Drug Receptors
Ion Channels
GPCRs (Most Abundant)
Enzymatic Domain
Intracellular
Extracellular
Cell-Surface Adhesion
Ligand-Gated
Voltage Gated
Second Messenger Regulated
G(s)
G(i)
G(o)
G(q)
G(12/13)
Activate Ca channels
Activate adenylyl cyclase
Activate K channels
Inhibit adenylyl cyclase
Inhibit Ca channels
Activate phospholipase C
Diverse ion transporter interactions
Receptor Tyrosine Kinases
Receptor Tyrosine Phosphatases
Receptor Tyrosine-Associated Kinases
Receptor Serine/Threorine Kinases
Adds phosphate to tyrosine residues
Removes phosphate from tyrosine residues
Dimerization activates a tyrosine kinase
Adds phosphate to serine or threonine residues
Enzymes
Transcription Factors
Structural Proteins
Signaling cascades and apoptosis
DNA transcription regulation
RNA interference and microtubule disruption
Communication between cells
Integrin binding
Function like velcro
Receptor Regulation Mechanisms
Tachyphylaxis
Desensitization
Inactivation
Refractoriness
Down-Regulation
Repeated administration of a drug results in diminishing effect
Homologous
Heterologous
Decreased response at one receptor
Decreased response coordinated by 2+ receptors
Loss of ability to respond to stimulation by drug
Covalent bonding
Suicide substrate
Period of time required before initiating another response
Voltage gated sodium channels
Repeated interaction at receptor results in removal of receptors from plasma membrane
Via endocytosis
Receptor Guanylyl Cyclases
Activate guanylyl cyclase directly
Role in cell growth, differentiation, cancer