ApiLoc - A database of published protein sub-cellular localisation in Apicomplexa

version 3 (curated until May 28, 2011)

Toxoplasma gondii myosin A and its light chain: a fast, single-headed, plus-end-directed motor.

Herm-Gotz, A., Weiss, S., Stratmann, R., Fujita-Becker, S., Ruff, C., Meyhofer, E., Soldati, T., Manstein, D. J., Geeves, M. A., Soldati, D. (2002 May 1, EMBO J)

Successful host cell invasion is a prerequisite for survival of the obligate intracellular apicomplexan parasites and establishment of infection. Toxoplasma gondii penetrates host cells by an active process involving its own actomyosin system and which is distinct from induced phagocytosis. Toxoplasma gondii myosin A (TgMyoA) is presumed to achieve power gliding motion and host cell penetration by the capping of apically released adhesins towards the rear of the parasite. We report here an extensive biochemical characterization of the functional TgMyoA motor complex. TgMyoA is anchored at the plasma membrane and binds a novel type of myosin light chain (TgMLC1). Despite some unusual features, the kinetic and mechanical properties of TgMyoA are unexpectedly similar to those of fast skeletal muscle myosins. Microneedle-laser trap and sliding velocity assays established that TgMyoA moves in unitary steps of 5.3 nm with a velocity of 5.2 microm/s towards the plus end of actin filaments. TgMyoA is the first fast, single-headed myosin and fulfils all the requirements for power parasite gliding.

PubMed: 11980712, full text

Localisation information

TGME49_057680 (MLC1) myosin light chain TgMLC1

Experimental localisation: parasite plasma membrane, multi-lamellar vesicle
  • Species: Toxoplasma gondii
  • Quote inferring localisation: "As anticipated for a TgMyoA-associated protein, TgMLC1 localized at the parasite plasma membrane under static conditions (intracellular parasites) (Figure 2C). In addition, during host cell penetration, TgMLC1 was slightly concentrated at the moving junction and in the part of the parasite penetrating the host cell (Figure 2A). Less than 10 min later, TgMLC1 was still distributed at the parasite periphery but also revealed a circle at the posterior end, delineating an open 'appendage' at the parasite posterior extremity (Figure 2B). This structure, visible only shortly after invasion, is likely to correspond to the transient posterior invagination where multi-lamellar vesicles are released to form the intravacuolar network (Sibley et al 1995)."
  • Microscopy type: Light
  • Microscopy method: polyclonal antibody directly to protein
  • Strain:
  • Gene model mapping comments: blast from AY048862, annotation matches
  • Localisation record: surface and multi-lamellar vesicles
  • Comment: couldn't find strain information for microscopy

TGME49_033460 (SAG1, SRS29B, P30/SAG1, BSR4, P30) SRS29B (= SAG1, P30)

Experimental localisation: parasite plasma membrane during extracellular tachyzoite, parasite plasma membrane during intracellular tachyzoite
  • Species: Toxoplasma gondii
  • Quote inferring localisation: "The major surface antigen (SAG1) is detected prior to permeabilization to label the extracellular portion of the penetrating parasites preferentially, while TgMLC1 was visualized after permeabilization"
  • Microscopy type: Light
  • Microscopy method: polyclonal antibody directly to protein
  • Strain:
  • Gene model mapping comments: inferred from another publication
  • Localisation record: surface during extracellular tachyzoite and intracellular tachyzoite
  • Comment: couldn't find strain information for microscopy