Palmitoylation of the human beta 2-adrenergic receptor. Mutation of Cys341 in the carboxyl tail leads to an uncoupled nonpalmitoylated form of the receptor.
We report that a cysteine residue in the human beta 2-adrenergic receptor (beta 2AR) is covalently modified by thioesterification with palmitic acid. By site-directed mutagenesis of the receptor, we have identified Cys341 in the carboxyl tail of the protein as the most likely site of palmitoylation. Mutation of Cys341 to glycine results in a nonpalmitoylated form of the receptor that exhibits a drastically reduced ability to mediate isoproterenol stimulation of adenylyl cyclase. The functional impairment of this mutated beta 2AR is also reflected in a markedly reduced ability to form a guanyl nucleotide-sensitive high affinity state for agonists, characteristic of wild-type receptor. These results indicate that post-translational modification by palmitate of beta 2AR may play a crucial role in the normal coupling of the receptor to the adenylyl cyclase signal transduction system.
O'Dowd
B F
BF
Howard Hughes Medical Institute Laboratories, Duke University Medical Center, Durham, North Carolina 27710.
Hnatowich
M
M
Caron
M G
MG
Lefkowitz
R J
RJ
Bouvier
M
M
D000215:Acylation; D000262:Adenylyl Cyclases / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D003545:Cysteine; D006801:Humans; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D009154:Mutation; D019308:Palmitic Acid; D010169:Palmitic Acids / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D011869:Radioligand Assay; D011943:Receptors, Adrenergic, beta / Q000235:genetics / Q000378:metabolism*; D013329:Structure-Activity Relationship
D008562:Membrane Glycoproteins; D010169:Palmitic Acids; D011943:Receptors, Adrenergic, beta; D019308:Palmitic Acid; D000262:Adenylyl Cyclases; D003545:Cysteine