Recommended
More Related Content
What's hot
What's hot (20)
Similar to G protein coupled receptors new
Similar to G protein coupled receptors new (20)
More from DrRenuYadav2
Recently uploaded
Recently uploaded (20)
G protein coupled receptors new
- 1. G-Protein Coupled Receptors BY- DR. RENU YADAV RESIDENT PHARMACOLOGY
- 2. Contents 1. Receptor and its types 2. Physiology of GPCR 3. GPCR as target for drug designing 4. GPCR associated diseases 5. Future prospects and conclusions
- 3. Definition • A receptor is defined as a macromolecule or binding site located on the surface or inside of the effector cell that serves to recognize the signal molecule/drug and initiate the response to it, but itself has no other function.
- 4. Types of receptors 1. G- protein receptors : largest 2. Ion channel receptors/ ligand gated receptors : fastest 3. Transmembrane enzyme-linked receptors : eg tyrosine kinase 4. Jak-stat receptors : JAK- Janus kinase, STAT – signal transducer and activator of transcription. Eg. Cytokines, GH, prolactin, interferons 5. Nuclear receptors : steroids, thyroxine, vit D, vit A.
- 5. GPCR
- 6. Gs Gq Gi G-Protein is made up of 20 alpha 6 beta subunit 12 gamma subunits GDP Beta-gamma complex
- 8. Actions of G-alpha • Gs Adenylyl cyclase activation Ca channel opening • Gi Adenynyl cyclase inhibition K+ channel opening • Go Ca channel inhibition • Gq Phospholipase C activation
- 9. 3 Major Pathways of GPCR 1.CAMP Dependant Pathway 2. Phospholipase C : IP3- DAG pathway 3. Channel regulation
- 10. cAMP dependant effects 1. Via protein kinase A • Increased contractility of heart • Relaxation of smooth muscles • Glycogenolysis, lipolysis • Water conservation by kidneys • Steroid hormone synthesis 2. cAMP response element binding protein(CREB) 3. EPACs (CAMP regulated guanine nucleotide exchange factors)
- 12. G-PROTEIN RECEPTORS Gs Beta adrenergic Glucagon Histamine Serotonin 5HT4-7 Gi Alpha2 Opioid Serotonin Cannabinoids Gq Apha1 H1 Vasopressin (type1)
- 13. GPCR as drug targets Receptor Drug and some key indication Alpha-1 receptor Antagonist eg Tamsulosin to treat enlarged prostate Beta-1 Antagonists eg propranolol, atenolol for hypertension Beta-2 Agonists in bronchial asthma D-2 Antagonists eg haloperidol , clozapine in schizophrenia Agonists eg levodopa in parkinsons
- 15. Diseases associated with G-proteins 1. Gene mutations: loss of function eg color blindness gain of function 2. Bacterial toxins: Eg cholera 3. Altered GPCR folding
- 16. Orphan GPCR • Receptors which lack their pharmacological identity • Focus of intense research • First orphan GPCR was G21 later found to be 5HT1A
- 17. Recent developments • Ligand- induced selective signalling (LISS): It states that different ligand selectively recruits different intracellular signalling protein to produce different phenotypic effects. • There are many ways GPCR can signal independently of G- proteins. A case has been made to abandon the term as couple receptor and call them transmembrane receptors. • GPCR are new therapeutic targets for type 2 diabetes.