ATPTG3

PF3D7_0815400 (ATPTG3) is a putative ATP synthase-associated protein of Plasmodium falciparum that localizes to the mitochondrion, where it is a component of a large (>1 MDa) ATP synthase complex whose mass is consistent with dimeric assembly (PMID:21984828). Its identification alongside six canonical ATP synthase subunits by epitope tagging and blue native gel electrophoresis places it within a complex whose apparent size exceeds the canonical subunit set, indicating additional, divergent subunits (PMID:21984828). Beyond this mitochondrial localization and complex membership, no direct mechanistic experiments have been performed on ATPTG3 itself in the available corpus; its specific molecular role within the ATP synthase complex, its interaction interfaces, and any individual functional requirement remain uncharacterized.

1. 2011 Medium

   To establish whether ATPTG3 is a genuine mitochondrial ATP synthase component, epitope tagging placed it, with six canonical subunits, in the mitochondrion within a >1 MDa complex, establishing both its subcellular localization and its membership in a large dimeric assembly.

   Evidence Epitope tagging with immunofluorescence localization and blue native gel electrophoresis of mitochondrial membranes in transgenic P. falciparum

   PMID:21984828

   Open questions at the time

   • ATPTG3 was one of seven subunits studied collectively and is not individually distinguished functionally
   • No direct evidence of ATPTG3's specific position or role within the complex
   • The identity of the non-canonical subunits inferred from the >1 MDa mass was not resolved
2. 2009 Low

   Computational analysis addressed the question of how the Plasmodium ATP synthase membrane sector is constituted, identifying candidate divergent subunit a and subunit b and noting loss of an otherwise essential Arg in transmembrane helix IV, framing the complex as atypical relative to canonical orthologs.

   Evidence Computational identification from structural fingerprints and proteomics data of other protists

   PMID:19682605

   Open questions at the time

   • Prediction only, with no experimental validation of ATPTG3 specifically
   • Does not assign ATPTG3 to any structural role
   • No functional consequence of the divergent features tested
3. 2015 Low

   To determine when the ATP synthase complex is required across the parasite life cycle, knockout of the β subunit (a sibling subunit of the same complex, not ATPTG3) showed the complex is dispensable for asexual blood-stage growth but essential for mosquito-stage viability.

   Evidence Genetic knockout of the ATP synthase β subunit in P. berghei with mosquito transmission assays and complementation cross

   PMID:25831536

   Open questions at the time

   • Finding concerns the β subunit, not ATPTG3; relevance is indirect via complex membership
   • ATPTG3 was not genetically manipulated in this study
   • Whether ATPTG3 is individually required for complex assembly or stage-specific function is untested

• Whether ATPTG3 is individually essential, its precise structural position within the dimeric ATP synthase, and its molecular contribution to complex assembly or function remain unresolved.
• No gene disruption or knockdown of ATPTG3 itself has been reported
• No structural placement of ATPTG3 within the complex
• No biochemical characterization of ATPTG3's interactions distinct from bulk complex isolation