Unusual Anchor of a Motor Complex (MyoD-MLC2) to the Plasma Membrane of Toxoplasma gondii

Abstract

Toxoplasma gondii possesses 11 rather atypical myosin heavy chains. The only myosin light chain described to date is MLC1, associated with myosin A, and contributing to gliding motility. In this study, we examined the repertoire of calmodulin-like proteins in Apicomplexans, identified six putative myosin light chains and determined their subcellular localization in T. gondii and Plasmodium falciparum. MLC2, only found in coccidians, is associated with myosin D via its calmodulin (CaM)-like domain and anchored to the plasma membrane of T. gondii via its N-terminal extension. Molecular modeling suggests that the MyoD-MLC2 complex is more compact than the reported structure of Plasmodium MyoA-myosin A tail-interacting protein (MTIP) complex. Anchorage of this MLC2 to the plasma membrane is likely governed by palmitoylation