chapter 11 cell communication. le 11-2 exchange of mating factors mating receptor a factor a a...
TRANSCRIPT
Chapter 11Chapter 11
Cell CommunicationCell Communication
LE 11-2Exchange ofmating factors
Mating
Receptor
a
factor
a
a factorYeast cell,mating type a
Yeast cell,mating type
a/
New a/ cell
Signal Transduction PathwaysSignal Transduction Pathways
Local signalingLocal signaling Cell junctionsCell junctions Cell-cell recognitionCell-cell recognition Local regulators – growth factorsLocal regulators – growth factors
Paracrine signalingParacrine signaling Synaptic signalingSynaptic signaling
Long-Distance signalingLong-Distance signaling Endocrine signaling - hormonesEndocrine signaling - hormones
LE 11-3a
Plasma membranes
Gap junctionsbetween animal cells
Cell junctions
Plasmodesmatabetween plant cells
LE 11-3b
Cell-cell recognition
LE 11-4a
Paracrine signaling
Local regulatordiffuses throughextracellular fluid
Secretoryvesicle
Secretingcell
Target cell
Local signaling
Electrical signalalong nerve celltriggers release ofneurotransmitter
Neurotransmitter diffuses across synapse
Synaptic signaling
Target cellis stimulated
LE 11-4b
Endocrine cell Bloodvessel
Long-distance signaling
Hormone travelsin bloodstreamto target cells
Hormonal signaling
Target cell
Three StagesThree Stages
ReceptionReception TransductionTransduction ResponseResponse
LE 11-5_1
EXTRACELLULARFLUID
Reception
Plasma membrane
Transduction
CYTOPLASM
Receptor
Signalmolecule
LE 11-5_2
EXTRACELLULARFLUID
Reception
Plasma membrane
Transduction
CYTOPLASM
Receptor
Signalmolecule
Relay molecules in a signal transductionpathway
LE 11-5_3
EXTRACELLULARFLUID
Reception
Plasma membrane
Transduction
CYTOPLASM
Receptor
Signalmolecule
Relay molecules in a signal transductionpathway
Response
Activationof cellularresponse
ReceptionReception
Receptor-Ligand interactionReceptor-Ligand interaction ReceptorsReceptors
Intracellular – testosteroneIntracellular – testosterone In plasma membrane – Figure 11.7In plasma membrane – Figure 11.7
G-protein linked receptorG-protein linked receptor Receptor tyrosine kinasesReceptor tyrosine kinases Ion channel receptors – ligand-gated ion channelIon channel receptors – ligand-gated ion channel
LE 11-6
EXTRACELLULARFLUID
Plasmamembrane
The steroidhormone testosteronepasses through theplasma membrane.
Testosterone bindsto a receptor proteinin the cytoplasm,activating it.
The hormone-receptor complexenters the nucleusand binds to specificgenes.
The bound proteinstimulates thetranscription ofthe gene into mRNA.
The mRNA istranslated into aspecific protein.
CYTOPLASM
NUCLEUS
DNA
Hormone(testosterone)
Receptorprotein
Hormone-receptorcomplex
mRNA
New protein
LE 11-7aa
Segment thatinteracts withG proteins
Signal-binding site
G-protein-linked receptor
LE 11-7ab
G-protein-linked receptor
GDP
CYTOPLASM
Plasmamembrane
G protein(inactive)
Enzyme GDP
GDPGTP
Activatedreceptor
GTP
Signal moleculeInactiveenzyme
Activatedenzyme
Cellular response
P i
LE 11-7b
Signalmolecule
Helix in themembrane
Signal-binding site
Tyr
Tyr
Tyr Tyr
Tyr
TyrTyrosines
Receptor tyrosinekinase proteins(inactive monomers)CYTOPLASM
Tyr
Tyr
Tyr Tyr
Tyr
Tyr Tyr
Tyr
Tyr Tyr
Tyr
Tyr
Tyr
Tyr
Tyr Tyr
Tyr
Tyr
Activated tyrosine-kinase regions(unphosphorylateddimer)
Signalmolecule
Dimer
Fully activated receptor tyrosine-kinase(phosphorylateddimer)
Tyr
Tyr
Tyr Tyr
Tyr
TyrPPP
PPPATP 6 ADP
Tyr
Tyr
Tyr Tyr
Tyr
TyrP
PP
PPP
Inactiverelay proteins
Cellularresponse 2
Cellularresponse 1
Activated relay proteins
6
LE 11-7c
Signalmolecule(ligand)
Gateclosed Ions
Ligand-gatedion channel receptor
Plasmamembrane
Gate closed
Gate open
Cellularresponse
TransductionTransduction
Cascades of molecular interactionsCascades of molecular interactions Signal transduction pathwaySignal transduction pathway Protein phosphorylation and Protein phosphorylation and
dephosphorylationdephosphorylation Second messengersSecond messengers Calcium ions and IPCalcium ions and IP33
LE 11-8
Signal molecule
Activated relaymolecule
Receptor
Inactiveprotein kinase
1 Activeprotein kinase
1
Inactiveprotein kinase
2 Activeprotein kinase
2
Inactiveprotein kinase
3 Activeprotein kinase
3
ADP
Inactiveprotein
Activeprotein
Cellularresponse
Phosphorylation cascade
ATP
PPP i
ADPATP
PPP i
ADPATP
PPP i
P
P
P
LE 11-9
ATP Cyclic AMP AMP
Adenylyl cyclase
PyrophosphateP P i
Phosphodiesterase
H2O
LE 11-10
cAMP
ATPSecondmessenger
First messenger(signal moleculesuch as epinephrine)
G-protein-linkedreceptor
G protein
Adenylylcyclase
Proteinkinase A
Cellular responses
GTP
LE 11-11
ATP
EXTRACELLULARFLUID
ATP
Mitochondrion
Ca2+
pump
Plasmamembrane
CYTOSOL
Endoplasmicreticulum (ER)
Ca2+
pump
Ca2+
pump
High [Ca2+]Key
Nucleus
Low [Ca2+]
LE 11-12_1
CYTOSOL
Ca2+Endoplasmicreticulum (ER)
IP3-gatedcalcium channel
IP3 (secondmessenger)
DAG
PIP2G-protein-linkedreceptor Phospholipase C
G protein
Signal molecule(first messenger)
EXTRACELLULARFLUID
GTP
LE 11-12_2
CYTOSOL
Ca2+Endoplasmicreticulum (ER)
IP3-gatedcalcium channel
IP3 (secondmessenger)
DAG
PIP2G-protein-linkedreceptor Phospholipase C
G protein
Signal molecule(first messenger)
EXTRACELLULARFLUID
GTP
Ca2+ (secondmessenger)
LE 11-12_3
CYTOSOL
Ca2+Endoplasmicreticulum (ER)
IP3-gatedcalcium channel
IP3 (secondmessenger)
DAG
PIP2G-protein-linkedreceptor Phospholipase C
G protein
Signal molecule(first messenger)
EXTRACELLULARFLUID
GTP
Ca2+ (secondmessenger)
Variousproteinsactivated
Cellularre-sponses
The ResponseThe Response
Cytoplasmic and nuclear responsesCytoplasmic and nuclear responses Fine tuningFine tuning
Signal amplificationSignal amplification SpecificitySpecificity EfficiencyEfficiency TerminationTermination
LE 11-13
Binding of epinephrine to G-protein-linked receptor (1 molecule)
Reception
Transduction
Inactive G protein
Active G protein (102 molecules)
Inactive adenylyl cyclase
Active adenylyl cyclase (102)
ATP
Cyclic AMP (104)
Inactive protein kinase A
Inactive phosphorylase kinase
Active protein kinase A (104)
Active phosphorylase kinase (105)
Active glycogen phosphorylase (106)
Inactive glycogen phosphorylase
Glycogen
Response
Glucose-1-phosphate(108 molecules)
LE 11-14
ReceptionGrowth factor
Receptor
Phosphorylationcascade
Transduction
CYTOPLASM
Inactivetranscriptionfactor
Activetranscriptionfactor
PResponse
Gene
mRNA
DNA
NUCLEUS
LE 11-15Signalmolecule
Receptor
Relaymolecules
Response 1 Response 2 Response 3
Cell B. Pathway branches,leading to two responses
Cell A. Pathway leads to a single response
Cell C. Cross-talk occursbetween two pathways
Response 4 Response 5
Activationor inhibition
Cell D. Different receptorleads to a different response
LE 11-16
Signalmolecule
Plasmamembrane
Receptor
Scaffoldingprotein
Threedifferentproteinkinases