Adenyl cyclase signaling slideshare

Introduction to Cell Signaling; G-Protein Coupled Receptorsa & class; Adenyl Cyclase - Class, Reaction, AC Signaling pathway; Example- Beta adrenergic receptor & Odorant receptor, AC stimulation & inhibition.

1. ADENYLYL CYCLASE SIGNALING PREPARED BY :- ARUNDHATI MEHTA SEMESTER :- M.Sc. BIOTECH I DEPARTMENT OF BIOTECHNOLOGY © Arundhati Mehta 2016

2. INTRODUCTION SIGNAL TRANSDUCTION is any process by which a cell converts one kind of signal or stimulus into another. It is the ability of cell to perceive and correctly respond to their microenvironment for various cell activity. Sensitivity of a Cell to External Signals is determined by the Number of Surface Receptors. Appropriate Cellular Responses depend on interaction and regulation of signalling pathways. G protein–coupled receptors (GPCRs) constitute a large protein family of receptors, that sense molecules outside the cell and activate inside signal transduction pathways and, ultimately , cellular responses.

3. GPCRs & their associated effectors, 2 nd Messenger.

4. ADENYLYL CYCLASE commonly known as   adenyl cyclase  & adenylate cyclase . It is an integral polyphyletic protein of the plasma membrane, with its active site on the cytosolic face.  The best known class of adenylyl cyclases is class III or AC-III (Roman numerals are used for classes). AC-III occurs widely in eukaryotes and has important roles in many human tissues. Adenylyl cyclase catalyzes the conversion of  ATP  to  3',5'-cyclic AMP

5. ADENYL CYCLASE SIGNALING Interaction of G s a with adenyl cyclase

6. b- A drenergic Receptor The  beta-2 adrenergic receptor  ( β 2   adrenoreceptor ), also known as  ADRB2 , is a cell membrane-spanning  beta-adrenergic receptor  that interacts with epinephrine , a hormone and  neurotransmitter  ( ligand synonym, adrenaline ) whose signaling , physiologic responses  CELLS / TISSUE RECEPTOR FUNCTIONS Hepatocytes ( Liver ) Glycogenolysis Heart muscle cells Increase contraction rate of heart Smooth muscle cells of blood vessels Relax blood supply to other organs like kidney, intestine, skin etc Pancreas Insulin secretion ( increases uptake of glucose by muscle)

7. b- A drenergic Receptor Mechanism

8. b- A drenergic Receptor Mechanism (cont.)

9. Odorant Receptors Olfactory receptors   in the cell membranes of  olfactory receptor neurons .  located in both the cilia and synapses of the olfactory sensory neurons and in the epithelium of the human airway Responsible for the detection of  odor  molecules. These receptors are members of the class A rhodopsin -like  family of  GPCRs. OLFACTORY RECEPTORS Receptor type GPCRs G – Protein Class G olfa Associated Effector Adenyl Cyclase Second Messenger cAMP (increase) Binding specificity  range of odor molecules

10. Odorant Receptors Mechanism

11. Odorant Receptors Mechanism (cont.)

12. Adenyl cyclase Stimulation and Inhibition Gs-GTP and Gi -GTP interact differently with adenylyl cyclase , so that one stimulates and the other inhibits its catalytic activity.