Cellular Communication

Cellular Communication

1. Extracellular communication

   • direct contact: Gap Junctions
     • connexons
       • dock together to form channels between cells
   • cells not touching: secretions
     • autocrine secretions
       • effect on same cell
     • paracrine secretions
       • effect on nearby cells
     • endocrine secretions
       • effects distant cells
     • neurotransmitters
       • substances released by nerve terminal into synapse

2. Intracellular Communication

   • signal transduction
     • signal (ligand)
       • receptor
         • signalling proteins
           • second messengers
             • amplify signals
               • effectors
           • G-proteins
           • protein kinases
           • calcium-binding proteins
           • adenylyl cyclase
           • lipid kinases
         • g-protein coupled receptor
         • ion channel receptors
         • guanylate cyclase
         • protein kinase receptor
         • transmembrane scaffolds
         • nuclear receptors
       • membrane impermeable
       • membrane permeable
       • physical signal
     • linear=1receptor w/ 1 signalling protein/2nd messenger
     • convergent=several receptors share common signalling proteins/2nd messengers
     • divergent=single receptor w/ multiple signalling proteins/2nd messengers
     • multi-branched= combination of convergence and divergence