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

version 3 (curated until May 28, 2011)

Concerted action of two formins in gliding motility and host cell invasion by Toxoplasma gondii.

Daher, W., Plattner, F., Carlier, M. F., Soldati-Favre, D. (2010, PLoS Pathog)

The invasive forms of apicomplexan parasites share a conserved form of gliding motility that powers parasite migration across biological barriers, host cell invasion and egress from infected cells. Previous studies have established that the duration and direction of gliding motility are determined by actin polymerization; however, regulators of actin dynamics in apicomplexans remain poorly characterized. In the absence of a complete ARP2/3 complex, the formin homology 2 domain containing proteins and the accessory protein profilin are presumed to orchestrate actin polymerization during host cell invasion. Here, we have undertaken the biochemical and functional characterization of two Toxoplasma gondii formins and established that they act in concert as actin nucleators during invasion. The importance of TgFRM1 for parasite motility has been assessed by conditional gene disruption. The contribution of each formin individually and jointly was revealed by an approach based upon the expression of dominant mutants with modified FH2 domains impaired in actin binding but still able to dimerize with their respective endogenous formin. These mutated FH2 domains were fused to the ligand-controlled destabilization domain (DD-FKBP) to achieve conditional expression. This strategy proved unique in identifying the non-redundant and critical roles of both formins in invasion. These findings provide new insights into how controlled actin polymerization drives the directional movement required for productive penetration of parasites into host cells.

PubMed: 20949068, full text

Localisation information

TGME49_006430 (Formin1, FRM1) formin homology 2 domain-containing protein

Experimental localisation: parasite plasma membrane during intracellular tachyzoite, parasite plasma membrane during extracellular tachyzoite, not exclusively apical plasma membrane during intracellular tachyzoite, not exclusively apical plasma membrane during extracellular tachyzoite
  • Species: Toxoplasma gondii
  • Quote inferring localisation: "Upon aerolysin treatment, TgFRM1 remained associated with the PM, whereas TgFRM2 stayed preferentially connected to the IMC"
  • Microscopy type: fixed light
  • Microscopy method: antibody
  • Strain: RH HXGPRT-
  • Gene model mapping comments: inferred from another publication
  • Localisation record: PM and not selectively apical PM during intracellular tachyzoite and extracellular tachyzoite

TGME49_006580 (FRM2) hypothetical protein, conserved

Experimental localisation: inner membrane complex during intracellular tachyzoite, inner membrane complex during extracellular tachyzoite
  • Species: Toxoplasma gondii
  • Quote inferring localisation: "Upon aerolysin treatment, TgFRM1 remained associated with the PM, whereas TgFRM2 stayed preferentially connected to the IMC"
  • Microscopy type: fixed light
  • Microscopy method: antibody
  • Strain: RH HXGPRT-
  • Gene model mapping comments: Blast from TGSYPGASDKSQQTFS taken from figure 1
  • Localisation record: IMC during intracellular tachyzoite and extracellular tachyzoite

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

Experimental localisation: parasite plasma membrane during intracellular tachyzoite, parasite plasma membrane during extracellular tachyzoite
  • Species: Toxoplasma gondii
  • Quote inferring localisation: "SAG1 and GAP45 are used as markers of PM and IMC, respectively."
  • Microscopy type: fixed light
  • Microscopy method: antibody
  • Strain: RH HXGPRT-
  • Gene model mapping comments: inferred from another publication
  • Localisation record: PM during intracellular tachyzoite and extracellular tachyzoite

TGME49_023940 (GAP45) hypothetical protein

Experimental localisation: inner membrane complex during intracellular tachyzoite
  • Species: Toxoplasma gondii
  • Quote inferring localisation: "SAG1 and GAP45 are used as markers of PM and IMC, respectively."
  • Microscopy type: fixed light
  • Microscopy method: antibody
  • Strain: RH HXGPRT-
  • Gene model mapping comments: inferred from another publication
  • Localisation record: IMC during intracellular tachyzoite

TGME49_029010 (RON4) hypothetical protein

Experimental localisation: moving junction during intracellular tachyzoite, moving junction during extracellular tachyzoite
  • Species: Toxoplasma gondii
  • Quote inferring localisation: "RON4 is a marker of the moving junction (MJ)"
  • Microscopy type: fixed light
  • Microscopy method: antibody
  • Strain: RH HXGPRT-
  • Gene model mapping comments: inferred from another publication
  • Localisation record: moving junction during intracellular tachyzoite and extracellular tachyzoite