Biosignalling
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The document discusses bio signaling, emphasizing the importance of cellular responses to external signals through various signal transducing systems. It outlines features such as specificity, cooperativity, amplification, integration, and desensitization, while detailing different types of signal transducing systems including gated ion channels and receptor enzymes. Additionally, it touches on G protein signaling and the role of guanosine nucleotide binding proteins.
Biosignalling
- 3. Introduction T he ability of cells to receive and act on signals from beyond the plasma membrane is fundamental to life and is termed bio signaling.
- 4. Introduction T he ability of cells to receive and act on signals from beyond the plasma membrane is fundamental to life and is termed bio signaling. www.fpnotebook.com
- 5. Introduction T he ability of cells to receive and act on signals from beyond the plasma membrane is fundamental to life and is termed bio signaling. yaolab.stanford.edu
- 6. Introduction T he ability of cells to receive and act on signals from beyond the plasma membrane is fundamental to life and is termed bio signaling. In these cases, signals represent information that is detected by specific receptors and converted into cellular response which involves chemical processes. Signals (Light,touch,ho rmones,antigen s,nutrients,neu rotransmitters) Recepto rs Cellular Respons e
- 7. Signal transducing system Salient features (1) Specificity and high affinity www.motifolio.com
- 8. Signal transducing system Salient features (2) Cooperativity meyerbio1b.wikispaces.com
- 9. Signal transducing system Salient features (3) Amplification by enzyme cascade agbioinc.com
- 10. Signal transducing system Salient features (4) Integration : Ability of the system to receive multiple signals , integrate them and produce unified response most appropriate to the needs of the cell.
- 11. Signal transducing system Salient features (4) Integration : Ability of the system to receive multiple signals , integrate them and produce unified response most appropriate to the needs of the cell. (5) Desensitization : When a signal is present continuously, desensitization of the receptor system occurs and when the signal falls below threshold, the system gains sensitivity again.
- 12. Types of signal transducing system (1) Gated ion channel Opens or closes in response to concentration of signal ligand (S) or membrane potential. www.clker.com
- 13. Types of signal transducing system (2) Receptor enzyme Ligand binding to extracellular domain stimulates enzyme activity in intracellular domain. www.nature.com Img : Binding of a ligand to receptor tyrosine kinases (RTKs)
- 14. Types of signal transducing system (3) Steroid receptor Steroid binding to a nuclear receptor protein allows the receptor to regulate the expression of specific genes. users.rcn.com
- 15. Types of signal transducing system (4) Serpentine receptor External ligand binding to receptor (R) activates an intracellular GTP-binding protein (G), which regulates an enzyme (Enz) that generates an intracellular second messenger, X. 2012.igem.org
- 16. Types of signal transducing system (5) Receptor with no intrinsic enzyme activity(membrane proteins) Receptors that lack enzymatic activity but attract and activate cytoplasmic enzymes that act on downstream proteins, either by directly converting them to gene-regulating proteins or by activating a cascade of enzymes that finally activates a gene regulator. (6) Adhesion receptor Receptors (adhesion receptors) that interact with macromolecular components of the extracellular matrix (such as collagen) and convey to the cytoskeletal system instructions on cell migration or adherence to the matrix.
- 17. G protein signaling Guanosine nucleotide binding protein is a heterotrimer (with 3 different units) : alpha ,beta and gamma. The alpha unit is bound to GDP and has high affinity for beta and gamma units. The human genome encodes more than 1000 GPCR (G protein coupled receptors) that transduce messages as light ,touch or hormones. sitemaker.umich.edu
- 19. careerrocketeer.com ****Lehninger Principles of Biochemistry David L. Nelson (University of Wisconsin-Madison) , Michael M. Cox (University of Wisconsin-Madison) ***Sixth Edition ©2013 ***The Regulator of G Protein Signaling Family Annual Review of Pharmacology and Toxicology Vol. 40: 235-271 Luc De Vries Bin Zheng Thierry Fischer Eric Elenko and Marilyn G. Farquhar
Editor's Notes
- #17: . The JAK-STAT system exemplifies the first mechanism (Section 12.3); and the TLR4 (Toll) signaling system in humans, the second. : (5)