T1Q5 Signal Transduction I & II

Question 1

RTK

Answer 1

role: receptor, growth factors

def. receptor-tyrosine kinase

Question 2

Grb2/ Sos

Answer 2

role: Guanine exchange factor for Ras
pathway: RTK

Question 3

Ras

Answer 3

role: monomeric GTPase that propogates signal to Raf/ MEK
pathway: RTK

Question 4

Raf/ MEK

Answer 4

role: effector kinase, Ras>Raf> MEK> MAP
pathway: RTK

Question 5

MAP kinase

Answer 5

def. mitogen activated protein kinase
role: conveys signals from the cytoplasm to the nucleus
pathway: RTK

Question 6

GPCR

Answer 6

def: g-protein coupled receptor
role: receptor that trigger activity of Gprotein

Question 7

Gs

Answer 7

role: First-responder, activates adenylate cyclase
* has good intrinsic GTPase activity (turns itself off)
pathway: GPCR

Question 8

Gq

Answer 8

role: first-responder
pathway: gpcr, Gq pathway

Question 9

AC

Answer 9

role: signal propagation, adenylate cyclase synthesizes cAMP
pathway: GPCR

Question 10

PLC

Answer 10

role: signal propagation, creates IP3 and diacylglyerol for Ca2+ signalling
pathway: GPCR, Gq

Question 11

cAMP

Answer 11

role: second messenger
pathway: GPCR, Gs

Question 12

DAG

Answer 12

role: second messenger, Gq pathway, triggers PKC
pathway: GPCR

Question 13

CaM Kinase

Answer 13

role: effector kinase, activated by IP3 mediated release of Ca2+
pathway: GPCR, Gq

Question 14

PKA

Answer 14

role: effector kinase, Gs pathway (targets gene regulatory proteins)
pathway: GPCR

Question 15

PKC

Answer 15

role: effector kinase, triggered by DAG produced by phospholipase C
pathway: GPCR, Gs pathway

Question 16

steroid hormones

Answer 16

synthesized from cholesterol and secreted into the blood stream

Question 17

steroid hormone receptor

Answer 17

intracellular receptors that often act as transcription factors once bound

Question 18

3 types of NOS

Answer 18

1. neurotransmitter
2. macrophages
3. endothelial cells

Question 19

mNOS/ NOS-II

Answer 19

macrophages produce NO and exploit its oxygen radical properties to kill tumor and bacteria

Question 20

NOS-I (mNOS)

Answer 20

ANS nerve terminal express a NOS and use NO as a neurotransmitter

Question 21

NOS

Answer 21

nitric oxide synthetase

converts L-arginine and NAPH to NO

Question 22

NOS-III

Answer 22

endothelial cells secrete NO due to shear stress;

the signal reaches smooth muscle and causes vasodilation through guanylyl cyclase and cGMP pathways