Iloprost-induced translocation of a 23-kDa protein that is recognized by a Gs alpha antiserum

We have observed that iloprost, a prostacyclin analog, causes the translocation of a 23-kDa protein from the membrane to the cytosol of human platelets. This 23-kDa protein is recognized by a Gs alpha (alpha subunit of stimulatory guanine nucleotide binding regulatory protein) antiserum but is not ADP-ribosylated by cholera toxin. The translocation of the Gs alpha-related protein might be an important part of the complex chain of events resulting in agonist-induced desensitization.