1 / 22

Secondary Messenger System

Secondary Messenger System. Preceptor : Dr. Manorama Swain Associate Professor Department of Biochemistry. Presenter : Aditya Agarwal 2 nd Year M.B.B.S. S.C.B. Medical College Cuttack. The Man behind it :. Nobel Prize 1971. Sir Earl Wilbur Sutherland Jr. ( 1915 – 1974 ).

tarala
Download Presentation

Secondary Messenger System

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Secondary Messenger System Preceptor : Dr. Manorama Swain Associate Professor Department of Biochemistry Presenter : AdityaAgarwal 2nd Year M.B.B.S. S.C.B. Medical College Cuttack

  2. The Man behind it : Nobel Prize 1971 Sir Earl Wilbur Sutherland Jr. ( 1915 – 1974 )

  3. Contents 1 2 Signal Transmission What are Second Messengers ? Why Secondary Messenger Systems ? Usage of S.M. Systems 3 4 5 Different S.M. Systems

  4. What are Second Messengers ? • They are small, intra-cellular molecules that transmit signals • from a receptor to a target. • They are short-lived. • They can have multiple downstream targets, thereby expanding the scope of • signal transmission. [Signal Amplification] • Their concentration inside the cell is in accordance with the biochemical • message sent by the ligand bound to receptor.

  5. Signal Transmission Reception G-protein Transduction Effector Enzyme Induction

  6. WHY Secondary Messenger System ? Steroidal Non-Steroidal Cascade Mechanism Direct Gene Activation Signal Transduction Slower, Long-term Faster, Short-term

  7. Usage of Second Messengers Note : Not only do Multiple Hormones utilize the same SM system, but a single hormone can activate more than one SM system too.

  8. Cyclic AMP System

  9. Cyclic AMP System Activation of G-Protein

  10. Cyclic AMP System ATP Synthesis PPi Adenylyl Cyclase cAMP H2O Breakdown cAMP Phosphodiesterase H+ AMP

  11. Cyclic AMP System Protein Kinase A (inactive) Protein Kinase A (active) CREB - cAMP Response Element Binding Protein Cytoplasmic Nuclear TRANSCRIPTION Activates CREB (Transcription Factor) which binds to cAMP Response Element (DNA Sequences) Phosphorylation of other enzymes

  12. Cyclic AMP System Functions of Protein Kinase A : Stimulates Glycogenolysis & Gluconeogenesis Sequesters Ca2+ into Sarcoplasmic Reticulum Activates Reward System in CNS Vasodilation for Smooth Muscles Did you know ? CAFFEINE & THEOPHYLLINE inhibit cAMP PDE

  13. Cyclic GMP System

  14. Cyclic GMP System Functions of Protein Kinase G : Vasodilation i.e., Increased Blood Flow Regulates Na+ Ion Channel Conductance Photo-transduction in the Eye Penile Erection Did you know ? SILDENAFIL inhibits PDE 5

  15. IP3 and DAG System

  16. IP3 and DAG System Functions of Protein Kinase C Vasoconstriction Smooth Muscle Contraction in GIT & RT Platelet aggregation Ejaculation Did you know ? CYCLOSPORINE (Immuno-suppressive) blocks this pathway !

  17. Receptor Tyrosine Kinase

  18. Tyrosine Kinase System Ligand JAK-STAT Pathway Receptor-mediated Endocytosis Receptor Tyrosine Kinase Ligand-Receptor Complex Phosphorylation of Transcription Factors Phosphorylation of cytosolic Tyrosine Kinase Phosphorylation of other enzymes Physiological Effects Gene Transcription & Translation

  19. Tyrosine Kinase System HERCEPTIN used for Breast Cancer. IMATINIB Mesylate in the treatment of CML. When Growth factors receptors remains in “ON” state, then the cell undergoes uncontrolled mitosis (CANCER)… DEFITINIB used for Lung Cancer. SUNITINIB used for GIST.

  20. Summary • What are Second Messengers • Different SM Systems • Functions of Protein Kinases • Principles behind usage of Coffee, Tea, Viagra, • Immuno-suppressives and Anti-Cancer Drugs Take Home/Hostel Message Now that Mechanism of Action of various Protein Kinase Receptors been delineated, a lot of research is being done on Drugs blocking these receptors. Shift in treatment from Radiotherapy to Chemotherapy because of high specificity of Tyrosine Kinase inhibitors (TKI).

  21. Bibliography • Dr. Manorama Swain • Lehninger’s Principles of Biochemistry • Guyton’s Textbook of Physiology • http://en.wikipedia.org • http://www.britannica.com • http://www.ncbi.nlm.nih.gov • (USA National Library of Medicine)

  22. Thank You

More Related