TY - JOUR T1 - Inhibition of Vascular Endothelial Growth Factor Cotranslational Translocation by the Cyclopeptolide CAM741 JF - Molecular Pharmacology JO - Mol Pharmacol SP - 1657 LP - 1665 DO - 10.1124/mol.107.034249 VL - 71 IS - 6 AU - Hanna Harant AU - Barbara Wolff AU - Erwin P. Schreiner AU - Berndt Oberhauser AU - Lotte Hofer AU - Nicole Lettner AU - Sabine Maier AU - Jan E. de Vries AU - Ivan J. Lindley Y1 - 2007/06/01 UR - http://molpharm.aspetjournals.org/content/71/6/1657.abstract N2 - The cyclopeptolide CAM741 inhibits cotranslational translocation of vascular cell adhesion molecule 1 (VCAM1), which is dependent on its signal peptide. We now describe the identification of the signal peptide of vascular endothelial growth factor (VEGF) as the second target of CAM741. The mechanism by which the compound inhibits translocation of VEGF is very similar or identical to that of VCAM1, although the signal peptides share no obvious sequence similarities. By mutagenesis of the VEGF signal peptide, two important regions, located in the N-terminal and hydrophobic segments, were identified as critical for compound sensitivity. CAM741 alters positioning of the VEGF signal peptide at the translocon, and increasing hydrophobicity in the h-region reduces compound sensitivity and causes a different, possibly more efficient, interaction with the translocon. Although CAM741 is effective against translocation of both VEGF and VCAM1, the derivative NFI028 is able to inhibit only VCAM1, suggesting that chemical derivatization can alter not only potency, but also the specificity of the compounds. The American Society for Pharmacology and Experimental Therapeutics ER -