University:
University of Wolverhampton
Course:
4PY019 | Pharmacy
Academic year:

2024
Views:

249

Pages:

21
Author:

Sara

Introduction to the Cell (Cell-Cell Communication) 4PY019 Dr Katherine Karakoula, Prof Angel Armesilla Introduction to the Cell (Cell-Cell Communication) 4PY019 Recommended Reading 5th Edition 7th Edition 4th Edition 7th Edition 8th Edition 10th Edition Cell-Cell Communication Unicellular Organism 2.5 billion years Extracellular signal (protein, peptide, steroids, gas, etc) Sophisticated Multicellular Organism Cell-Cell Intercellular Communication Short Distance Long Distance Contact-dependent Synaptic Paracrine Endocrine Autocrine Extracellular signals lead to specific cell responses Extracellular signals trigger intracellular signaling pathways Different type of cells respond differently to the same extracellular signal molecule Acetylcholine Cardiomyocyte Skeletal muscle cell Salivary gland cell Signal Transducers Cell-Surface Proteins Depending on the signal that activates the protein (or proteins complex): • Voltage-gated (voltage operated) Ion-Channels Ion channels are activated by changes in the membrane potential of the plasma membrane • Ligand-gated (Ligand operated) Receptors - Ion-Channel-Coupled Receptors - G-Protein-Coupled Receptors - Enzyme-Coupled Receptors Signal Transducers Cell-Surface Proteins Depending on the signal that activates the protein (or proteins complex): • Voltage-gated (voltage operated) Ion-Channels Ion channels are activated by changes in the membrane potential of the plasma membrane depolarization Na+ Na+ ++ -- -- -- -- -- ++ ++ ++ ++ Na+ Signal Transducers Cell-Surface Proteins • Ligand-gated (Ligand operated) Receptors - Ion-Channel-Coupled Receptors - G Protein-Coupled Receptors - Enzyme-Coupled Receptors Ligand-gated (Ligand operated) Receptors Ion-Channel-Coupled Receptors Ligand-gated Acetylcholine Receptor (Nicotinic Cholinergic Receptors) Nicotine Agonist Structure Mechanism of Action Ligand-gated (Ligand operated) Receptors Types of Cholinergic Nicotinic Receptors • • Nerve impulse Nn (CNS) Nm (Skeletal Muscle) Nerve impulse ACh Nm Nn Pre-ganglionic neuron ACh Post-ganglionic neuron Skeletal Muscle Cell Ligand-gated (Ligand operated) Receptors - Ion-Channel-Coupled Receptors -G Protein-Coupled Receptors - Enzyme-Coupled Receptors Extracellular signal Signaling protein G-Protein Cellular response Ligand-gated (Ligand operated) Receptors - Ion-Channel-Coupled Receptors -G Protein-Coupled Receptors - Enzyme-Coupled Receptors G-protein Regulated Signalling Proteins • Adenylyl Cyclase • Phospholipase C G-protein α-subunits • Gαs or Gαi (activate or inhibit Adenylyl Cyclase) • Gαq (activates)Phospholipase C Ligand-gated (Ligand operated) Receptors - Ion-Channel-Coupled Receptors -G Protein-Coupled Receptors - Enzyme-Coupled Receptors G protein-coupled adenylyl cyclase-cAMP pathway G protein-coupled Phospholipase C pathway Major G Protein-Coupled Receptors Muscarinic Cholinergic Receptors Acetylcholine Types of Muscarinic receptors Muscarine Agonist α β γ M1 αq M2 αi M3 αq M4 M5 Major G Protein-Coupled Receptors Muscarinic Cholinergic Receptors M1 αq Activates PLC Stomach release HCl and pepsinogen M2 αi Inhibits AC Decrease Heart Rate and contractitily M3 αq Activates PLC Salivary Gland Secretion M4 M5 Major G Protein-Coupled Receptors Adrenergic Receptors +++ + Adrenaline (Epinephrin) Nor-Adrenaline (Nor-Epinephrin) +++ Nor-Adrenaline (Nor-Epinephrin) + Adrenaline (Epinephrin) G-Protein G-Protein Major G Protein-Coupled Receptors Adrenergic Receptors α1 αq Activates PLC Vasoconstriction peripheral Vessels α2 αi Inhibits AC Inhibits release neurotransmitters β1 αs Activates AC Increase Heart Rate and contractility β2 αs Activates AC β3 Vasodilation of Vessels Bronco-dilation Ligand-gated (Ligand operated) Receptors - Ion-Channel-Coupled Receptors - G Protein-Coupled Receptors - Enzyme-Coupled Receptors Epidermal Growth Factor Receptor Ligand-gated (Ligand operated) Receptors - Ion-Channel-Coupled Receptors - G Protein-Coupled Receptors - Enzyme-Coupled Receptors Insulin Receptor