TYPES OF CELL SIGNALING RECEPTORS

MOLICULAR BIOLOGY AND MICROBIOLOGY

1. Submitted to : Dr. Ravish katiyar Department of Microbiology Presented by- Vinay kumar singh M.Sc.(Microbiology) 3 nd sem . TYPES OF CELL SIGNALING RECEPTORS

2. CONTENTS INTRODUCTION CELL SIGNALING TYEPS OF RECEPTORS INTERNAL RECEPTORS CELL-SURFACE RECEPTORS Ion channel-linked receptors G-protein-coupled receptors Enzyme-linked receptors

3. INTRODUCTION Cells must be ready to respond to essential signals in their environment. These are often chemicals in the extracellular fluid (ECF) from: distant locations –  signaling by hormones; nearby cells  cytokines; or even secreted by themselves . Long-range allostery is often a significant component of cell signaling events

4. CELL SIGNALING Cell signaling is part of a complex system of communication that governs basic cellular activities and coordinates cell actions . The ability of cells to perceive and correctly respond to their microenvironment is the basis of development, tissue repair, and immunity as well as normal tissue homeostasis Errors in cellular information processing are responsible for diseases such as cancer, autoimmunity, and diabetes. By understanding cell signaling, diseases may be treated effectively and, theoretically, artificial tissues may be created .

5. TYEPS OF RECEPTOR A receptor is a protein molecule usually found embedded within the plasma membrane surface of a cell that receives chemical signals from outside the cell and when such chemical signals bind to a receptor, they cause some form of cellular/tissue response There are 2 types of receptors. Those are : Internal & Cell surface receptor .

6. Internal receptor Hydrophobic signaling molecules typically diffuse across the plasma membrane interact with intracellular receptors in the cytoplasm

7. Cell surface receptor . Cell-surface / transmembrane receptors/ cellspecific proteins  performs signal transduction, converting an extracellular signal into an intracellular signal . 3 main components : i . an external ligand -binding domain (extracellular domain ), ii. a hydrophobic membrane-spanning region , iii. and an intracellular domain inside the cell.

8. There are three general categories of cell-surface receptors: Ion channel-linked receptors, 2 . G-protein-linked receptors , 3. Enzyme-linked receptors .

9. Ion Channel-Linked Receptors  Receptors bind with ligand . ( Ex:Nicotinic Receptor )  Open a channel through the membrane that allows specific ions to pass through.  Conformational change in the protein's structure that allows ions such as Na,Ca , Mg, and H2 to pass through .

10. Ion Channel-Linked Receptors

11. G-Protein Linked Receptors  Binds with a ligand and activate a membrane protein called a G-protein.  The activated G-protein then interacts with either an ion channel or an enzyme in the membrane .  Each receptor has its own specific extracellular domain and G-protein-binding site. Example : Beta-adrenergic receptor

12. G-Protein Linked Receptors

13. Enzyme-Linked Receptors  Cell surface receptors with intracellular domains that are associated with an enzyme .  Normally have large extracellular and intracellular domains . When a ligand binds to the extracellular domain, a signal is transferred through the membrane and activates the enzyme, which eventually leads to a response. Example : Tyrosine Kinase receptor

14. Enzyme-Linked Receptors

15. Conclusion #cell plasma membranes (and a few  intracellular membranes  as well) contain membrane receptors. #These receptors mediate  signal transduction  for cellular responses to extracellular stimuli . Membrane receptors are usually  transmembrane proteins . # Transmembrane proteins with part of their mass on both sides of the membrane are poised structurally to transmit information from one side of the membrane to the other .

16. # biology/textbooks/ boundles s-biology-textbook/cell-communication-9/ signalingmolecules -and-cellular-#receptors-83/types-of-receptors381-11607 / # General/ Introductio n/Introobj2.htm 4. A Presentation on “Receptor regulation and receptor related diseases” by “Dr. Plessan Joy” 5 . A Presentation on “Types of cell signalingh Receptors” by “V.K S ingh” ” Reference