Vorlesung: Molekulare Mechanismen der Signaltransduktion
Werbung
Vorlesung: Molekulare Mechanismen der Signaltransduktion Lehrbuch der Molekularen Zellbiologie, m. CD-ROM von Bruce Alberts, Dennis Bray, Karen Hopkin Molecular Cell Biology von Harvey Lodish, Arnold Berk, Paul Matsudaira 908 Seiten - Wiley-VCH Erscheinungsdatum: April 2005 ISBN: 3527311602 Preis: EUR 69,00 Sprache: Englisch Gebundene Ausgabe - 1052 Seiten - W H Freeman Erscheinungsdatum: 18. September 2003 Auflage: 5th ISBN: 0716743663 Preis: EUR 75,50 Molecular Biology of the Cell von Bruce Alberts, Dennis Bray, Julian Lewis Sprache: Englisch Broschiert - 1616 Seiten - Garland Science Erscheinungsdatum: 30. März 2002 SBN: 0815340729 Preis: EUR 82,50 Molekulare Zellbiologie von Gerald Karp 1026 Seiten - Springer, Berlin Erscheinungsdatum: März 2005 ISBN: 3540238573 Preis: EUR 59,95 Literatur Biochemie der Regulation und Signaltransduktion von Gerhard Krauss 522 Seiten - Wiley-VCH Verlag Erscheinungsdatum: Juli 1997 ISBN: 3527293930 Preis: 79,00€ (deutsch) Immunobiology, w. CD-ROM von Charles A. Janeway , Paul Travers ,Mark Walport 528 Seiten - Wiley-VCH Erscheinungsdatum: 17. Juli 2001 Auflage: 2. Aufl. ISBN: 3527303782 Preis: 89,00€ (englisch) Signal Transduction von Bastien Gomperts Sprache: Englisch Broschiert - 848 Seiten - Churchill Livingstone Erscheinungsdatum: Juli 2004 ISBN: 0443073104 EUR 62,00 424 Seiten - Academic Press Erscheinungsdatum: 1. März 2002 ISBN: 0122896319 Preis: 74.o5€ General Principles in Signal Transduction Signals Receptors Mediator(s) Effector(s) Response -Kinases -Phospholipases -GTPases -Adaptors -Transcription Factors -Structural Proteins -Enzymes -Proliferation -Differentiation -Apoptosis -Cell activation General Principles in Signal Transduction General Principles in Signal Transduction General Principles in Signal Transduction General Principles in Signal Transduction General Principles in Signal Transduction General Principles in Signal Transduction General Principles in Signal Transduction Signals Receptors Hydrophobic Signals Hydrophilic Signals Mediator(s) Intracellular Receptors Response General Principles in Signal Transduction Steroid Receptor Family • Cytoplasmic transcription factors • Bind lipophilic ligands – Estrogen, progesterone, testosterone – Vitamin D Steroid sex hormones – Glucocorticoids and mineralocorticoids – Thyroid hormone (nuclear receptor) Steroid Receptor Signaling Steroid Receptor Signaling Steroid Receptor Structure General Principles in Signal Transduction General Principles in Signal Transduction A B D C Different classes of cell surface receptors O. Modlich 29.11. J. Bode 8./15.11. nächste Woche W. Schulz 20.12. Two main apoptosis signaling pathways F. Essmann (22.11.) Death ligand Death receptor FADD cytokines Bad TCR Bim p53 Puma Noxa Pro-Caspase-8 Bcl-2 Bcl-xLL Bid Caspase-8 (active) Bax Bak mitochondrium Caspase-9 Omi/HtrA2 AIF Smac/Diablo Cyt c Apaf-1 IAP cytoplasm Caspase-3 (executioner caspases) DFF/CAD Death Substrates Caspase-independent Death DNA Fragmentation nucleus General Principles in Signal Transduction Signals Hydrophilic Signals Receptors Mediator(s) Response General Principles in Signal Transduction -Kinases -Phospholipases -Second messengers -GTPases -Adaptors Biochemical Reactions in Signal Transduction Kinases -protein kinases phosphorylate their substrates -phosphorylation changes the activity, subcellular location, or aggregation of the proteins Biochemical Reactions in Signal Transduction Kinases Nucleophiler Angriff Energiegefälle: Kein Rückreaktion ! Biochemical Reactions in Signal Transduction Kinases Primary structure of a kinase Kinase domain ( approx. 30 kDa) Subdomains I II III IV V AXK VI VII VIII IX X XI Activation loop (T-loop) Tyr Kinases: Src, EGF-R, PDGF-R, JAK Ser/Thr Kinases: PKC, Raf, MAPK, Akt Dual-specificity kinases: MEK, MKK Lipid Kinase: PI3K General Principles in Signal Transduction -Kinases -Phospholipases -Second messengers -GTPases -Adaptors Biochemical Reactions in Signal Transduction Phospholipases -phospholipase C (PLC) catabolizes phospholipids (PIP2) generating IP3 -IP3 binds a receptor and increases cytosolic calcium -increased cytosolic calcium activates other signaling mechanisms General Principles in Signal Transduction -Kinases -Phospholipases -Second messengers -GTPases -Adaptors Second Messengers • Cyclic nucleotides – Cyclic AMP and cyclic GMP • Lipid metabolites – Diacylglycerol – Inositol triphosphate • Calcium Calcium Calcium concentrations extracellular: 1-2 mM cytosolic: 50 - 100 nM intracellular lumenal (ER etc.): 30 - 300 µM transient calcium influx into the cytosol Clinical Application: Immunosuppression by FK506 and Cyclosporin A (Calcium-Sensor) (Phosphatase) (Transkriptionsfaktor) Genexpression General Principles in Signal Transduction -Kinases -Phospholipases -Second messengers -GTPases -Adaptors General Principles in Signal Transduction GTP-binding proteins in signal transduction a) G-Proteins (heterotrimeric GTPases) 29.11. b) monomeric GTPases = small GTPases = ras-like GTPases Biochemical Reactions in Signal Transduction GTPases GEFs GAPs Signal -G proteins are turned “on” and “off” by GTP and GDP, respectively - active G proteins transmit the signal to other “downstream” proteins Biochemical Reactions in Signal Transduction GTPases GTPases: Ras, Rac1, Rho, Cdc42 GEFs: Sos, Ras-GRP, Vav1 Vav1 General Principles in Signal Transduction -Kinases -Phospholipases -Second messengers -GTPases -Adaptors Biochemical Reactions in Signal Transduction Adaptor proteins Example: SH2 domains -recognize phosphoryated tyrosines -Recruit signaling proteins to receptor -adaptors have no enzymatic activity of their own -function is to recruit signaling enzymes to the receptor-ligand complex -this concentrates signaling proteins and increases efficiency Biochemical Reactions in Signal Transduction SH2 Adaptor Proteins • • • Example: SH2 domains -recognize phosphoryated tyrosines -Recruit signaling proteins to receptor Many proteins have a domain called SH2 Portion that recognizes phosphotyrosine Interacts with phosphotyrosine (like a ligand and receptor) xxxxxYxxxx P xxxxxYxxxx Biochemical Reactions in Signal Transduction Adaptor proteins Protein-protein interaction domains SH2 14-3-3 SH3 P -Y-X-X-hyPTB -P-X-X-P-X- R-S-X-S-X-P WW PH P -hy-X-N-P-X-Y- P -P-P-X-Y- PIP3 Biochemical Reactions in Signal Transduction Adaptor proteins Cytoplasmic adaptor proteins MW (kD) Interaction partners Expression Grb2 28 Sos,LAT,c-Cbl,Shc,SLP-76, Vav,SHP-2,WASP,HPK1 ubiquitous Grap 28 Sos,LAT,Shc,SAM68 B-Cells, T-Cells Name Structure PxxP Gads Nck-1 47 PxxP Shb PxxP Shc PxxP 40 PxxP SH2-Binding Site SH3-Binding Site 55,66 46,52,66 SH3-Domain T-Cells, NK Cells Mast cells. Macrophages, Thrombocytes Sos,SLP-76,WASP,PAK,Cbl ubiquitous LAT,Shc,SLP-76,HPK1 Grb2,LAT,PI3K,Eps8, PLCγ1,CD3ζ,Src Grb2,SHIP,ZAP-70,CD3ζ, Igα/β,RasGAP PTB-Domain ubiquitous ubiquitous SH2-Domain Biochemical Reactions in Signal Transduction Adaptor proteins Transmembrane adaptor proteins Name Structure MW (kD) Interaction partners Expression 36-38 Grb2,Gads,SLP-76, PLCγ1/2,c-Cbl,PI3K T-Cells, NK Cells, Mast cells, Platelets 75-85 Csk,Fyn Ubiquitous SIT 30-40 SHP2 B-Cells, T-Cells TRIM 29-30 PI3K T-Cells, NK Cells LAT PAG/Cbp PxxP PxxP TM PxxP SH2-Binding Site SH3-Binding Site A. Leo and B.Schraven, Current Opinion in Immunology, 2001 Next week: Signaling from receptor tyrosine kinases Stimulates Mitogen Activated Protein kinases (MAPK)