Wortmannin is a widely used pharmaceutical compound which is employed to define vesicular trafficking routes of particular proteins or cellular compounds. It targets phosphatidylinositol 3-kinase and phosphatidylinositol 4-kinases in a dose-dependent manner leading to the inhibition of protein vacuolar sorting and endocytosis. Combined proteomics and cell biological approaches have been used in this study to explore the effects of wortmannin on Arabidopsis root cells, especially on proteome and endomembrane trafficking. On the subcellular level, wortmannin caused clustering, fusion, and swelling of trans-Golgi network (TGN) vesicles and multivesicular bodies (MVBs) leading to the formation of wortmannin-induced multivesicular compartments. Appearance of wortmannin-induced compartments was associated with depletion of TGN as revealed by electron microscopy. On the proteome level, wortmannin induced massive changes in protein abundance profiles. Wortmannin-sensitive proteins belonged to various functional classes. An inhibition of vacuolar trafficking by wortmannin was related to the downregulation of proteins targeted to the vacuole, as showed for vacuolar proteases. A small GTPase, RabA1d, which regulates vesicular trafficking at TGN, was identified as a new protein negatively affected by wortmannin. In addition, Sec14 was upregulated and PLD1 alpha was downregulated by wortmannin.

• MeSH
• Androstadienes pharmacology   MeSH
• Arabidopsis cytology   drug effects   metabolism   MeSH
• Phospholipase D metabolism   MeSH
• Plant Roots cytology   drug effects   metabolism   MeSH
• Multivesicular Bodies drug effects   metabolism   MeSH
• Arabidopsis Proteins metabolism   MeSH
• Phospholipid Transfer Proteins metabolism   MeSH
• Proteome metabolism   MeSH
• rab GTP-Binding Proteins metabolism   MeSH
• trans-Golgi Network drug effects   metabolism   ultrastructure   MeSH
• Protein Transport drug effects   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH