SYN13

PF3D7_1104100 (SYN13) is a Qa-SNARE/syntaxin-family protein of Plasmodium falciparum known only from genome-wide bioinformatic surveys, which catalogued it among the SNARE-like proteins of the parasite and placed it within a P. falciparum-specific syntaxin-like subfamily (PMID:17240462); subsequent genome mining classified it as one of seven parasite Qa-SNAREs (PMID:19103232). No direct experiment in the available corpus has established the subcellular localization, binding partners, enzymatic activity, or cellular function of SYN13 itself: in each survey, direct localization was reported only for other family members (PfSyn5p, PfSec22p, PfStx1), not SYN13 (PMID:17240462, PMID:19103232). Broader functional studies of the P. falciparum SNARE complement characterized Stx12 and Stx16/Stx6 in trafficking and inner membrane complex biogenesis, but did not experimentally interrogate SYN13 (PMID:33082261). Beyond its membership in the syntaxin/Qa-SNARE family, no mechanistic detail specific to PF3D7_1104100 has been characterized in the available corpus.

1. 2006 Low

   Establishing the parasite's SNARE repertoire was the first step toward understanding its membrane trafficking; this survey placed SYN13 on the map as a syntaxin-like protein within a P. falciparum-specific subfamily.

   Evidence Bioinformatic and phylogenetic analysis of the P. falciparum genome, with GFP-tagging of select (non-SYN13) family members

   PMID:17240462

   Open questions at the time

   • Identification is computational only; no direct experiment was performed on SYN13/PF3D7_1104100
   • Subcellular localization of SYN13 was not reported
   • No binding partners or function assigned
2. 2008 Low

   Refining the Qa-SNARE subset and predicting intracellular locations aimed to assign each syntaxin to a trafficking step, but SYN13's predicted location was never experimentally tested.

   Evidence Genome mining, sequence alignment, and gene-structure confirmation; direct localization confirmed only for PfStx1

   PMID:19103232

   Open questions at the time

   • SYN13 localization was predicted computationally, not validated
   • No cognate SNARE partners identified for SYN13
   • No functional or knockdown data for SYN13
3. 2020 Low

   Functional dissection of individual parasite SNAREs began to link specific syntaxins to defined trafficking routes, yet SYN13 remained only a listed member of the assessed complement rather than an experimental subject.

   Evidence Conditional knockdown, co-immunoprecipitation with SEC1/Munc18 tethering factors, and fluorescence microscopy of Stx12 and Stx16/Stx6 (not SYN13)

   PMID:33082261

   Open questions at the time

   • No experiment in the study addresses SYN13/PF3D7_1104100 directly
   • SYN13 trafficking role, partners, and essentiality remain untested
4. 2026 Low

   A syntaxin-5-like parasite protein ('PfSyn5') was characterized as a mosquito midgut-factor binding partner and transmission-blocking antibody target, but the abstract does not map 'PfSyn5' to PF3D7_1104100, so this cannot be attributed to SYN13.

   Evidence Biochemical interaction pulldown/binding assays plus infection assays with recombinant protein and blocking antibodies (preprint)

   PMID:42146686

   Open questions at the time

   • Gene identity of 'PfSyn5' relative to PF3D7_1104100 is not confirmed; attribution to SYN13 is uncertain
   • Single-lab preprint not independently confirmed
   • No direct evidence that SYN13 mediates the reported interaction or transmission phenotype

• The core mechanistic questions for SYN13 remain entirely open: its subcellular localization, cognate SNARE and Munc18/SEC1 partners, the membrane-fusion step it catalyzes, and its role in parasite biology are all uncharacterized in the available corpus.
• No experimental localization of SYN13
• No identified binding partners or complex membership for SYN13 specifically
• No knockdown/knockout phenotype defining its cellular function