GPCRs

GPCRs

1. Features

   • Amplification
     • G proteins
       • Enzyme activation
     • Phosphorylation Cascades
   • Specificity
     • How selective a drug is for a receptor
     • Clean Drug
       • Only acts on one receptor
     • Dirty drug
       • Drug acts on many receptors 
   • Desensitisation
     • Results in: 1) turning off the receptor  2) removing it from the surface 
     • Receptor turns off
       • Normally by phosphorylating receptor 
     • Removing it from the surface
       • Called internalisation  Can be short or long term  Long term causes increase or decrease in receptor expression
   • Intergration
     • Cell recieves multiple signals and turns it into a response, normally when there are opposing effects on 2nd messengers 
     • Net effect is the sum of the 2 receptor types (e.g. pars/sympathetic systems)