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

version 3 (curated until May 28, 2011)

Host cell entry by apicomplexa parasites requires actin polymerization in the host cell.

Gonzalez, V., Combe, A., David, V., Malmquist, N. A., Delorme, V., Leroy, C., Blazquez, S., Menard, R., Tardieux, I. (2009 Mar 19, Cell Host Microbe)

Apicomplexa are obligate intracellular parasites that actively invade host cells using their membrane-associated, actin-myosin motor. The current view is that host cell invasion by Apicomplexa requires the formation of a parasite-host cell junction, which has been termed the moving junction, but does not require the active participation of host actin. Using Toxoplasma gondii tachyzoites and Plasmodium berghei sporozoites, we show that host actin participates in parasite entry. Parasites induce the formation of a ring-shaped F-actin structure in the host cell at the parasite-cell junction, which remains stable during parasite entry. The Arp2/3 complex, an actin-nucleating factor, is recruited at the ring structure and is important for parasite entry. We propose that Apicomplexa invasion of host cells requires not only the parasite motor but also de novo polymerization of host actin at the entry site for anchoring the junction on which the parasite pulls to penetrate the host cell.

PubMed: 19286135, full text

Localisation information

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

Experimental localisation: parasite plasma membrane during tachyzoite
  • Species: Toxoplasma gondii
  • Quote inferring localisation: "The constriction of the entering tachyzoite can be localized by immunostaining the surface protein P30, which under nonpermeabilizing conditions sharply demarcates the extra- and intracellular portions of the zoite (Figures 2A–2D, S1A, and S1B), as well as RON4 (Figures 2E, 2F, and S1C), a tachyzoite-secreted protein that redistributes to the MJ ([Lebrun et al., 2005] and [Alexander et al., 2005])."
  • Microscopy type: Light
  • Microscopy method: Monoclonal antibody directly to protein
  • Strain: RH
  • Gene model mapping comments: inferred from another publication
  • Localisation record: surface during tachyzoite

TGME49_029010 (RON4) hypothetical protein

Experimental localisation: moving junction during tachyzoite invasion
  • Species: Toxoplasma gondii
  • Quote inferring localisation: "Tachyzoites were labeled with anti-P30 antibodies under nonpermeabilizing conditions (A–D) or with anti-Ron4 antibodies to stain the MJ (E and F; see white arrows)."
  • Microscopy type: Light
  • Microscopy method: polyclonal antibody directly to protein
  • Strain: RH
  • Gene model mapping comments: inferred from another publication
  • Localisation record: MJ during tachyzoite invasion