Manifestation of Novel Social Challenges of the European Unionin the Teaching Material ofMedical Biotechnology Master’s Programmesat the University of Pécs and at the University of DebrecenIdentification number: TÁMOP-4.1.2-08/1/A-2009-0011

TYROSINE KINASE-LINKED RECEPTORS PART 1CYTOKINE-CHEMOKINE SIGNALING

Tímea Berki and Ferenc BoldizsárSignal transduction

Manifestation of Novel Social Challenges of the European Unionin the Teaching Material ofMedical Biotechnology Master’s Programmesat the University of Pécs and at the University of DebrecenIdentification number: TÁMOP-4.1.2-08/1/A-2009-0011

TÁMOP-4.1.2-08/1/A-2009-0011

Cytokine groupsStructural:1 4 a-helix bundle family• IL-2 subfamily• IFN subfamily• IL-10 subfamily2 IL-1 family3 IL-17 family

Functional: 1 Haematopoietic (EPO,

TPO, G-CSF, GM-CSF, SCF etc.)

2 Lymphocyte differentiation/activationTh1: IL-2, TNF, IFNgTh2: IL-4, IL-5, Il-13; IL-17, IL-23

3 Inflammatory (IL-1, IL-6, TNFa)

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Cytokine receptors

Interferon-a, -β, and -g receptor, IL-10 receptor

Tumor necrosis factor (TNF) receptors I and II, CD40, Fas (Apo1, CD95), CD30, CD27, nerve growth factor receptor

CCR1-10, CXCR1-5, XCR1, CX3CR1

Receptor for IL-2, IL-4, IL-7, IL-9 and IL-15 share a common chain CD132 or gc (common gamma chain). Il-2 receptor also has a third chain, a high affinity subunit IL-2Ra (CD25)

Receptors for erythropoietin, growth hormone, and IL-13

Receptor for IL-3, IL-5, and GM-CSF share a common chain,CD131 or βc (common beta chain)

Class I cytokine receptor (hematopoietin receptor

family)

Class II cytokine receptor

TNF-receptor family

Chemokine-receptor family

a β

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Characteristics of multichain cytokine receptors

gp130

LIF/OSM

IL-6

gp130

IL-11

gp130

CNTF

CNTFR

gp130

GM-CSFRa

GM-CSF

β

IL-3R

IL-3

β

IL-5R

IL-5

β

IL-2Ra

IL-2Rβ

IL-2

g

IL-2Rβ

IL-15Ra

IL-15

g

IL-7R

IL-7

g

IL-9R

IL-9

g

IL-4R

IL-4

g

GM-CSF receptor subfamily(common β subunit)

Il-6 receptor subfamily(common gp130 subunit)

Il-2 receptor subfamily(common g subunit)

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Overview of cytokine signallingCytokine receptors

consist of at least two chains, the

cytoplasmatic domains of which bind Janus

kinases (JAKs)

JAKJAK

Transcription factors (STATs) bind to the

phosphorylated receptors, and are in

turn phosphorylated by the activated JAKs

Phosphorylated STATs form dimers that

translocate into the nucleus to initiate new

gene transcription

JAKJAKPP

P P

JAKJAKPP

JAKJAK

Cytokine binding dimerizes the receptor, bringing together the

cytoplasmic JAKs, which activate each other and

phosphorylate the receptor

JAKJAKPP

PP

PP

P

P

P

P

STAT STAT

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The structure of JAK and STAT proteins

FERM yKI KI"SH2"JH7 JH6 JH5 JH4 JH3 JH2 JH1

0 200 400 600 800 1000 1200

NH2 Coiled coil DBD Lk SH2 TADYP

0 200 400 600 800

JAK structure

STAT structure

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JAK I

FERM yKI KI"SH2"JH7 JH6 JH5 JH4 JH3 JH2 JH1

0 200 400 600 800 1000 1200

KinasePseudokinaseFERM domain: band 4.1, ezrin, radixin

and moesin

JH= Janus homology domain

Proline rich membrane proximal part of

Cytokine Receptors

JAK1JAK2JAK3Tyk2

Y1038/Y1039Y1007/Y1008Y980/Y981Y1054/Y1055

Activation Y residues:

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JAK II

JAK 1 IFN-I/II, IL-2,-4,-6,-10JAK2 IFN-II, IL-3,-5, GM-CSFJAK3 IL-2g,-4,-7,-9,-15,-21TYK2 IFN-I, IL-6,-10,-12,-23

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STAT I

NH2 Coiled coil DBD Lk SH2 TADYP

0 200 400 600 800

DNA-bindingTranscriptional

activationLinker

Receptor recruitmentand dimerizationBinding of

regulatorsDimerizationDNA-binding

Nuclear transport

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Human STATs

Name Chr (Hu) MW (kDa) Function Upstream

STAT1 2q32.2 91 IFN-g/IL-12 axis (Th1 diff.)Y701 EGFR, FGFR3/4, JAK1/2, Lck, KIT, TYK2

STAT2 12q13.3 113 Y690 JAK1S727 PKCd, CamKIIg, Ribosomal protein S6 kinase alpha 5

STAT3 17q21.31 Th17

Y705 FGFR3/4, Hck, JAK1/2, cSrc, EphA3S727 ERK1/2, PKCd, MAPK8, Ribosomal protein S6 kinase alpha 5

STAT42q32.2-q32.3

Th1 S721 MAPK14, MAP2K6

STAT5A 17q11.2 Y694 JAK2, Btk

STAT5B 17q11.2Y679 cSrcY699, 725, 740, 743 EGFR

STAT6 12q13 IL-4 (Th2 diff.) JAK1/2/3

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STAT II

STAT1 IFN-I/II Inflammation

STAT2 IFN-I

STAT3 IL-6 and IL-10 families, IL-21, IL-27

STAT4 IL-12,-23 Th1, Th17

STAT5A and B IL-3,-5, GM-CSF

STAT6 IL-4,-13 Th2, allergy

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Regulation of JAK/STAT signaling• Phosphatases

SHP-1/2, CD45 – JAKSHP-2, PTP1B, TC-PTP, PTP-BL – STAT

• Nuclear export/importNES (nuclear export sequence)NLS (nuclear localization sequence)

• SOCS (suppressors of cytokine signaling) eg. PIAS (Protein Inhibitor of Activated STATs)

• Ser-phosphorylation, acetylation, o-glycosylation of TAD

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JAK inhibitors

Treatment:• Polycythemia vera, thrombocytemia, • Myeloid metaplasia, myelofibrosis• Psoriasis• RAExamples:• Lestaurtinib• Tofacitinib• Ruxolitinib

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Chemokines• 90-130 aa. polypeptidesFunctions:• Chemotaxis for different leukocytes:

– Regulation of normal leukocyte traffic– Recruitment of cells to inflammatory sites

• Enhancement of cell adhesion• Activation of effector leukocytes• Development of the inflammatory reaction• Development of normal lymphoid tissues

TÁMOP-4.1.2-08/1/A-2009-0011Chemokine signal through receptors coupled with G-proteins

Chemokine receptor Ca2+ channels

G protein

cAMP

Adenylylcyclase

Adhesion

Chemotaxis

?

Differentiation, proliferation

Ras

?

Actin polymerization

PLCβ2

DAG IP3

Ca2+PKC

Cytoskeletal rearrangment

?

GDP

gβa

GTP

a gβ

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Chemokine signaling pathways

Chemokinereceptor

Ca2+ channel

Gene expression and apoptosis

Chemokines

Ca2+

Ca2+

RAS

DAG

JNKp38Ras

pathway

gβ

GRB2

NF-B c-Jun

c-Fos

STAT5

PKC Ca2+

PYK2

Crk

CAS

GTP

a

Elk-1

MAPKpathway

PTK

Cell activation

PLA2

Rhopathway

Rho

SRF

InternalizationDegradation

Recycling

GRK

β-Arrestin

PLCβ

PKCβ

PLCg

PI3K

Akt/PKBpathway

Akt/PKB

PDK

NF-BElk-1 Elk-1

Plasma membrane

Cytoplasm

Nucleus

PIP2

IP3

GDP

gβaJAK2