S-palmitoylation modulates human estrogen receptor-alpha functions.
17beta-Estradiol (E2)-induced rapid functions (from seconds to minutes) can be attributed to a fraction of nuclear estrogen receptor-alpha (ERalpha) localized at the plasma membrane. As a potential mechanism, we postulated that S-palmitoylation of the Cys447 residue may explain the ability of ERalpha to associate to plasma membrane making possible E2-dependent rapid functions [e.g., extracellular regulated kinase (ERK) activation]. Here, we report direct evidence that the mutation of the Cys447 residue to Ala impairs human ERalpha palmitoylation and E2-induced rapid ERK phosphorylation when transfected in ER-devoid HeLa cells. Moreover, the Cys447Ala mutation significantly decreases the E2-induced transactivation of an estrogen responsive element construct probe. Similar effects were obtained treating HeLa cells transfected with wild type ERalpha with the palmitoyl-acyltransferase inhibitor 2-bromo-hexadecanoic acid. Moreover, the deletion of the A-D domains (containing the DNA binding region) of ERalpha had no consequences on [(3)H]palmitate incorporation, whereas no palmitoylation occurred in the ERalpha mutant devoid of the E domain (i.e., ligand binding domain). These results point to the pivotal role of the Cys447 residue in ERalpha palmitoylation and in the modulation of E2-induced non-genomic functions.
Acconcia
Filippo
F
Department of Biology, University Roma Tre, Viale G. Marconi, 446, I-00146, Rome, Italy.
Ascenzi
Paolo
P
Fabozzi
Giulia
G
Visca
Paolo
P
Marino
Maria
M
D000409:Alanine / Q000737:chemistry; D015153:Blotting, Western; D002462:Cell Membrane / Q000378:metabolism; D003545:Cysteine / Q000737:chemistry; D004789:Enzyme Activation; D047628:Estrogen Receptor alpha; D017353:Gene Deletion; D006367:HeLa Cells; D006801:Humans; D007004:Hypoglycemic Agents / Q000494:pharmacology; D015151:Immunoblotting; D008156:Luciferases / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D019308:Palmitic Acid / Q000378:metabolism*; D010957:Plasmids / Q000378:metabolism; D011233:Precipitin Tests; D017434:Protein Structure, Tertiary; D011960:Receptors, Estrogen / Q000378:metabolism*; D015398:Signal Transduction; D013997:Time Factors; D015533:Transcriptional Activation; D014162:Transfection
D047628:Estrogen Receptor alpha; D007004:Hypoglycemic Agents; D011960:Receptors, Estrogen; D019308:Palmitic Acid; D008156:Luciferases; D020928:Mitogen-Activated Protein Kinases; D003545:Cysteine; D000409:Alanine