Second Messenger

Question 1

G protein (cAMP)

Answer 1

alpha s of G = adenylyl cyclase = cAMP = PKA = phosphorylates proteins

Question 2

cAMP and Glycogen

Answer 2

epinephrine signals cAMP activates PKA and phosphorylates phosphorylase kinase: activates glycogen breakdown; inactivates glycogen synthase

Question 3

G proteins (IP3 and DAG)

Answer 3

ligand binds Gq = phopholipase c = PIP2 = IP3 and DAG

IP3 binds a calcium channel, lets it in
DAG bind PKC

Question 4

Calcium

Answer 4

a second messenger
[Ca] kept low to avoid signal transduction: sequestration in ER, sodium calcium exchangers

binds calmodulin

Question 5

Ras MAP

Answer 5

growth factor = dimerization = autophosphorylation = SH2 domain of GRB2 = SOS and GTP = Ras = Raf phosphorylated = MEK = MAPk = transcription factors

GAP (NF-1) binds Ras to activate hydolysis and inactivaton

Question 6

Insulin signaling

Answer 6

insulin binds tyrosine kinase = IRS1 = PI3 kinase = PIP2 = PIP3 = Akt (PKB) = GLUT4 transporters inserted, glygen synthase activated

PI3K is regulated by PTEN

Question 7

JAK STAT

Answer 7

cytokine = dimerize = bind jak = phosphorylate each other = bind STATs = stats dimerize and translocate

Question 8

Serine Threonine

Answer 8

TGFb = type II = type I = R Smad = Smad 4 - nucleus