cellular signalling and its components
- 3. Secondary Messengers Target molecule inside the cell
- 4. They greatly amplify the strength of signal, causing some changes in the activity of the cell. Components cell signaling pathways. They are short lived intracellular signalling molecules
- 6. Cyclic Nucleotides Membrane lipid derivatives Ca2+ Nitric oxide /carbon mono oxide Four classes of secondary messengers
- 8. EX. Of cAMP Action – Adrenaline, glucagon, LH
- 9. cGMP secondary messenger: 1 nitric oxide (NO) 2 the response of rods of the retina to light
- 10. PHOSPHATIDYLINOSITOL (IP) _ Phospholipid & Minor component Eukaryotic cell membrane
- 11. Phosphatidylinositol (Derived) Intracellular enzyme PHOSPHOLIPASE C (hydrolyzes) PIP2 which is found in the inner layer of plasma membrane. Hydrolysis of PIP2 yeilds two products : Diacylglycerol (DAG) Inositol-1,4,5 – triphosphate (IP3)
- 12. Diacylglycerol stimulates protien kinase C activity by greatly increasing the affinity of the enzyme for calcium ions. Protien kinase C phosphorylates specific serine and threonine residues in target protiens . Target protiens include calmodulin, the glucose transporter,cytochrome P450 etc.
- 13. This soluble molecule Diffuses through the cytosol and binds to the recptors on the endoplasmic reticulum causing release of calcium ions (ca2+ ) into the cytosol. The rise in the intracellular calcium triggers the response.
- 15. Many cells respond to extracellular stimuli by altering their intra cellular calcium concentration Ca++ secondary messenger in Two ways : • binds effector molecule ,such as enzyme , activating it. • binds intermediatory cytosolic calcium binding protien Calmodulin cause contraction of smooth muscles ACTIVATED CALMODULIN
- 16. affect nearby cells . It activates soluble guanylyl cyclase, which when activated produces another second messenger,cGMP NO Secondary messenger FREE RADICAL PLASMA MEMBRANE
- 19. Cell Signaling
- 20. CELL SIGNALING is about communication between different groups of cells and tissues. How one group of cells informs the another group of cells what to do. SIGNAL TRANSDUCTION refers to how the presence of an extracelluar signal can produce a change in the intracellular state of the cell without the initial signal crossing the membrane.
- 21. During development cells differentiate to adopt specialized roles. Cells need to know whether to live, die, or divide Neurotransmission Regulation of metabolism Contraction –expansion
- 24. AUTOCRINE signals target the cell itself PARACRINE signals target cells in the vicinity of emitting cell ENDOCRINE signals target distant cells JUXTACRINE cells target adjacent cells
- 29. CELL ADHESION
- 31. Helps stick to each other and to the surroundings CELL ADHESION MOLECULES
- 32. Cell adhesion is involved in stimulating signals that regulate
- 33. Changes in cell adhesion can be the defining event in a wide range of diseases including
- 35. CADHERIN IMMUNOGLOBULIN SUPER FAMILY CELL ADHESION MOLECULES SELECTIN INTEGRIN CELL ADHESION MOLECULES
- 36. Cell adhesion molecules Have following functions : INVOLMENT IN INFLAMMATION TUMEROGENISIS ESTBLISHMINT OF THE BLOOD –BRAIN BARRIER INVOLMENT IN LYMPHOCYTE HOMING IN REGULATION OF APOPTOSIS
- 37. CELL DEATH
- 44. CELL REGULATION
- 46. Are those which control the changes necessary for cell division They include : CYCLINS CYCLIN-DEPENDENT KINASES (CDKS) POLO-LIKE KINASES
- 48. CELL ADAPTATION
- 51. Altered cell surface receptor binding Alterations in signal for protien synthesis Synthesis of new protiens by the target cell such as heat shock protiens
- 53. (Lippincott’s Illustrated Reviews) Nalini Chandar, Susan Viselli - Cell and Molecular Biology (Lippincott’s Illustrated Reviews) -Lippincott Williams & Wilkins (2010) Bruce Alberts, Dennis Bray, Karen Hopkin, Alexander D Johnson, Julian Lewis, Martin Raff, Keith Roberts, Peter Walter-Essential Cell Biology, 4th Edition Molecular Biology of the Cell - 4th edition alberts