SLP

SLP (PF3D7_0710000) is an Sfi1-like, centrin-interacting protein of the Plasmodium falciparum centriolar plaque that couples the extranuclear centrosome-equivalent to intranuclear microtubule regulation during asexual blood-stage proliferation (PMID:37130129). It localizes to the extranuclear compartment of the centriolar plaque, where it interacts with centrins (PMID:37130129). Conditional depletion of SLP disrupts intranuclear tubulin homeostasis, driving increased intranuclear tubulin abundance, excess microtubules, and aberrant mitotic spindles, which delay or prevent mitotic spindle extension without significantly impairing DNA replication (PMID:37130129); the functional consequence is a growth delay and reduced daughter cell formation during schizogony (PMID:37130129). Beyond this single-study characterization in P. falciparum, no further mechanistic detail—including the structural basis of centrin binding or how an extranuclear protein controls intranuclear tubulin—has been characterized in the available corpus.

1. 2023 High

   Establishing that PF3D7_0710000 is a bona fide centriolar plaque component answered where this uncharacterized protein acts and identified its physical partner within the centrosome-equivalent.

   Evidence Conditional knockdown, live-cell imaging, and co-immunoprecipitation/localization in P. falciparum showing extranuclear centriolar plaque localization and centrin interaction

   PMID:37130129

   Open questions at the time

   • Structural basis and stoichiometry of the SLP–centrin interaction not defined
   • Whether SLP has activities beyond scaffolding at the plaque is unknown
2. 2023 High

   Conditional knockdown answered whether SLP is functionally required, showing it contributes to asexual proliferation rather than being dispensable.

   Evidence Inducible conditional knockdown with growth and daughter-cell-count readouts in P. falciparum blood stages

   PMID:37130129

   Open questions at the time

   • Whether SLP is essential or only rate-limiting is not resolved
   • Role in stages other than asexual blood-stage schizogony untested
3. 2023 High

   Quantifying the depletion phenotype answered what cellular process SLP controls, linking this extranuclear plaque protein to intranuclear tubulin and microtubule homeostasis.

   Evidence Conditional knockdown with fluorescence microscopy quantifying intranuclear tubulin signal and spindle morphology in P. falciparum

   PMID:37130129

   Open questions at the time

   • Molecular mechanism by which an extranuclear protein influences intranuclear tubulin is unknown
   • Whether the effect is direct or via a downstream mediator not established
4. 2023 Medium

   Time-lapse imaging placed SLP in the mitotic pathway, showing it acts upstream of spindle extension but not of DNA replication.

   Evidence Time-lapse live-cell microscopy following conditional knockdown in P. falciparum

   PMID:37130129

   Open questions at the time

   • Pathway placement rests on a single imaging method
   • How excess microtubules mechanically or biochemically block spindle extension is unresolved

• It remains unknown how SLP, an extranuclear centriolar plaque protein, mechanistically restrains intranuclear tubulin polymerization and what molecular intermediary bridges the two compartments.
• No biochemical mechanism connecting SLP to intranuclear tubulin identified
• No structural model of SLP or its complex available
• Function outside asexual blood stages uncharacterized