PT - JOURNAL ARTICLE AU - Just, Sascha AU - Illing, Susann AU - Trester-Zedlitz, Michelle AU - Lau, Elaine K. AU - Kotowski, Sarah J. AU - Miess, Elke AU - Mann, Anika AU - Doll, Christian AU - Trinidad, Jonathan C. AU - Burlingame, Alma L. AU - von Zastrow, Mark AU - Schulz, Stefan TI - Differentiation of Opioid Drug Effects by Hierarchical Multi-Site Phosphorylation AID - 10.1124/mol.112.082875 DP - 2013 Mar 01 TA - Molecular Pharmacology PG - 633--639 VI - 83 IP - 3 4099 - http://molpharm.aspetjournals.org/content/83/3/633.short 4100 - http://molpharm.aspetjournals.org/content/83/3/633.full SO - Mol Pharmacol2013 Mar 01; 83 AB - Differences in the ability of opioid drugs to promote regulated endocytosis of μ-opioid receptors are related to their tendency to produce drug tolerance and dependence. Here we show that drug-specific differences in receptor internalization are determined by a conserved, 10-residue sequence in the receptor’s carboxyl-terminal cytoplasmic tail. Diverse opioids induce receptor phosphorylation at serine (S)375, present in the middle of this sequence, but opioids differ markedly in their ability to drive higher-order phosphorylation on flanking residues [threonine (T)370, T376, and T379]. Multi-phosphorylation is required for the endocytosis-promoting activity of this sequence and occurs both sequentially and hierarchically, with S375 representing the initiating site. Higher-order phosphorylation involving T370, T376, and T379 specifically requires GRK2/3 isoforms, and the same sequence controls opioid receptor internalization in neurons. These results reveal a biochemical mechanism differentiating the endocytic activity of opioid drugs.