From Signal Transduction From Signal Transduction to Targeted Therapy to Targeted Therapy
(Fall 2010)(Fall 2010)
Pin Ling ( 凌 斌 ), Ph.D.
Department of Microbiology & Immunology, NCKU
ext 5632
Outline Signaling Transduction
- Definition- History- Mechanisms- Example
Targeted Therapy - Mechanisms
- Examples- Current Trend
Your involvement is the key to success in this lecture.
What is Signaling Transduction?What is Signaling Transduction?
• Conversion of a signal from one physical or chemical form into another.
• The process initiated by recognition a Signal by a Sensor (receptor, kinase or enzyme) in the cell, then converting to one or more cellular responses through a series of signal
transmission.
ReceptorsReceptors
Signal Signal TransduceTransduce
rsrs
EffectorsEffectors
A simple scheme of signal A simple scheme of signal transductiontransduction
Fig 15-1 Adopted from Molecular Biology of The Cell
Q: Who first gets the idea about “ Signal Transduction”?Molecules involved in this
process, called Signaling Molecules
History of signaling transductionHistory of signaling transduction
Adopted from Nobelprize.org
Rodbell’s findings
Adopted from Nobelprize.org
Gilman’s findings
Adopted from Nobelprize.org
Adopted from Molecular Cell Biology
Current view of GPCR signalingCurrent view of GPCR signaling
A simple scheme of signal transduction
Fig 15-1 Adopted from Molecular Biology of The Cell
Receptors
Signal Transducers
Effectors
Four types of surface receptorsFour types of surface receptors
Adopted from Molecular Cell Biology
GPCR
Ion Channel
Receptor w/o Enzyme
Receptor w/ Enzyme
Adopted from Molecular Cell Biology
Four common second messengersFour common second messengers
cAMP is the first 2cAMP is the first 2ndnd Messenger Messenger
Adopted from Nobelprize.org
(1st messenger)(2nd messenger)
A simple scheme of signal transduction
Fig 15-1 Adopted from Molecular Biology of The Cell
Receptors
Signal Transduce
rs
Effectors
Two types of signal transducers
Enzymatic proteins: Kinase, GTPase,….etc
Non-Enzymatic proteins: Adaptors, Scaffolds,...etc
Post-Translation Modifications (PTMs): Phosphorylation…..
Protein-Protein Interactions,Signalsome Formation
Two major biochemical events in signal transduction
Examples of enzymatic Examples of enzymatic proteinsproteins
Adopted from Molecular Cell Biology
Adaptors in signal Adaptors in signal transductiontransduction
Adopted from Molecular Cell Biology
Ras activation following EGFR signaling
Adopted from Molecular Cell Biology
Ras activates the MAPK/ERK pathway
Adopted from Cell Signaling
A simple scheme of signal transduction
Fig 15-1 Adopted from Molecular Biology of The Cell
Receptors
Signal Transducers
Effectors
Types of Post-Translation Modifications
PhosphorylationMethylationAcetylation
UbiquitinationSumoylation
Chemical groups
Small peptides
PalmitoylationMyristoylation Lipid groups
Glycosylation Sugar groups
Features of Post-Translation Modifications
1. Most are Reversible
2. Regulate Protein Activity, Protein Localization, Protein Interaction,……etc.
3. Focus on “Protein Phosphorylation” today
Protein Protein PhosphorylationPhosphorylation
Adopted from Nobelprize.org
Activation of a enzyme by phosphorylation
Mechanism of Phosphorylation by cAPK (PKA)
Adopted from Molecular Cell Biology
G. Manning et al., Science. 2002, 298:1912-34.
Human Kinome
1. 518 protein kinases
2. Tyr & Ser/Thr kinases
3. Involve many processes
4. Dysregulation => diseases
5. Targets for therapy
(Charles Swyers, Nature 2004)
Examples of kinase-associated diseases
Post-translational modifications of human nucleosomal histones
Modular interaction domains Modular interaction domains in in
signaling transductionsignaling transduction
(Pawson et al, Science 2003)
Check more details in BIND database(Biomolecular Interaction Network Database)www.bind.ca
Cell. 2004 Jan 23;116(2):191-203.
Specificity in signal transduction: from phosphotyrosine-SH2 domain interactions to complex cellular systems.
Pawson TonySamuel Lunenfeld Research Institute, Mt. Sinai Hospital, 600 University Avenue, Toronto, ON M5G 1X5, Canada. [email protected]
Science 18 April 2003: Vol. 300. no. 5618, pp. 445 – 452
Assembly of Cell Regulatory Systems Through Protein Interaction Domains
Tony Pawson1,2* and Piers Nash1
1 Samuel Lunenfeld Research Institute, Mount Sinai Hospital, 600 University Avenue, Toronto, Ontario M5G 1X5, Canada.2 Department of Medical Genetics and Microbiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada. * To whom correspondence should be addressed. E-mail: [email protected]
Signaling Signaling SpecificitySpecificity
Multiple signaling cascades form signaling networks
Cell. 2000 Oct 13;103(2):193-200.
Curr Opin Cell Biol. 2002 Apr;14(2):173-9.M. Synder et al,
Approaches to studying signaling networks
Trends in TherapiesTrends in Therapies
1. Gene Therapy – genetic diseases, cancer,…etc
2. Cell Therapy – degenerative diseases (Alzheimer, Myocardial disorders….etc)
3. Targeted Therapy – cancer, immune disorders,…etc
=> Each has its pros and cons.
Signaling Transduction => Molecular Targets Signaling Transduction => Molecular Targets => Targeted Therapy=> Targeted Therapy
Fig 15-1 Adopted from Molecular Biology of The Cell
Receptors
Signal Transducers
Effectors
Dysregulation of signaling Dysregulation of signaling molecules leads to disordersmolecules leads to disorders
A simple scheme of signal A simple scheme of signal transductiontransduction
Q1: How to do targeted therapy?Q1: How to do targeted therapy?
Two major biochemical events in signal transduction:
(1) Post-Translation Modifications: protein phosphorylation
(2) Protein-Protein Interactions: ligand- receptor, protein-dimeriztion
Molecules designed to block these two biochemical events
Abl, BCR-Abl, & Abl, BCR-Abl, & Chronic Myelogenous Leukemia (CML)Chronic Myelogenous Leukemia (CML)
Nat Rev Cancer. 2005 Mar;5(3):172-83.
Nat Rev Cancer. 2005 Mar;5(3):172-83.
Leukemogenic signaling of BCR-Abl
Development of Chronic Myelogenous Leukemia
(CML)
Nat Rev Cancer. 2005 Mar;5(3):172-83.
Copyright ©2001 AlphaMed Press
Mauro, M. J. et al. Oncologist 2001;6:233-238
Figure 1. Schematic representation of the mechanism of action of STI571
Gleevec (STI 571, Imatinib): A Small Molecule with a Big Impact
Q2: How to deal with drug resistance ?Q2: How to deal with drug resistance ?
Some CML patients develop resistance or relapse
to targeting small molecule (Imatinib).
(1) Develop modified drug (2nd generation kinase
inhibitor)
(2) Combination therapy
2nd generation TKI -Imatinib-like compound
J. Cortes et al Blood, 2009
IC 50, lower is better.
Molecules for targeted therapies
(1)Small molecules: target the ATP binding site or other regions in protein kinase domain, e.g. Gleevec (to BCR-Abl)
(2) Monoclonal Abs: target receptors, cytokines, other surface proteins,
e.g. Herceptin (to Her), Erbitux (to EGFR)
(3) Others: Decoy receptors (soluble CTLA4-Ig), Vaccines, RNAi,..etc
Targeting drugs in clinical trialsTargeting drugs in clinical trials
Ab-mediated signaling inhibitionAb-mediated signaling inhibition
Adopted from Nature Biotechnology 23, 1147 - 1157 (2005)
Approved mAbApproved mAbCancer Cancer
therapeuticstherapeutics
SummarSummaryy1. Signaling transduction is essential for cells to
communicate with environmental stimuli.
2. It usually includes three major components: Receptor, Transducer, & Effector.
3. Two key biochemical events during signaling transduction: PTMs & Protein Interactions
4. Dysregulation of signaling molecules perturbs cellular processes then leading to disease develpoment.
5. Targeted therapy are mostly based on targeting two biochemical events.
Kinase: www.kinase.com (seq, evolution & kinomes)
Protein kinase resource: www.kinasenet.org (kinase structure)
Alliance for cell signaling: www.signaling-gateway.org
Phosphosite database: www.phosphosite.org (in vivo phosphorylation sites)
Websites for signaling Websites for signaling transductiontransduction
HomeworHomeworkk
Gleevec has also been found to effectively treat other
cancer cells such as gastrointestinal stromal tumors
(GIST). However, scientists found no mutation of Abl
kinase in these tumor cells. Please explain the
underlying mechanism of how Gleevec is still working
in this kind of cancer cells even without c-Abl mutation.
B. Druker , Cancer Cell, 2002
22ndnd generation TKI generation TKI STI 571-like compoundSTI 571-like compound
Kantarjian et al. Nature Reviews Drug Discovery 5, 717–718 (September 2006) | doi:10.1038/nrd2135