an essential farnesylated kinesin in trypanosoma brucei一个重要farnesylated驱动蛋白在锥虫属brucei.pdfVIP

An Essential Farnesylated Kinesin in Trypanosoma brucei 1,2 1 1,3,4 Erin J. Engelson , Frederick S. Buckner , Wesley C. Van Voorhis * 1 Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, Washington, United States of America, 2 Molecular and Cellular Biology Program, University of Washington, Seattle, Washington, United States of America, 3 Department of Global Health, University of Washington, Seattle, Washington, United States of America, 4 Department of Microbiology, University of Washington, Seattle, Washington, United States of America Abstract Kinesins are a family of motor proteins conserved throughout eukaryotes. In our present study we characterize a novel kinesin, KinesinCaaX, orthologs of which are only found in the kinetoplastids and not other eukaryotes. KinesinCaaX has the CVIM amino acids at the C-terminus, and CVIM was previously shown to be an ideal signal for protein farnesylation in T. brucei. In this study we show KinesinCaaX is farnesylated using radiolabeling studies and that farnesylation is dependent on the CVIM motif. Using RNA interference, we show KinesinCaaX is essential for T. brucei proliferation. Additionally RNAi KinesinCaaX depleted T. brucei are 4 fold more sensitive to the protein farneysltransferase (PFT) inhibitor LN-59, suggesting that KinesinCaaX is a target of PFT inhibitors’ action to block proliferation of T. brucei. Using tetracycline-induced exogenous tagged KinesinCaaX and KinesinCVIMdeletion (non-farnesylated Kinesin) expression lines in T. brucei, we demonstrate KinesinCaaX is farnesylated in T. brucei cells and this farnesylation has functional effects. In cells expressing a CaaX-deleted ver