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Chapter 15 Cellular Signal Transduction The biochemistry and molecular biology department of CMU

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Chapter 15 Cellular Signal Transduction. The biochemistry and molecular biology department of CMU. When environment changes:. Monad ——responds directly. - PowerPoint PPT Presentation

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Page 1: Chapter 15 Cellular Signal Transduction

Chapter 15

Cellular Signal Transduction

The biochemistry and molecular biology department of CMU

Page 2: Chapter 15 Cellular Signal Transduction

When environment changes: Monad——responds directly.

Multicellular organisms——signal through elaborate system of intercellular or intracellular communication , and consequently regulate functions of organisms.

Page 3: Chapter 15 Cellular Signal Transduction

Signaling molecule

Receptor of target cell

Intracellular molecule

biological effect

Signaltransduction

Page 4: Chapter 15 Cellular Signal Transduction
Page 5: Chapter 15 Cellular Signal Transduction

§1 Signaling Molecules

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Signaling molecules

• Signaling molecules, which are released by signal-producing cells, reach and transfer biological signals to their target cells to initiate specific cellular responses.

Page 7: Chapter 15 Cellular Signal Transduction

• Extracellular molecules

• Intracellular molecules

Page 8: Chapter 15 Cellular Signal Transduction

1. Extracellular moleculesprotein & peptides: Hormone, cytokine

AA & its derivatives: Gly, Glu, adrenaline, thyroxine

Steroid: Sex Hormone, glucocorticosteroid

Fatty acid derivatives: prostaglandin

Page 9: Chapter 15 Cellular Signal Transduction

(1) Paracrine signaling (local chemical mediators)• Secreted by common cells.• Reach neighboring target cells by

passive diffusion.• Time of action is short.• Such as GF, PG

Page 10: Chapter 15 Cellular Signal Transduction

(2) Endocrine signal

• Secreted by endocrine cells.• Reach target cells by blood circulation.• Time of action is long.• Such as insulin, thyroxine, adrenalin

Page 11: Chapter 15 Cellular Signal Transduction

(3) Synaptic signal (neurotransmitters)

• Secreted by neuronal cells.• Reach another neuron by synaptic ga

p.• Time of action is short.• Such as Acetylcholine (Ach), noradren

aline

Page 12: Chapter 15 Cellular Signal Transduction

(4) Gaseous signal

• Simple structure, half life is short and active in chemistry .

• Such as NO, CO.

Page 13: Chapter 15 Cellular Signal Transduction

    

GAS MOLECULE

Page 14: Chapter 15 Cellular Signal Transduction

(5) Autocrine signal

• Act back to their own cells.• Such as GF, cytokine, interferon,

interleukin.

Page 15: Chapter 15 Cellular Signal Transduction

2. Intracellular molecule• Ca2+ ions

• DG, ceramide lipid derivatives• IP3 carbohydrate derivatives

• cAMP cGMP nucleotides

• Ras, JAK, Raf proteins

Page 16: Chapter 15 Cellular Signal Transduction

Second messenger: Small molecules synthesized in cells

in response to an external signal are the second messengers, which are responsible for intracellular signal transduction.

Such as Ca2+, DG, Cer, IP3, cAMP, cGMP

Page 17: Chapter 15 Cellular Signal Transduction

Third messengers:

Third messengers are the molecules which transmit message from outside to inside of nucleous or from inside to outside of nucleous, also called DNA binding protein.

Page 18: Chapter 15 Cellular Signal Transduction

Effect by membrane receptors

Effect by intracellular receptors

Intracellular molecules

Extracellular molecules

Signal molecules

cAMP, cGMP, IP3, DG, Ca2+

Proteins and peptides:Hormones, cytokines

Amino acid derivatives:Catecholamines

Fatty acid derivatives:Prostaglandins

Steroid hormones, Thyroxine, VD3

Page 19: Chapter 15 Cellular Signal Transduction

§2 Receptor

Page 20: Chapter 15 Cellular Signal Transduction

Receptor Receptors are specific membrane protei

ns, which are able to recognize and bind to corresponding ligand molecules, become activated, and transduce signal to next signaling molecules.

Glycoprotein or Lipoprotein

Page 21: Chapter 15 Cellular Signal Transduction

ligand   A small molecule that binds specifi

cally to a larger one; for example, a hormone is the ligand for its specific protein receptor.

Page 22: Chapter 15 Cellular Signal Transduction

• Membrane receptors

membrane

Glycoprotein

• Intracellular receptors

Cytosol or nuclei

DNA binding protein

Page 23: Chapter 15 Cellular Signal Transduction

(1) Ligand-gate ion channels type

(cyclic receptor)

ligand→receptor→ion channel open or close

1. membrane receptors

Page 24: Chapter 15 Cellular Signal Transduction
Page 25: Chapter 15 Cellular Signal Transduction
Page 26: Chapter 15 Cellular Signal Transduction
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1) 7-helices transmembrane receptor

(2) G Protein-Coupled Receptors (serpentine R)

Page 28: Chapter 15 Cellular Signal Transduction

Cytosolicside

Oligosaccharideunit

Page 29: Chapter 15 Cellular Signal Transduction

• G protein refers to any protein which binds to GDP or GTP and act as signal transduction.• G proteins consist of three different subunits (, , -subunit). • -subunit carries GTPase activity, binding and hydrolysis of GTP.

2) G protein (Guanylate binding protein)

Page 30: Chapter 15 Cellular Signal Transduction
Page 31: Chapter 15 Cellular Signal Transduction

Gs→ s→AC→cAMP↑

  Gi→ i→AC→cAMP↓

  Gq→ q →PI-PLC→IP3+DAG

  Go→ o→ion channel

Gt→ t →cGMP PDE→cGMP→ Rhodopsin

3) Classes of G protein

Page 32: Chapter 15 Cellular Signal Transduction
Page 33: Chapter 15 Cellular Signal Transduction

Glucagon

-adrenaline →s →AC↑

ACTH -adrenaline

angiotensin Ⅱacetylcholine(M2 M4)

GF release inhibitory factor

→i→AC↓

Page 34: Chapter 15 Cellular Signal Transduction

 

Page 35: Chapter 15 Cellular Signal Transduction

Ribosylation of Arg of G

G s -ATP Gs -ADP

AC

cAMP Cl- + H2O Cavity of intestinediarrheaHCO3

-

Cholera toxin

ATPase

Page 36: Chapter 15 Cellular Signal Transduction

Pertussis toxin

i -ADP-ribosylation

Gi

AC↑

allergy of histamine

cAMP ↑

Page 37: Chapter 15 Cellular Signal Transduction

AC

cGMP PDE (phosphodiesterase ) PLC

PLA2

Channel protein

4) Effect proteins of G protein

Page 38: Chapter 15 Cellular Signal Transduction

cAMP

ATP

Page 39: Chapter 15 Cellular Signal Transduction
Page 40: Chapter 15 Cellular Signal Transduction

5) Pathway of G protein linked receptor

H R G protein Es

secondary messeger

Protein kinase

Phophorylation of Es or functional protein

Biological effect

Page 41: Chapter 15 Cellular Signal Transduction

(3) Single transmembrane α-helix receptor

• Tyrosine protein kinase Receptor (catalytic receptor)

IGF - R, EGF - R

• Non tyrosine protein kinase Receptor Growth Hormone R, interferon R

Page 42: Chapter 15 Cellular Signal Transduction
Page 43: Chapter 15 Cellular Signal Transduction

Tyrosine protein kinase Receptoror receptor tyrosine kinase (RTK)

Cys-richdomain

Immunoglobulin-like

domain

EGFR IGF-1R PDGFR FGFR

Page 44: Chapter 15 Cellular Signal Transduction

Intracellularinsulin effectsCytosol

Insulin

Page 45: Chapter 15 Cellular Signal Transduction

Non-receptor tyrosine kinase (NRTK)

Page 46: Chapter 15 Cellular Signal Transduction

Domain of Downstream molecules of TPKR

SH2 domain (Scr homology 2 domain)

SH3 domain

PH domain (pleckstrin homology domain)

Page 47: Chapter 15 Cellular Signal Transduction
Page 48: Chapter 15 Cellular Signal Transduction

Membrane receptor –ANP

Soluble receptor – NO, CO

(4) Guanylate cyclase (GC) receptor

Page 49: Chapter 15 Cellular Signal Transduction
Page 50: Chapter 15 Cellular Signal Transduction

2. Intracellular receptor (transcription regulated recepto

r) Intracellular R is trans-acting

elememt cis-acting element gene expression

Localized in the cytosol and/or in the nucleus.

ligand: Steroid H, VD3, Thyroxine

Page 51: Chapter 15 Cellular Signal Transduction
Page 52: Chapter 15 Cellular Signal Transduction

3. Properties of binding of H and R

• highly specificity

• highly affinity

• saturation

• reversible binding

• special function model

Page 53: Chapter 15 Cellular Signal Transduction

4. Control of receptor activity

• Phosphorylation or dephosphorylation of R

• Phospholipid of membrane

• Enzyme catalyzed hydrolysis

• G protein regulation

Page 54: Chapter 15 Cellular Signal Transduction

(1) Recognize the special ligand

(2) Binding to special ligand

(3) Signal transduction biological effect

5. Function of receptor

Page 55: Chapter 15 Cellular Signal Transduction

§3 Pathway of Signal Transduction

Page 56: Chapter 15 Cellular Signal Transduction

Signal transduction mediated by membrane receptor

• cAMP dependent-protein kinase A pathway

• cGMP dependent PKG pathway  • Ca2+ dependent PK pathway  • Tyrosine protein Kinase pathway• NF-κB pathway  • TGF- βpathway

Page 57: Chapter 15 Cellular Signal Transduction

1. cAMP dependent-protein kinase A pathway

H R

G protein

Phosphorylation of Es or functional proteins

Biological effects

PKA

cAMPAC

Page 58: Chapter 15 Cellular Signal Transduction

(1) cAMP metabolism

ATPMg2+

PPi

cAMP

H2OMg2+ 5'-AMP

AC PDE

AC : Adenylate cyclase

PDE : Phosphodiesterase

Page 59: Chapter 15 Cellular Signal Transduction

PDE

H2O

N

N N

N

NH2

O

HOHOH

CH2

HH H

OPO

O

O

PO

O

O

P

O

O

O ATP

ACPPi

N

N N

N

NH2

O

HOHO

CH2

HH H

O

PO

O

cAMP

N

N N

N

NH2

O

HOHOH

CH2

HH H

OPO

O

O

5'-AMP

Page 60: Chapter 15 Cellular Signal Transduction

(2) Mechanism of cAMP effect

Activate cAMP-dependent protein kinase (PKA).

Page 61: Chapter 15 Cellular Signal Transduction
Page 62: Chapter 15 Cellular Signal Transduction

(3) PKA effect

Page 63: Chapter 15 Cellular Signal Transduction
Page 64: Chapter 15 Cellular Signal Transduction

Phosphorylate specifically Ser/Thr residues in several proteins

( 1 ) Regulation of metabolism

( 2 ) Regulation of gene expression

Page 65: Chapter 15 Cellular Signal Transduction

hormons: glucagon, epinephrine

inactive AC active AC

ATP cAMP

inactive PKA active PKA

phosphorylase b kinase

phosphorylase b kinaseP

ATP

ADP

H2O

Pi

phosphorylase b

P

P

ATP ADP

Pi

H2OATP ADP

glycogen synthase

glycogen synthase

P

H2OPi protein phosphatase-1

(active) (inactive)

inhibitor-1 (active)

inhibitor-1 (inactive)

phosphorylase a

ATP

Page 66: Chapter 15 Cellular Signal Transduction

CRE : cAMP response element (TGACGTCA)

CREB: CRE binding protein

Page 67: Chapter 15 Cellular Signal Transduction

DNACRE

CREBPKA

TranscriptionmRNA

CREBPKA

PCREB P

CREBP

CR

EB

CREBP

CR

EBP

CR

EB

Page 68: Chapter 15 Cellular Signal Transduction
Page 69: Chapter 15 Cellular Signal Transduction

2. Ca2+ dependent PK pathway (1) Ca2+ -DAG -dependent PKC pathway

H RPIP2

G protein PLC

IP3 DG ER

PKCCa2+ PS

Biological effects

Phosphorylation of Es or functional proteins

Page 70: Chapter 15 Cellular Signal Transduction
Page 71: Chapter 15 Cellular Signal Transduction

[Ca 2+]i 0.01-1 mol/L ( 10-7 mol/L )[Ca 2+]o 2.5mmol/L ( 10-3 mol/L ) 5000~10000×

Page 72: Chapter 15 Cellular Signal Transduction

1 ) Function of DG and IP3

IP3 + R→open of Ca2 + channel →[Ca2 + ]↑

PS, Ca2 +DG PKC ↑

Page 73: Chapter 15 Cellular Signal Transduction
Page 74: Chapter 15 Cellular Signal Transduction

2 ) Function of PKC

• regulation of metabolismPKC →Ser/Thr-P of R, enzyme,

Protein of Mb. • Gene expression  

Page 75: Chapter 15 Cellular Signal Transduction

Late response:

Trans-acting factor-P

Third messengerImmediate early genes

Third messenger-P

Activate genes

Cell proliferation

PKC

PKC

Early response:

Page 76: Chapter 15 Cellular Signal Transduction
Page 77: Chapter 15 Cellular Signal Transduction

(2) Ca2 + -CaM dependent protein kinase pathway

H R G protein PLC

IP3

Ca2+ CaM

CaMK

Biological effects

Phosphorylation of Es or functional proteins

Page 78: Chapter 15 Cellular Signal Transduction

Calmodulin (CaM ): Ca2 + binding protein

4 Ca2 + + CaM → Ca2 + - CaM

↓ CaM kinase↑

↓   Ser/Thr - P ↓

Ca2 + pump, AC ↑ GC ↑ Es (glycogen synthase, phosphorylase

kinase)

Page 79: Chapter 15 Cellular Signal Transduction
Page 80: Chapter 15 Cellular Signal Transduction
Page 81: Chapter 15 Cellular Signal Transduction

3. cGMP-dependent PKG pathway

Biological effects

Phosphorylation of Es or functional proteins

ANPNO, CO

Soluble GC

PKG

cGMPReceptor-linked GC

Page 82: Chapter 15 Cellular Signal Transduction

(1) cGMP

(2) Function of PKG Ser/Thr- P of protein and E

Mg2+

PPi H2OMg2+GTP cGMP 5'-GMP

GC PDE

GC: Guanylate cyclase

Page 83: Chapter 15 Cellular Signal Transduction

ANP ( atrial natriuretic peptides ) ↓ GC NO ↓ cGMP ↓ PKG ↓ Vascular dilatation

Page 84: Chapter 15 Cellular Signal Transduction

cis-acting elementnucleus

expression

cell memberane

phosphorylation of enzymes or proteins effects

CaM-PK

Ca2+-CaMCa2+

IP3 DGcAMP cGMP

PKA PKG PKC

ATP GTP PIP2(PC)

G AC GC G PL

peptide hormonesneurotransmitters AFP

neurotransmittershypothalamic pituitrin

Ptrans-acting factor

Page 85: Chapter 15 Cellular Signal Transduction

4. Tyrosine-protein kinase pathway (TPK)

• TPK receptor is related to proliferation, differentiation, dissociation, carcinomatous change.

• TPK :receptor TPK : Mb.non receptor TPK : cytosol

Page 86: Chapter 15 Cellular Signal Transduction

(1) Receptor TPK - Ras - MAPK pathway

• GRB2, SOS, Ras, Raf• Small G protein: Ras• MAPK (mitogen-activated protein kinas

e) :MAPK 、 MAPKK 、 MAPKKK

Page 87: Chapter 15 Cellular Signal Transduction

ÊÜÌå ÐÍTPKϸ°ûĤ

EGF, PDGF

receptor TPK Ras - GTPSOS - PGRB2 - P

Raf - P

MAPKK - P

MAPK - Ptrans-acting factor

expression

nucleus

- P

Page 88: Chapter 15 Cellular Signal Transduction

(2) JAKs - STAT pathway

ligand

non TPK receptor

JAKs STAT

gene expression

Page 89: Chapter 15 Cellular Signal Transduction

• JAKs• STAT: Signal transductors and activa

tor of transcription

Page 90: Chapter 15 Cellular Signal Transduction

ÖÊĤ

¸ÉÈÅËØÓ¦´ð Ôª¼þ

ºËĤ

»ùÒò

£ PP£

JAK

11391

84

48

113P

91P 84 P

48

113

91 84P P

P

interferons

inactive STAT

Plasma membrane

STAT complex

Nuclear membrane

geneInterferons response element

transcription

Page 91: Chapter 15 Cellular Signal Transduction
Page 92: Chapter 15 Cellular Signal Transduction
Page 93: Chapter 15 Cellular Signal Transduction

Dimerization of Receptor

Interferon

Autophosphorylation of JAK

Phosphorylation of STAT

Nuclear translocation of STAT

Interferon response element

Expression of gene

Page 94: Chapter 15 Cellular Signal Transduction

5. Nuclear factor-κB pathway

Page 95: Chapter 15 Cellular Signal Transduction

6. TGF-βpathway

Page 96: Chapter 15 Cellular Signal Transduction

Intracellular receptor (DNA transcription regulated

receptor)

• Steroid H, VD3, Thyroxine

• Cytosolic R: glycocorticosteroid H

• Nuclear R: thyroxine, estrogen, androgen, progesterone

Page 97: Chapter 15 Cellular Signal Transduction
Page 98: Chapter 15 Cellular Signal Transduction

Serum binding proteinWith bound bormone