Affinage · Plasmodium

PUF1

PF3D7_0518700 · mRNA-binding protein PUF1

Audit flag: identity unverified
Annotated
2026-09-07
7 papers in source corpus 4 papers cited in narrative 6 extracted findings

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

PF3D7_0518700 (PUF1) is a Puf-family RNA-binding protein that acts as a post-transcriptional regulator of sexual differentiation in Plasmodium falciparum gametocytes (PMID:27383769). Its Puf domain has intrinsic, sequence-specific RNA-binding activity, demonstrated by its ability to bind the Nanos-responsive elements of Drosophila hunchback mRNA in both a yeast three-hybrid assay and in vitro with recombinant protein—establishing a conserved Puf-domain binding mechanism (PMID:12409450). PUF1 is expressed preferentially in gametocytes at both the transcript and protein levels, with higher protein abundance in female gametocytes (PMID:12409450, PMID:27383769). Functionally, PUF1 is dispensable for the asexual erythrocytic cycle but required for the maintenance and sexual differentiation of gametocytes: its disruption in P. falciparum causes an ~tenfold reduction in mature gametocytes, accumulation of dead late-stage gametocytes after stage III, and a disproportionate loss of female gametocytes that reverses the sex ratio (PMID:27383769). Consistent with a role in translational control, PUF1 physically associates with an interaction network centered on the CCCH zinc finger protein MD3 in male gametocytes, which includes RNA-binding proteins and translational regulators (PMID:38148574). Species divergence is evident in the loss-of-function phenotype: in the rodent parasite P. berghei, genetic deletion of Puf1 produces no detectable phenotype across the life cycle (PMID:21673790). The specific mRNA targets of PUF1 in the native parasite and its precise regulatory role within the MD3 complex have not been characterized in the available corpus.

Mechanistic history

Synthesis pass · year-by-year structured walk · 5 steps
  1. 2002 Medium

    Whether the Plasmodium Puf domain retained the RNA-binding activity characteristic of the family was unknown; showing it binds a defined element established PUF1 as a bona fide sequence-specific RNA-binding protein.

    Evidence Yeast three-hybrid and in vitro binding of the recombinant Puf domain to Drosophila hunchback NRE

    PMID:12409450

    Open questions at the time
    • Binding shown only to a heterologous (Drosophila) target, not a native Plasmodium mRNA
    • No endogenous PUF1 RNA targets identified
    • No structural model of the domain-RNA interface
  2. 2002 Medium

    The developmental context of PUF1 action was undefined; detecting preferential gametocyte expression pointed to a role in sexual-stage biology rather than asexual growth.

    Evidence Northern blot and RT-PCR across erythrocytic stages

    PMID:12409450 PMID:27383769

    Open questions at the time
    • Transcript-level data does not establish protein abundance or timing
    • Does not resolve which gametocyte sex or stage predominates
  3. 2011 Medium

    Whether PUF1 is essential in vivo was tested by deletion in a tractable rodent model, revealing it is dispensable across the P. berghei life cycle.

    Evidence Targeted gene knockout and full life-cycle phenotypic analysis in P. berghei

    PMID:21673790

    Open questions at the time
    • Negative result may reflect species differences from P. falciparum
    • No molecular readout of gametocyte quality beyond life-cycle progression
    • Does not exclude redundancy with paralogs
  4. 2016 High

    The functional requirement of PUF1 in the human parasite was resolved by disruption, showing it is needed for gametocyte maintenance and female sexual differentiation despite being dispensable asexually.

    Evidence Gene disruption in P. falciparum with gametocytemia, stage progression, and sex-ratio readouts, plus stage-specific protein expression

    PMID:27383769

    Open questions at the time
    • Mechanism connecting RNA binding to female gametocyte survival not defined
    • Direct mRNA targets underlying the phenotype unknown
    • Divergence from the P. berghei null phenotype unexplained
  5. 2023 Medium

    How PUF1 fits into the translational-regulatory machinery was addressed by mapping its interaction network, placing it within an MD3-centered complex of RNA-binding proteins and translational regulators in male gametocytes.

    Evidence BioID proximity labeling and co-immunoprecipitation in P. falciparum male gametocytes

    PMID:38148574

    Open questions at the time
    • PUF1's specific role within the MD3 complex not dissected
    • Interaction defined in male gametocytes while the loss-of-function phenotype is female-biased
    • Direct versus indirect (RNA-bridged) interactions not distinguished

Open questions

Synthesis pass · forward-looking unresolved questions
  • The native mRNA targets of PUF1 and the mechanism by which its RNA-binding activity within the MD3 complex controls female gametocyte differentiation remain undefined.
  • No transcriptome-wide identification of PUF1-bound mRNAs in Plasmodium
  • No demonstration of translational activation or repression by PUF1 on a native target
  • Reconciliation of male-gametocyte complex membership with female-biased loss-of-function phenotype

Mechanism profile

Synthesis pass · controlled-vocabulary classification
Partners
MD3 (CCCH ZINC FINGER PROTEIN) [#5]
Complex memberships
MD3 interaction network in P. falciparum male gametocytes (includes PABP1, ALBA3, eIF4G, NOT1, CITH, ZNF4, MD1, GD1) [#5]

Evidence

Reading pass · 6 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
2002 The Puf domain of PF3D7_0518700 (PfPuf1) binds the Nanos-responsive elements (NRE) in Drosophila hunchback mRNA, as demonstrated both in vivo by yeast three-hybrid system and in vitro by binding assays using bacterially expressed recombinant Puf domain, establishing intrinsic RNA-binding activity of the PfPuf1 Puf domain via a conserved mechanism. Yeast three-hybrid system (in vivo); in vitro RNA-binding assay with recombinant bacterially expressed Puf domain Nucleic acids research Medium 12409450
2002 PF3D7_0518700 (PfPuf1) is preferentially expressed in gametocytes during erythrocytic development, as shown by Northern blot and RT-PCR analysis. Northern blot; RT-PCR Nucleic acids research Medium 12409450 27383769
2011 In P. berghei, genetic deletion of Puf1 produces no detectable phenotype throughout the entire parasite life cycle, including sporozoite stage conversion, indicating that Puf1 is dispensable in vivo in the rodent malaria model. Targeted gene deletion (knockout) in P. berghei; life-cycle phenotypic analysis PloS one Medium 21673790
2016 Disruption of PF3D7_0518700 (PfPuf1) in P. falciparum does not affect the asexual erythrocytic cycle but causes an approximately tenfold decrease in mature gametocytes, with normal morphology before stage III followed by accumulation of dead/dying late-stage gametocytes and a disproportionate loss of female gametocytes resulting in a reversed male-to-female sex ratio, establishing a role for PfPuf1 in maintenance and sexual differentiation of gametocytes, especially female gametocytes. Gene disruption (loss-of-function); gametocytemia quantification; stage-specific morphological analysis; sex-ratio determination Journal of cell science High 27383769
2016 PF3D7_0518700 (PfPuf1) protein is expressed in all gametocyte stages and at higher levels in female gametocytes of P. falciparum, as determined by immunofluorescence/Western analysis in the context of disruption studies. Stage-specific expression analysis in gametocyte-producing cultures; protein-level detection Journal of cell science Medium 27383769
2023 PF3D7_0518700 (PUF1) is identified as part of an interaction network with the CCCH zinc finger protein MD3 in P. falciparum male gametocytes, alongside other RNA-binding proteins (PABP1, ALBA3), translational regulators (eIF4G, NOT1, CITH), and gametocytogenesis regulators (ZNF4, MD1, GD1), as revealed by BioID proximity labeling and co-immunoprecipitation assays. BioID proximity labeling; co-immunoprecipitation Molecular microbiology Medium 38148574

Source papers

Stage 0 corpus · 7 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2011 Transition of Plasmodium sporozoites into liver stage-like forms is regulated by the RNA binding protein Pumilio. PLoS pathogens 70 21625527
2002 The malaria parasite Plasmodium falciparum encodes members of the Puf RNA-binding protein family with conserved RNA binding activity. Nucleic acids research 67 12409450
2011 The Puf-family RNA-binding protein Puf2 controls sporozoite conversion to liver stages in the malaria parasite. PloS one 59 21673790
2004 Characterization of PfPuf2, member of the Puf family RNA-binding proteins from the malaria parasite Plasmodium falciparum. DNA and cell biology 29 15585133
2016 The RNA-binding protein Puf1 functions in the maintenance of gametocytes in Plasmodium falciparum. Journal of cell science 28 27383769
2023 The Plasmodium falciparum CCCH zinc finger protein MD3 regulates male gametocytogenesis through its interaction with RNA-binding proteins. Molecular microbiology 8 38148574
2026 Molecular mechanisms involved in Plasmodium gametocytogenesis. Frontiers in microbiology 0 41716278