Reconstitution of the core of the malaria parasite glideosome with recombinant Plasmodium class XIV myosin A and Plasmodium actin.
File(s)J. Biol. Chem.-2017-Bookwalter-jbc.M117.813972.pdf (3.92 MB)
Accepted version
Author(s)
Type
Journal Article
Abstract
Motility of the apicomplexan malaria parasite Plasmodium falciparum is enabled by a multi-protein glideosome complex, whose core is the class XIV myosin motor, PfMyoA and a divergent Plasmodium actin (PfACT1). Parasite motility is necessary for host cell invasion and virulence, but studying its molecular basis has been hampered by unavailability of sufficient amounts of PfMyoA. Here, we expressed milligram quantities of functional full-length PfMyoA with the baculovirus/Sf9 cell expression system, which required a UCS (UNC-45/CRO1/She4p) family myosin chaperone from Plasmodium spp. In addition to the known light chain MTIP, we identified an essential light chain (PfELC) that co-purified with PfMyoA isolated from parasite lysates. The speed at which PfMyoA moved actin was fastest with both light chains bound, consistent with the light chain-binding domain acting as a lever arm to amplify nucleotide-dependent motions in the motor domain. Surprisingly, PfELC binding to the heavy chain required that MTIP also be bound to the heavy chain, unlike MTIP that bound the heavy chain independently of PfELC. Neither the presence of calcium nor deletion of the MTIP N-terminal extension changed the speed of actin movement. Of note, PfMyoA moved filaments formed from Sf9 cell-expressed PfACT1 at the same speed as skeletal muscle actin. Duty ratio estimates suggested that as few as nine motors can power actin movement at maximal speed, a feature that may be necessitated by the dynamic nature of Plasmodium actin filaments in the parasite. In summary, we have reconstituted the essential core of the glideosome, enabling drug targeting of both of its core components to inhibit parasite invasion.
Date Issued
2017-10-04
Date Acceptance
2017-10-04
Citation
Journal of Biological Chemistry, 2017, 292, pp.19290-19303
ISSN
0021-9258
Publisher
American Society for Biochemistry and Molecular Biology
Start Page
19290
End Page
19303
Journal / Book Title
Journal of Biological Chemistry
Volume
292
Copyright Statement
Copyright 2017 by The American Society for Biochemistry and Molecular Biology, Inc.
Sponsor
Wellcome Trust
Wellcome Trust
Human Frontier Science Program
Identifier
PII: M117.813972
Grant Number
100993/Z/13/Z
100993/Z/13/Z
RGY0066/2016
Subjects
Plasmodium falciparum, myosin XIV, glideosome, malaria, myosin light chain, MTIP, UCS family chapero
actin
chaperone
malaria
myosin
parasite
Publication Status
Published