signal
		Only cells in the immediate vicinity of the cell sending the signal will respond
		Only cells that have a receptor for the specific signal will be able to respond to it

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Biology And Biomedical Sciences BIOL 2960 Lecture Notes - Lecture 5: Receptor Tyrosine Kinase, Protein Kinase A, Glycogen Phosphorylase

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