Cell communication Chapter 9 Genes and Development

Cell communication

Chapter 9Genes and Development

Fig. 9.1

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

CytoplasmExternal environment

Membrane receptor

Intracellular receptor

Plasma membrane

Signaltransduction

pathway

Signaltransduction

pathway

Cellularresponse

Cellularresponse

Hydrophobicligand

Hydrophilicligand

Fig. 9.2a


a.

Direct Contact

Adjacentplasmamembrane

Plasmamembrane


Plasmamembrane

Fig. 9.2b


b.

Paracrine Signaling

Secretory cell

Adjacenttarget cells

Fig. 9.2c


c.

Endocrine Signaling

Blood vessel

Distant target cells

Hormone secretion intoblood by endocrine gland

Fig. 9.2d


d.

Synaptic Signaling

Nerve cellNeurotransmitter

Synaptic gap

Target cell

Fig. 9.2


a. b. c. d.

Synaptic SignalingEndocrine SignalingParacrine Signaling

Nerve cellNeurotransmitter

Synaptic gap

Target cell

Blood vessel

Distant target cells

Secretory cell

Direct Contact


Plasmamembrane

Adjacenttarget cells

Hormone secretion intoblood by endocrine gland


Plasmamembrane

Fig. 9.3Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Kinase

Phosphatase

Kinase

Phosphatase

O

P

O–

O O–

O

P

O–

O O–

OH

OHTyr

ADP

Pi

ADP

ATP

ATP

Seror

Thr

Seror

Thr

Tyr

Pi

Fig. 9.4a


a.

Ions

Ions

Ligand(signal)

Fig. 9.4b


b.

Ligand (signal)

Inactive

ActiveCellular

response

Fig. 9.4c


c.

gb

g

a a

a

b

GDP GTP GTP

Ions

G protein EnzymeIon channel

GPCR

G protein activateseither enzyme or ion channel

Ligand(signal)

b g

a

bg

a

a

Fig. 9.4


a.

c.

b.

Ions

Ions

Ligand (signal)

Inactive

Active

gb

g

a a

a

b

GDP GTP GTP

Ions

G protein EnzymeIon channel

GPCR

G protein activateseither enzyme or ion channel

Ligand(signal)

Cellularresponse

Ligand(signal)

b g

a

bg

a

a

Fig. 9.5


Hormone

Inhibitor

Inhibitor

1. Hormones cross plasma membrane and bind to cytoplasmic receptors.

2. Hormone binding alters receptor conformation so it no longer binds inhibitor.

5. Cellular response is a change in gene expression.

3. Hormone–receptor complex translocates to nucleus.

4. Hormone–receptor complex binds to DNA. This usually turns on transcription, but can also turn it off.

Signal molecule-binding domain

DNA-bindingsite exposed

DNA-bindingsite blocked

Transcription-activating domainGenetranscription

Fig. 9.6


Ligands

Phosphorylated proteinIntracellular kinase domain

Extracellular ligand-binding domain

P

P

P

P

P

P

P

P P

P

P

P

PP

P

P

P

P

Phosphategroups

Transmembrane RTK proteins

1. Ligand binds to the receptor.

2. Two receptors associate (dimerize) and phosphorylate each other (autophosphorylation).

3. Response proteins bind to phospho- tyrosine on receptor. Receptor can phosphorylate other response proteins.

Dimerization andautophosphorylation

Cellularresponse


Glycogen

Glycogen synthase

Glycogen

synthase

Insulin receptor

Disulfide bridge

Insulin

Glucose

aa

bb

P P

PP

P

1. Insulin binds to the extracellular domain of the a-subunit of the insulin receptor.

2. The b-subunit of one insulin receptor phosphorylates the other, allowing the insulin response proteins to be activated.

3. Phosphorylated insulin response proteins activate glycogen synthase.

4. Glycogen synthase converts glucose into glycogen.

Insulinresponseprotein

Glycogen synthase

Insulin

a a

b b

Fig. 9.8aCopyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Response

Signal

Receptor

Activator

ActiveInactive

Inactive

Inactive

Active

Active

MKKMKK

MKMK

MKKKMKKK

a.

Ras

PP

P

PP

P

MAP kinase cascade

Firstkinase

Secondkinase

MAPkinase

Responseproteins

Cellularresponse

Responseproteins

Responseproteins

MKKK

MKK

MK

MKKK

MKK

MK

Fig. 9.10


Ras

GT

1. Proteins bound to receptor activate Ras by exchanging GDP for GTP.

2. Ras activates the first kinase (Raf)

3. Raf activates the second kinase (MEK)

4. MEK activates MA P kinases (ERK) 5. MAP kinase (ERK) activates

proteins to produce cellular responses, including transcription factors that alter gene expression

Activatestranscriptionfactors

NuclearmembraneCellular

response

Activatestranscriptionfactors

GDP

Ras

Raf

Raf

MEK

P

PP

P

P

P

P

P

P

P

PP P

P

PResponse

proteinResponse

protein

Responseprotein

Responseprotein

Responseprotein

Responseprotein

P

MEK

ERK

ERK

Fig. 9.11


GPCR

Ligand

GPCR

ab g

a

b g b g

a

GDPInactive G

protein GTP

GDP

Cellularresponse

Effector protein

GTPGTP

gb

a ab g b g

a

Active Gprotein

Pi

Fig. 9.12


P

–O

–O O

O

P

–O –O

O

O

P O CH2

O

O

a.

b.

Extracellular space

Cytoplasm

Phospholipase C

PIP2

O

C

O C

O

C C

OC

O

P

O

O–O

P

O

O O–

O–

P

O–

O O–

OOH OHOH

DAG + IP3

O

C

O C

O

C C

OC

OH

P

O

O

OO–

P

O

O O–

O–

P

O–

O O–

OOH OHOH

P

–O

O O

OO

CH2

DAG

IP3

P

O–

–O O

O

P

O–

O–

OPP i

cAMP

Adenylyl cyclase

NH2

N

NH2

N

ATP cAMP + PPi

Plasmamembrane

Cleaved byphospholipase C


Ligand

GPCR

GDP GTP

ATP

Activates PKA

Cellularresponse

Responseprotein

Responseprotein

Adenylyl cyclase

Cytoplasm

Nucleus Nucleus

cAMP

b g

a

b gb g

a

b g

Fig. 9.15 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Ca2+

ER

Cytoplasm

Phospholipase CGPCR

DAG

PIP

IP3

b g b ga

Cellularresponse

Ca2+

bindingprotein

gb ga

b

Ligand

GDP GTP

Fig. 9.16


Ca2+

Calmodulin

Calmodulin

a. b.

Activeprotein

Inactiveprotein

Ca2+ Ca2+

Ca2+

Ca2+

Fig. 9.17 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

P

Cytoplasm

Epinephrine

Glucagon

P P P

P P P P

Glycogen

CH2

GDP

GDP

GPCR

PKA

cAMP

Glucose-6-phosphate

Adenylylcyclase

Adenylylcyclase

Phosphorylasekinase

Glycogenphosphorylase

GTPGTP

P

ATPATP

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Cell communication Chapter 9 Genes and Development