PF3D7_1401200

PF3D7_1401200 is a Plasmodium falciparum exported protein that operates in the infected red blood cell compartment as a physical partner of the RhopH complex (PMID:33774908). In reciprocal immunoprecipitation and mass spectrometry assays, it associated with all three RhopH members—CLAG3, RhopH2, and RhopH3—and showed the strongest association among 13 tested exported proteins, marking it as a prominent RhopH-interacting factor rather than an incidental one (PMID:33774908). Despite this association, conditional knockdown of PF3D7_1401200 did not alter sorbitol uptake, indicating it is not individually required for new permeability pathway (NPP) activity at the red blood cell membrane (PMID:33774908). Beyond this RhopH-complex association and the NPP-dispensability result, the corpus establishes no independent molecular function, catalytic activity, or structure for PF3D7_1401200; its role remains defined only through its interaction with the RhopH complex.

1. 2021 Medium

   It was unknown which exported proteins engage the RhopH complex in the host cell; testing a panel of exported proteins established PF3D7_1401200 as the strongest RhopH-associating candidate, placing it in the machinery surrounding CLAG3/RhopH2/RhopH3.

   Evidence Reciprocal co-immunoprecipitation and mass spectrometry across 13 tested exported proteins in P. falciparum-infected red blood cells

   PMID:33774908

   Open questions at the time

   • Direct versus indirect binding within the complex not resolved
   • Interaction interface and stoichiometry unknown
   • Whether the association is constitutive or stage/condition-dependent not tested
2. 2021 Medium

   Given the RhopH complex's link to solute transport, the key question was whether PF3D7_1401200 contributes to NPP function; conditional knockdown with no effect on sorbitol uptake showed it is dispensable for NPP activity individually.

   Evidence Conditional knockdown coupled to sorbitol-uptake NPP assay in P. falciparum

   PMID:33774908

   Open questions at the time

   • Possible redundancy with other exported partners not excluded
   • Non-NPP functions of the protein not assessed
   • Effect of knockdown on RhopH complex assembly, trafficking, or stability not measured

• The intrinsic molecular function of PF3D7_1401200 and the purpose of its strong RhopH association remain undefined.
• No molecular activity or substrate identified
• No structural model or domain assignment
• Functional consequence of the RhopH interaction for the parasite unknown