NOT1

PF3D7_1417200 (NOT1) is the canonical scaffold subunit of the Plasmodium CAF1/CCR4/NOT complex, a post-transcriptional regulatory machine, and in Plasmodium the NOT1 scaffold is duplicated into two paralogues: PF3D7_1417200 and a transmission-dedicated paralogue, NOT1-G (PMID:34673764). The distinct role of PF3D7_1417200 is defined chiefly by its behaviour across the host-to-vector transmission event: in P. yoelii, proximity proteomics shows that DOZI (a DDX6 orthologue) exchanges its interaction from NOT1-G in female gametocytes to canonical NOT1 in zygotes, positioning PF3D7_1417200 as a molecular trigger for the release of mRNAs from translational repression following fertilization (PMID:38352447, PMID:39777415). Beyond its identification as the scaffold component of the PfCaf1-CCR4-NOT complex (PMID:26525978) and this DOZI-exchange model, no direct biochemical or structural characterization of PF3D7_1417200 itself has been established in the available corpus; much of its mechanistic role is inferred from studies of its paralogue and interacting partners rather than tested directly on PF3D7_1417200.

1. 2015 Low

   Before any experimental work, it was unknown whether Plasmodium encodes a NOT1 scaffold; comparative interactome analysis assigned PF3D7_1417200 to the conserved Caf1-CCR4-NOT complex, establishing a candidate post-transcriptional regulatory role.

   Evidence Bioinformatic genome analysis and comparative protein-protein interaction network reconstruction in P. falciparum

   PMID:26525978

   Open questions at the time

   • Computational prediction only, with no direct experimental validation of PF3D7_1417200
   • No demonstration of physical association with complex members
   • No functional assay of the predicted scaffold activity
2. 2021 Medium

   It was unknown how one NOT1 scaffold could serve both housekeeping and transmission needs; discovery of a paralogue duplication showed that a dedicated NOT1-G handles essential transmission functions while PF3D7_1417200 represents the canonical, distinct paralogue.

   Evidence Genetic deletion of not1-g, comparative transcriptomics, live imaging, and domain-deletion analysis in P. yoelii

   PMID:34673764

   Open questions at the time

   • Mechanistic detail about PF3D7_1417200 itself is inferred from the paralogue knockout rather than directly tested
   • No phenotype from direct perturbation of canonical NOT1
   • Division of labour between the two paralogues within the complex not biochemically resolved
3. 2025 Medium

   The functional trigger distinguishing PF3D7_1417200 from its paralogue was unresolved; proximity proteomics showed that DOZI switches from NOT1-G in female gametocytes to canonical NOT1 in zygotes, providing a model in which PF3D7_1417200 mediates release of repressed mRNAs after transmission.

   Evidence TurboID proximity proteomics (DIA-MS) of the DOZI/CITH/ALBA complex across gametocyte-to-zygote transition, with expansion and structured-illumination microscopy cross-validation in P. yoelii (peer-reviewed following a 2024 preprint)

   PMID:38352447 PMID:39777415

   Open questions at the time

   • Canonical NOT1 interaction established by proximity labelling rather than direct co-IP or reciprocal validation
   • Single lab, single study
   • The mRNA-release model is inferred from the interaction switch, not directly demonstrated by measuring translational activation

• Direct biochemical, structural, and functional characterization of PF3D7_1417200 as a scaffold — its assembled complex composition, deadenylation activity, and the mechanism by which the DOZI switch releases translational repression — remains unestablished.
• No direct co-IP or reconstitution confirming PF3D7_1417200 scaffold interactions
• No structural model of PF3D7_1417200 or its subunit-binding surfaces
• No loss-of-function phenotype from direct perturbation of PF3D7_1417200