Manifestation of Novel Social Challenges of the European Union

in the Teaching Material of

Medical Biotechnology Master’s Programmes

at the University of Pécs and at the University of Debrecen Identification number: TÁMOP-4.1.2-08/1/A-2009-0011

ENZYME-LINKED

RECEPTORS

Tímea Berki and Ferenc Boldizsár

Signal transduction

Manifestation of Novel Social Challenges of the European Union

in the Teaching Material of

Medical Biotechnology Master’s Programmes

at the University of Pécs and at the University of Debrecen Identification number: TÁMOP-4.1.2-08/1/A-2009-0011

TÁMOP-4.1.2-08/1/A-2009-0011

Receptors with enzyme activity

• Receptor Tyrosine Kinases (RTK)

– e.g. PDGF, insulin, EGF, VEGF and FGF receptors

• Receptor Tyrosine Phosphatases

– e.g. CD45 (cluster determinant-45) protein of T cells and

macrophages

• Receptor Guanylate Cyclases

– e.g. natriuretic peptide receptors

• Receptor Serine/Threonine Kinases

– e.g. activin and TGF-β receptors

• Tyrosine-Kinase Associated Receptors: receptors that

associate with proteins that have tyrosine kinase activity

(Cytokine Receptors)

TÁMOP-4.1.2-08/1/A-2009-0011

Receptor classes I

Class Examples Structural Features of Class

I EGF receptor, NEU/HER2, HER3 Cysteine-rich sequences

II Insulin receptor, IGF-1 receptor Cysteine-rich sequences; characterized by disulfide-linked heterotetramers

III PDGF receptors, c-Kit Contain 5 immunoglobulin-like domains; contain the kinase insert

IV FGF receptors Contain 3 immunoglobulin-like domains as well as the kinase insert; acidic domain

V Vascular endothelial cell growth factor (VEGF) receptor

Contain 7 immunoglobulin-like domains as well as the kinase Insert domain

VI Hepatocyte growth factor (HGF) and scatter factor (SF) receptors

Heterodimeric like the class II receptors except that one of the two protein subunits is completely extracellular. The HGF receptor is a proto-oncogene that was originally identified as the MET oncogene

VII Neurotrophin receptor family (TRKA, TRKB, TRKC) and NGF receptor

Contain no or few cysteine-rich domains; NGFR has leucine rich domain

TÁMOP-4.1.2-08/1/A-2009-0011

Receptor classes II

Ligand Receptors Ligand Traps Accessory Receptors Smads

TGF-b TbR-II TbR-I ALK5

Latency-associated polypeptide (LAP) Decorin a2-macroglobulin

Betaglycan Smad2 Smad3 Smad4

Inhibin ActR-IIB ALK4

Betaglycan Smad2 Smad3 Smad4

Activin ActR-IIB ALK4

Follistatin Smad2 Smad3 Smad4

Nodal GDF1 Vg1

ActR-IIB ALK4 ALK7

DAN Cerberus

Cripto Smad2 Smad3 Smad4

BMP2 BMP4 BMP7

BMPR-II ALK3 ALK6

DAN Cerberus Chordin/SOG Follistatin Noggin

Smad1 Smad5 Smad8 Smad4

BMP4 GDF5

ActR-IIB ALK3 ALK6

Chordin/SOG Follistatin Noggin

Smad1 Smad5 Smad8 Smad4

BMP7 ActR-IIB ALK2

Chordin/SOG Follistatin Noggin

Smad1 Smad5 Smad8 Smad4

MIS

AMHR-II ALK2 ALK3 ALK6

Smad1 Smad5 Smad8 Smad4

TGF-b TbR-II ALK1

Endoglin

Smad1 Smad5 Smad8 Smad4

TÁMOP-4.1.2-08/1/A-2009-0011

Introduction

“Complete” receptor tyrosine kinase “Incomplete” receptor

Cytoplasmic

non-receptor

tyrosine kinase

Adaptor

Signal Signal

TÁMOP-4.1.2-08/1/A-2009-0011

Receptor tyrosine kinase (RTK)

families

• 90 unique Tyr kinases in the human genome, 58 are RTKs

• Growth factor, cytokine and hormone receptors

• Classes:

I EGFR family (ErbB) X LTK family

II Insulin rec. family XI TIE family

III PDGF family XII ROR family

IV FGF family XIII DDR family

V VEGF family XIV RET family

VI HGF family (c-Met) XV KLG family

VII Trk family XVI RYK family

VIII Eph family XVII MuSK family

IX AXL family

TÁMOP-4.1.2-08/1/A-2009-0011

Fibronectin III

Leucine-rich

Cysteine-rich

Acid-box

Kinase

IG-like

VEGFR1

VEGFR2

VEGFR3

PDGFR

PDGFRβ

CSF1R

Kit

Kit2

Ryk Torso EGFR

ErbB2

ErbB3

ErbB4

Met

Ron

Sea

TrkA

TrkB

TrkC

INSR

IGF1R

IRR

Axl

Mer

Sky

Eph

Eck

Eek

Erk

Elk

Ehk1

Ehk2

Sek

Hek

Hek11

Cek-9

Myk-1

Myk-2

Ros FGFR1

FGFR2

FGFR3

FGFR4

Tie

Tie2

DDR Ret Torpedo Ror1

Ror2

Ltk

Alk

EGF-like

Cadherin

Factor VIII-like

Glicyne-rich Kringle

C1r-like

Receptor tyrosine kinase family

TÁMOP-4.1.2-08/1/A-2009-0011

Main steps of RTK activation

1 Ligand binding

2 Dimerization

3 Autophosphorylation

4 Signal complex (adapter proteins, kinases

etc.)

TÁMOP-4.1.2-08/1/A-2009-0011

Dimerization of GF receptors

Plasma membrane

Cytoplasm

Juxtamembrane region C-terminal region Activation and catalytic loop (substrate precluding)

Activation and catalytic loop (substrate accessible)

P

P

P

P

P

P

P

P

P P

ATP ATP

Dimerization

TÁMOP-4.1.2-08/1/A-2009-0011

Autophosphorylation of RTKs

p120 Ras-Gap

PLCg

Phosphotyrosine Y559

Y581

Y716

Y741

Y751

Y771

Y1009

Y1021

Phosphotyrosine Y992

Y1045

Y1068

Y1086

Y1148

Y1173

PDGFR

P

P

P

P

P

P

P

P

P

P

P

P

P

P

EGFR

P

P

P

P

P

P

P

P

P

P

Shc SLP7

6

Abl

Cbl PI3K

IRS-1

GRB2 SRC SHP-

1

STAT1

Crk

Nck

TÁMOP-4.1.2-08/1/A-2009-0011

Members of the initial signal complex

• Enzymes/transcription factors:

Src/Syk family kinases, SHP-1, PLCg, Sos,

Vav, RasGAP, STAT1 etc.

• Adaptors/regulators:

Grb2, SLP-76, SOCS1, Nck, Shc, Crk-L, p85

etc.

• Adaptors/docking proteins:

FRS2, IRS1, DOK1 etc.

TÁMOP-4.1.2-08/1/A-2009-0011

Members of the signaling complex

SRC

PLCg

PKC

PI3K RAS

RAF

MEK

MAPKs

Plasma membrane

SOS SHC GRB2

RSK

FAK

Differentiation

Transcriptional regulation

Differentiation/Growth

Nucleus

Y

Y

Y

Y

Y

Y

Growth factor/Hormone

Receptor PTK

Cytoplasm

TÁMOP-4.1.2-08/1/A-2009-0011

Ras-MAPK pathway

Elk-1 P

P

Plasma membrane

Cytoplasm RAS

SOS

GRB2

Growth factor/Hormone

Receptor PTK

Active

RAS RAF

MEK1

ERK2

Adaptor

Guanine

nucleotide

exchange

factor

(GEF)

GDP GTP

P

P

MEK1 P

P

ERK2 P

P

ERK2 P

P ERK2

P

P

SRE

Elk-1

Elk-1 P

P

SRF

Nucleus

AP-1

P

P cFos

+

?

Gene transcription

TÁMOP-4.1.2-08/1/A-2009-0011

Parallel MAPK pathways

ERK pathway p38 pathway JNK pathway

Mitogens Stress/Cytokines Ligands and

activators

A-raf, B-raf, C-raf MEKK1, DLK, MLK2, ASK,

TAK1, TAO, TAO2 MAPKKK

MEK1, MEK2 MEK3, MEK6 MEK4, MEK7 MAPKK

ERK1, ERK2, ERK5 ERK3, ERK4 p38a, b, d JNK1, 2, 3 MAPK

RSK1

RSK2

RSK3

RSK4

MSK1

MSK2

MNK1

MNK2

MK2

MK3

MK5B

MK

PDK1

TÁMOP-4.1.2-08/1/A-2009-0011

MAPK-activated kinases (MKs)

• RSK (ribosomal S6 kinases)

cytoplasmic (initiation factors of translation, apoptosis

machinery, oestrogen rec., Sos), phosphorylated form can

translocate to nucleus (ATF4, c-Fos, SRF)

• MSK (mitogen- and stress-activated kinases )

in nucleus (CREB, histone H3, HMGN1, ATF1)

• MNK (MAPK-interacting kinases)

translation initiation complex

TÁMOP-4.1.2-08/1/A-2009-0011

Turning-off the pathway

• Phosphatases PTP1B, SHP1/2, DEP1

• Phosphorylation of GEF (Sos) decreases the

affinity to the adapter (Grb2)

• Removal of cell surface receptors by

endocytosis

TÁMOP-4.1.2-08/1/A-2009-0011

MAPK/ERK in growth and

differentation

Ca2+

FoxO3 ER

Stat1/1

CREB TIF1A

C-Myc/ N-Myc Pax6

Elk-1

C-Fos

Ets

UBF

ETV1

HMGN1

ATF1

Histone H3

SRF

TIF1A ETV1

ERa C-Fos

Myt1 ATF4

MITF Nur77

Mad1

C/EBPβ

Ran BP3

Erk1/2 MSK1/2 BUB1 p90RSK P27

KIP1

Erk1

MEK1

PKC

Erk1/2

MNK1/2

MEK1/2

B-Raf c-Raf

c-Raf PKA

PAK

Src

PI3K Fyn FAK

Tpl2/ Cot1

C-TAK1

MPK-1/2

cdc25

MPK-3

PP1/ PP2At

SOS

Bim

C3G

SOS SOS Ras

Rac

Rap1 PLCg

cPLA2

P14

MP1

IMP

PEA-15

PPARg

Spred

KSR

14-3-3

Shc FRS2 IRS

GRB2 Pax

CAS Tal

elF4B

rpS6

Filamin A

IkBa

CRK

TSC2 eEF2

Kinase DAPK

BAD

GSK-3

METTL1 nNos

Ca2+

GRB2

PYK2

B-Raf

PD98059

U0126

Late endosome

Cell adhesion

Transiation

control

Ion channels,

receptors

Heterodimer

Cytoskeletal

proteins

Progression

of cell cycle Nucleus

Cytoplasm

Ca2+

Ion channels

RTKs

RTKs

Integrins

Spry

cAMP

p90RSK