DYN1

DYN1 (PF3D7_1145400) is a Plasmodium falciparum dynamin-like GTPase that functions in membrane dynamics and endocytic trafficking during the asexual erythrocytic cycle (PMID:15240099, PMID:19719972). The protein contains a conserved N-terminal tripartite GTPase domain, a coiled-coil region, and a C-terminal domain, is expressed specifically in the mature asexual sub-stage, and localizes to the endoplasmic reticulum and to multiple membrane structures and ~60–100 nm vesicles within the parasite, at its surface, and in the erythrocyte cytoplasm (PMID:15240099). Its recombinant GTPase domain is catalytically active and inhibited in vitro by the dynamin inhibitor dynasore; pharmacological inhibition reduces hemoglobin uptake and hemozoin accumulation and arrests growth, implicating DYN1 in the hemoglobin endocytosis pathway, consistent with the growth defect caused by dsRNA targeting its C-terminus (PMID:15240099, PMID:19719972). DYN1 transcription is regulated by the host hormone melatonin through a PfPK7-dependent pathway linked to mitochondrial fission (PMID:29480948). Beyond these findings, its direct binding partners and role in specific trafficking routes remain uncharacterized in the available corpus; proximity labeling has only placed it as a candidate near the Golgi–microneme axis (PMID:41125830).

1. 2004 Medium

   Establishing that P. falciparum encodes a dynamin-like GTPase and that it is essential answered whether the parasite possesses its own membrane-remodeling machinery of this class and whether it matters for blood-stage survival.

   Evidence cDNA cloning, Western blot, immunofluorescence co-localization with the ER marker PfGRP, and dsRNA knockdown growth-inhibition assay in Dd2 asexual stages

   PMID:15240099

   Open questions at the time

   • No in vitro GTPase activity demonstrated for DYN1 in this study
   • dsRNA knockdown lacks single-gene specificity controls
   • Exact membrane structures and vesicle identity not molecularly defined
2. 2009 Medium

   Demonstrating catalytic GTPase activity and a functional link to hemoglobin uptake moved DYN1 from a predicted dynamin-like protein to an enzyme implicated in a specific endocytic process.

   Evidence Recombinant GTPase-domain activity assay, dynasore pharmacological inhibition, FITC-dextran uptake, and transmission electron microscopy in parasite cultures

   PMID:19719972

   Open questions at the time

   • Dynasore also inhibits DYN2, so effects cannot be attributed to DYN1 alone
   • No direct genetic loss-of-function tied to the hemoglobin-uptake phenotype
   • Mechanistic role of DYN1 at the endocytic membrane not resolved
3. 2018 Medium

   Placing DYN1 transcription downstream of PfPK7 in melatonin signaling connected the protein to host-hormone-triggered mitochondrial fission, positing a regulatory input onto DYN1 expression.

   Evidence mRNA expression analysis, PfPK7 knockout epistasis, MitoTracker morphology, oxygen consumption, and mitochondria-targeted GFP

   PMID:29480948

   Open questions at the time

   • Regulation shown at mRNA level, not DYN1 protein or activity
   • Direct role of DYN1 protein in mitochondrial fission not demonstrated
   • Whether PfPK7 acts on DYN1 directly or indirectly is unknown
4. 2025 Low

   Proximity labeling raised the possibility that DYN1 acts in Golgi-to-microneme vesicular trafficking by placing it near the PIP-binding protein PfPX2.

   Evidence Proximity labeling (BioID-type) mass spectrometry identifying DYN1 as a candidate proximal interactor of PfPX2

   PMID:41125830

   Open questions at the time

   • Single indirect method with no reciprocal or direct interaction validation
   • DYN1 role in Golgi–microneme trafficking not functionally tested
   • Proximity does not establish physical or functional partnership

• Whether DYN1 physically assembles into a defined complex, what membranes it directly remodels, and how its distinct roles (hemoglobin uptake, ER/vesicle association, mitochondrial fission signaling, Golgi–microneme axis) are mechanistically integrated remain open.
• No validated direct binding partners identified
• No structural model of the assembled/oligomeric protein
• Direct genetic dissection separating DYN1 from DYN2 functions lacking