a small-molecule inhibitor of t. gondii motility induces the posttranslational modification of myosin light chain-1 and inhibits myosin motor activity弓形虫蠕动的小分子抑制剂诱导肌凝蛋白光的转译后的修改chain-1和抑制肌球蛋白马达活动.pdfVIP

A Small-Molecule Inhibitor of T. gondii Motility Induces the Posttranslational Modification of Myosin Light Chain-1 and Inhibits Myosin Motor Activity 1 1 1 2 3 Aoife T. Heaslip , Jacqueline M. Leung , Kimberly L. Carey , Federica Catti , David M. Warshaw , 2 4 1 Nicholas J. Westwood , Bryan A. Ballif , Gary E. Ward * 1 Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, Vermont, United States of America, 2 School of Chemistry and Centre for Biomolecular Sciences, University of St Andrews, North Haugh, St Andrews, Fife, Scotland, United Kingdom, 3 Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, Vermont, United States of America, 4 Department of Biology and Vermont Genetics Network Proteomics Facility, University of Vermont, Burlington, Vermont, United States of America Abstract Toxoplasma gondii is an obligate intracellular parasite that enters cells by a process of active penetration. Host cell penetration and parasite motility are driven by a myosin motor complex consisting of four known proteins: TgMyoA, an unconventional Class XIV myosin; TgMLC1, a myosin light chain; and two membrane-associated proteins, TgGAP45 and TgGAP50. Little is known about how the activity of the myosin motor complex is regulated. Here, we show that treatment of parasites with a recently identified small-molecule inhibitor of invasion and motility results in a rapid and irreversible change in the electrophoretic mobility of TgMLC1. While the precise nature of the TgMLC1 modification has not yet been established, it was m