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BIMM118
Regulation of Receptors
• Heterologous desensitization:
– Four residues in the cytosolic domain of the β-adrenergic receptor
can be phosphorylated by PKA
– Activity of all Gs protein – coupled receptors, not just the βadrenergic
receptor, is reduced
• Homologous desensitization:
– Other residues in the cytosolic domain of the β-adrenergic
receptor are phosphorylated by the receptor-specific β-adrenergic
receptor kinase (BARK)
– BARK only phosphorylates the β-adrenergic receptor which
facilitates β-arrestin binding to the phosphorylated receptor