title: Inhibition of biosynthesis of human endothelin B receptor by the cyclodepsipeptide cotransin.
abstract: The specific inhibition of the biosynthesis of target proteins is a relatively novel strategy in pharmacology and is based mainly on antisense approaches (e.g. antisense oligonucleotides or RNA interference). Recently, a novel class of substances was described acting at a later step of protein biosynthesis. The cyclic heptadepsipeptides CAM741 and cotransin were shown to inhibit selectively the biosynthesis of a small subset of secretory proteins by preventing stable insertion of the nascent chains into the Sec61 translocon complex at the endoplasmic reticulum membrane (Besemer, J., Harant, H., Wang, S., Oberhauser, B., Marquardt, K., Foster, C. A., Schreiner, E. P., de Vries, J. E., Dascher-Nadel, C., and Lindley, I. J. (2005) Nature 436, 290-293; Garrison, J. L., Kunkel, E. J., Hegde, R. S., and Taunton, J. (2005) Nature 436, 285-289). These peptides act in a signal sequence-discriminatory manner, which explains their selectivity. Here, we have analyzed the cotransin sensitivity of various G protein-coupled receptors in transfected HEK 293 cells. We show that the biosynthesis of the human endothelin B receptor (ET(B)R) is highly sensitive to cotransin, in contrast to that of the other G protein-coupled receptors analyzed. Using a novel biosynthesis assay based on fusions with the photoconvertible Kaede protein, we show that the IC(50) value of cotransin action on ET(B)R biosynthesis is 5.4 μm and that ET(B)R signaling could be completely blocked by treating cells with 30 μm cotransin. Taken together, our data add an integral membrane protein, namely the ET(B)R, to the small group of cotransin-sensitive proteins.
authors.affiliation: Leibniz-Institut für Molekulare Pharmakologie, Robert-Rössle-Strasse 10, 13125 Berlin, Germany.
authors.forename: Carolin
authors.initials: C
authors.lastname: Westendorf
authors.affiliation: Max-Delbrück-Centrum für Molekulare Medizin, Robert-Rössle-Strasse 10, 13125 Berlin, Germany.
authors.forename: Antje
authors.initials: A
authors.lastname: Schmidt
authors.affiliation: Salk Institute for Biological Studies, La Jolla, California 92037-1099.
authors.forename: Irene
authors.initials: I
authors.lastname: Coin
authors.affiliation: Leibniz-Institut für Molekulare Pharmakologie, Robert-Rössle-Strasse 10, 13125 Berlin, Germany.
authors.forename: Jens
authors.initials: J
authors.lastname: Furkert
authors.affiliation: Leibniz-Institut für Molekulare Pharmakologie, Robert-Rössle-Strasse 10, 13125 Berlin, Germany; Bereich Molekulare Pharmakologie und Zellbiologie, Charité-Universitätsmedizin Berlin, Thielallee 67-73, 14195 Berlin, Germany.
authors.forename: Ingrid
authors.initials: I
authors.lastname: Ridelis
authors.affiliation: Leibniz-Institut für Molekulare Pharmakologie, Robert-Rössle-Strasse 10, 13125 Berlin, Germany.
authors.forename: Dimitris
authors.initials: D
authors.lastname: Zampatis
authors.affiliation: Leibniz-Institut für Molekulare Pharmakologie, Robert-Rössle-Strasse 10, 13125 Berlin, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Rutz
authors.affiliation: Leibniz-Institut für Molekulare Pharmakologie, Robert-Rössle-Strasse 10, 13125 Berlin, Germany.
authors.forename: Burkhard
authors.initials: B
authors.lastname: Wiesner
authors.affiliation: Max-Delbrück-Centrum für Molekulare Medizin, Robert-Rössle-Strasse 10, 13125 Berlin, Germany; Bereich Molekulare Pharmakologie und Zellbiologie, Charité-Universitätsmedizin Berlin, Thielallee 67-73, 14195 Berlin, Germany.
authors.forename: Walter
authors.initials: W
authors.lastname: Rosenthal
authors.affiliation: Leibniz-Institut für Molekulare Pharmakologie, Robert-Rössle-Strasse 10, 13125 Berlin, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Beyermann
authors.affiliation: Leibniz-Institut für Molekulare Pharmakologie, Robert-Rössle-Strasse 10, 13125 Berlin, Germany. Electronic address: schuelein@fmp-berlin.de.
authors.forename: Ralf
authors.initials: R
authors.lastname: Schülein
mesh_terms: D057809:HEK293 Cells; D006801:Humans; D008164:Luminescent Proteins / Q000096:biosynthesis / Q000235:genetics; D010456:Peptides, Cyclic / Q000494:pharmacology*; D014176:Protein Biosynthesis / Q000187:drug effects* / Q000235:genetics; D044023:Receptor, Endothelin B / Q000096:biosynthesis* / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics
chemical_list: C513582:Kaede protein, Trachyphyllia geoffroyi; D008164:Luminescent Proteins; D010456:Peptides, Cyclic; D044023:Receptor, Endothelin B; D011993:Recombinant Fusion Proteins; C502316:cotransin