Affinage

SNAPIN

SNARE-associated protein Snapin · UniProt O95295

Length
136 aa
Mass
14.9 kDa
Annotated
2026-06-10
68 papers in source corpus 39 papers cited in narrative 38 extracted findings
Cross-family judge vs UniProt: Affinage preferred faithfulness: 6/6 claims corpus-supported (100%)

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

Snapin is a ubiquitously expressed coiled-coil adaptor that functions at the interface of regulated membrane fusion and dynein-driven retrograde transport (PMID:10195194, PMID:12877659, PMID:21233602, PMID:20920785). At the presynaptic terminal it binds SNAP-25 (and the non-neuronal homologue SNAP-23) within the SNARE complex, stabilising the coupling of synaptotagmin-1 to the assembled SNARE and thereby priming vesicles for synchronous Ca2+-dependent exocytosis; loss of Snapin desynchronises vesicle fusion and shrinks the readily releasable pool, defects rescued by re-expression (PMID:10195194, PMID:16280592, PMID:19217378). This priming activity is bidirectionally tuned by phosphorylation: PKA modification at Ser50 strengthens Snapin–SNAP-25 and synaptotagmin–SNARE binding to expand the release-competent vesicle population, while the phosphomimetic state remodels Snapin's helical structure and oligomeric assembly toward the high-affinity SNARE-binding form (PMID:11283605, PMID:22471585). Independently, Snapin is a stable subunit of the BLOC-1 complex, co-assembling with dysbindin, pallidin, muted and cappuccino, an interaction that reciprocally stabilises Snapin protein levels (PMID:15102850, PMID:16980328, PMID:18774265). As a dynein motor adaptor, Snapin recruits dynein to late endosomes to drive retrograde axonal transport of TrkB/BDNF signalling endosomes and of BACE1 to lysosomes, coordinating late endosomal–lysosomal trafficking, lysosomal acidification, autophagy–lysosomal homeostasis, and neuronal viability (PMID:21233602, PMID:20920785, PMID:22840395, PMID:24373968, PMID:27929705). Through this trafficking and SNARE adaptor activity Snapin engages a broad partner set—Exo70, RyR, ACVI/AC6, DAT, Cav1.3, and TLR8-bearing endosomes—to modulate GLUT4-dependent glucose uptake, Ca2+ signalling, cAMP synthesis, dopamine reuptake, and endosomal innate-immune sensing (PMID:16723744, PMID:17947242, PMID:21986494, PMID:27915047, PMID:28923824, PMID:28905875).

Mechanistic history

Synthesis pass · year-by-year structured walk · 23 steps
  1. 1999 High

    Established Snapin as a SNARE-associated protein and its first functional role, answering whether a SNAP-25 binding partner could gate neurotransmitter release.

    Evidence Yeast two-hybrid, pulldown, peptide microinjection into SCG neurons with electrophysiology

    PMID:10195194

    Open questions at the time
    • Precise stoichiometry within the SNARE complex not resolved
    • Did not address how Snapin binding is regulated
  2. 2001 High

    Identified PKA phosphorylation at Ser50 as the regulatory switch increasing Snapin–SNAP-25 affinity and synaptotagmin coupling, linking cAMP signalling to vesicle priming.

    Evidence Site-directed mutagenesis (S50D/S50A), in vitro kinase assay, chromaffin cell capacitance, hippocampal slice phosphorylation

    PMID:11283605

    Open questions at the time
    • Structural basis of phosphorylation-enhanced binding not yet defined
    • Other kinases not yet examined
  3. 2003 Medium

    Extended Snapin beyond neurons by showing it binds SNAP-23 and forms ternary complexes with syntaxin-4, establishing a general role in non-neuronal SNARE fusion.

    Evidence Pulldown, co-IP, subcellular fractionation, ternary complex reconstitution in adipocytes

    PMID:12877659

    Open questions at the time
    • Functional consequence in non-neuronal exocytosis not yet tested here
    • Single-lab biochemistry
  4. 2004 High

    Defined Snapin as a stable BLOC-1 subunit whose levels depend on complex assembly, connecting it to biogenesis of lysosome-related organelles.

    Evidence Reciprocal co-IP, size-exclusion co-fractionation, pallid mouse immunoblotting, yeast two-hybrid network

    PMID:15102850

    Open questions at the time
    • How BLOC-1 membership relates to SNARE/dynein roles unresolved
    • Cargo specificity of BLOC-1-associated Snapin not defined
  5. 2004 High

    Resolved the cellular consequence of Ser50 phosphorylation on synaptic dynamics, showing it lowers RRP size while raising per-vesicle release probability.

    Evidence S50D/S50A overexpression with patch-clamp and Sp-cAMPS dialysis in hippocampal neurons

    PMID:15269257

    Open questions at the time
    • Reconciliation with chromaffin-cell results (increased release-competent vesicles) not fully resolved
  6. 2005 High

    Genetic knockout confirmed Snapin is required in vivo for synaptotagmin–SNARE coupling and Ca2+-dependent exocytosis, with full rescue establishing causality.

    Evidence Snapin KO mice, co-IP, chromaffin cell capacitance, LDV purification, re-expression rescue

    PMID:16280592

    Open questions at the time
    • Did not distinguish priming from fusion-synchrony functions
  7. 2005 Medium

    Demonstrated Snapin's coiled-coil interactome extends to cypin and EBAG9, linking it to dendrite patterning and secretion control via competition and phosphorylation regulation.

    Evidence Yeast two-hybrid, co-IP, microtubule assembly assay, neuronal morphometry; NPY secretion assay in PC12 cells

    PMID:15635093 PMID:16120643

    Open questions at the time
    • Physiological significance of cypin competition in vivo unclear
    • EBAG9-controlled kinase not identified
  8. 2006 Medium

    Mapped multiple membrane and channel partners (dysbindin, RyR, ACVI) and the CK1δ kinase to shared C-terminal and Ser50 regions, revealing competitive partner exchange on Snapin.

    Evidence Co-IP, immunoEM, peptide/domain mapping, ryanodine binding assay, in vitro kinase assay, adenylyl cyclase activity

    PMID:15319443 PMID:16723744 PMID:16980328 PMID:17101137

    Open questions at the time
    • Overlapping binding sites imply competition not directly quantified for all partners
    • Functional CK1δ phosphosite not yet defined
  9. 2007 Medium

    Connected Snapin to peripheral transport functions—GLUT4/glucose uptake via Exo70, α1A-AR/TRPC6 Ca2+ influx, and UT-A1 urea transport—through competitive partner binding to its C-terminus.

    Evidence Co-IP, domain mapping, siRNA in adipocytes, Ca2+ imaging in PC12, Xenopus oocyte transport assays

    PMID:17684020 PMID:17702749 PMID:17947242

    Open questions at the time
    • Whether SNARE versus Exo70 binding is dynamically regulated in vivo unclear
    • Single-lab functional assays
  10. 2009 High

    Separated Snapin's dual presynaptic roles: dimerization fine-tunes fusion synchrony while monomer–SNARE interactions govern priming, and identified late-endosomal SNARE association.

    Evidence Snapin-deficient neurons, patch-clamp, C66A dimerization mutant rescue; co-IP and KO phenotype with syntaxin-8/Vti1b

    PMID:19217378 PMID:19335339

    Open questions at the time
    • Structural determinants of dimer versus oligomer states not solved
    • Link between late-endosomal SNARE role and synaptic role unresolved at this stage
  11. 2010 High

    Defined Snapin as a dynein adaptor recruiting motor to late endosomes, establishing its central role in retrograde trafficking and autophagy–lysosomal homeostasis required for neuronal viability.

    Evidence Snapin KO mice, live imaging, Snapin–dynein co-IP, autolysosome clearance assay, transgenic rescue

    PMID:20920785 PMID:21233602

    Open questions at the time
    • Molecular interface between Snapin and dynein not structurally defined
    • How adaptor versus SNARE roles are partitioned unclear
  12. 2011 Medium

    Tied Snapin phosphorylation to systemic physiology, showing PKA-dependent Snapin drives incretin-potentiated insulin secretion and that AC6–Snapin–SNAP-25 complexes restrain neurite outgrowth.

    Evidence PKA assays, co-IP in islets, phosphomimetic rescue in diabetic islets; mutant/KO neurite assays

    PMID:21356520 PMID:21986494

    Open questions at the time
    • Direct demonstration of the insulin vesicle SNARE complex composition limited
    • Single-lab functional readouts
  13. 2012 High

    Established Snapin as the adaptor coupling dynein to TrkB signalling endosomes and Atg14L-dependent endosome maturation, and showed its requirement for presynaptic homeostatic plasticity with dysbindin.

    Evidence Snapin KO microfluidic cortical cultures, live TrkB imaging, dynein-disrupting mutants; Atg14L co-IP/rescue; Drosophila snapin LOF with epistasis

    PMID:22723711 PMID:22797916 PMID:22840395

    Open questions at the time
    • Cross-species mechanism of homeostasis not fully unified
    • Whether BLOC-1 and dynein-adaptor functions act in the same pathway here unresolved
  14. 2012 Medium

    Provided biophysical basis for phosphorylation control, showing S50D destabilises helix and shifts oligomeric state toward dimers with strongest SNARE binding.

    Evidence CD spectroscopy, fluorescence anisotropy, thermal stability, SEC, in vitro SNARE pulldown of recombinant protein

    PMID:22471585

    Open questions at the time
    • No high-resolution structure or coordinates
    • In vitro state may not capture in-cell assembly
  15. 2013 High

    Showed LRRK2 phosphorylation at Thr117 antagonistically weakens SNARE binding and exocytosis, and that Snapin-dynein adaptor activity drives BACE1 retrograde clearance limiting amyloidogenic APP processing.

    Evidence In vitro kinase assay, T117D mutant electrophysiology; Snapin KO neurons, BACE1 transport imaging, APP processing readout, rescue

    PMID:23949442 PMID:24373968

    Open questions at the time
    • Whether LRRK2 phosphorylation also affects dynein-adaptor function untested
    • Disease-relevant in vivo kinase activity not directly measured
  16. 2013 Medium

    Invertebrate genetics positioned Snapin upstream of synaptotagmin in vesicle docking/priming, independent of Ca2+-sensing function.

    Evidence C. elegans snpn-1 LOF, NMJ electrophysiology, EM docked-vesicle counts, snt-1;snpn-1 epistasis

    PMID:23469084

    Open questions at the time
    • Mechanism of docking stabilisation not biochemically resolved
    • Single model system
  17. 2015 High

    Unified Snapin's transport and SNARE roles, showing dynein-driven late-endosome transport sets SV pool size while BLOC-1/AP-3 sorting via dysbindin tunes Ca2+-sensitivity of release.

    Evidence Snapin KO neurons, dynein-binding mutants, SV-targeted Ca2+ sensor, live imaging, electrophysiology

    PMID:26108535

    Open questions at the time
    • How the two activities are switched/coordinated molecularly unresolved
  18. 2016 Medium

    Defined Snapin's requirement for lysosomal acidification and autophagosome maturation, and revealed channel/trafficking control of Cav1.3 and endosomal TLR8-mediated innate immunity.

    Evidence siRNA in macrophages with ratiometric lysosomal pH and cathepsin D assays; Cav1.3 ubiquitination/patch-clamp; TLR8 signalling and HIV-1 trans-infection assays in DCs

    PMID:27915047 PMID:27929705 PMID:28923824

    Open questions at the time
    • Mechanism of proton leak control not molecularly defined
    • Whether TLR8 effect is via the same dynein-adaptor pathway untested
  19. 2017 Medium

    Established direct DAT regulation by Snapin, linking it to dopamine reuptake and amphetamine response in vivo.

    Evidence Two-hybrid, co-IP, DAT uptake assay, in vivo Snapin KD with locomotor testing, interaction model

    PMID:28905875

    Open questions at the time
    • Interaction interface modelled but not structurally validated
    • Mechanism of DAT downregulation (trafficking vs degradation) not fully resolved
  20. 2021 Medium

    Identified p38α-MAPK phosphorylation at Ser112 as a regulator of BACE1 retrograde transport, adding a kinase input controlling Snapin's lysosomal-targeting adaptor function.

    Evidence p38α neuron-specific KO, in vitro kinase assay with MS, S112A mutagenesis, BACE1 transport/activity assays

    PMID:34118085

    Open questions at the time
    • Whether S112 phosphorylation alters dynein binding directly untested
    • Single-lab functional rescue
  21. 2022 Medium

    Showed DYRK3 phosphorylation at Thr14 enhances Snapin–dynein and Snapin–synaptotagmin binding, promoting mitochondrial retrograde transport and SV recycling pool size.

    Evidence Yeast two-hybrid, in vitro kinase assay, T14 mutagenesis, co-IP, live mitochondrial transport imaging, electrophysiology

    PMID:36585413

    Open questions at the time
    • Interplay between the multiple Snapin phosphosites not addressed
    • In vivo significance for neuronal survival not directly tested
  22. 2025 Medium

    Extended Snapin biology to disease-relevant lysosomal and metabolic axes: CK1δ hyperphosphorylation disrupts lysosomal positioning, and Snapin–CBS binding controls H2S-dependent cathepsin D maturation and PANoptosis.

    Evidence Vpr/CK1δ-inhibitor lysosomal assays in neurons; mTBI mouse model with Snapin KD, Snapin–CBS co-IP, biotin-switch S-sulfhydration, behavior

    PMID:41558604 PMID:41567242

    Open questions at the time
    • Functional CK1δ phosphosite on Snapin not mapped
    • CBS interaction interface only docked, not structurally resolved
  23. 2025 Low

    Linked Snapin to redox/ferroptosis control in cancer via lysosomal KEAP1 degradation and NRF2/GPX4 stabilisation.

    Evidence SNAPIN overexpression/KD in HCC cells, Snapin–KEAP1 co-IP, lysosomal degradation inhibition, NRF2/GPX4 immunoblot, ferroptosis assay

    PMID:41190709

    Open questions at the time
    • Single co-IP and inhibitor experiment without reciprocal validation
    • Direct binding interface and selectivity not established
    • Not independently confirmed

Open questions

Synthesis pass · forward-looking unresolved questions
  • How Snapin's distinct activities—SNARE priming, BLOC-1 membership, and dynein-adaptor transport—are molecularly partitioned and switched by its multiple phosphosites remains unresolved, and no high-resolution structure of Snapin or its complexes exists.
  • No experimental structure of Snapin or its dynein/SNARE complexes
  • Crosstalk among S50, T117, S112, T14, and CK1δ phosphorylation events undefined
  • Mechanism partitioning adaptor versus SNARE-priming roles unknown

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0060090 molecular adaptor activity 3 GO:0098772 molecular function regulator activity 3 GO:0008092 cytoskeletal protein binding 2
Localization
GO:0005768 endosome 3 GO:0005764 lysosome 2 GO:0005829 cytosol 2 GO:0031410 cytoplasmic vesicle 2 GO:0005794 Golgi apparatus 1
Pathway
R-HSA-112316 Neuronal System 3 R-HSA-162582 Signal Transduction 3 R-HSA-5653656 Vesicle-mediated transport 3 R-HSA-9612973 Autophagy 3 R-HSA-1852241 Organelle biogenesis and maintenance 1
Complex memberships
BLOC-1SNARE complex

Evidence

Reading pass · 38 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
1999 Snapin directly binds SNAP-25 and associates with the SNARE complex; it is enriched in neurons and localized on synaptic vesicle membranes. The C-terminal fragment of Snapin blocks the association of the SNARE complex with synaptotagmin, and introduction of Snapin-CT into presynaptic neurons reversibly inhibited synaptic transmission. Yeast two-hybrid, pulldown, co-immunoprecipitation, peptide microinjection into SCG neurons, electrophysiology Nature neuroscience High 10195194
2001 PKA phosphorylates Snapin at serine 50. Phosphorylation (or S50D phosphomimetic mutation) significantly increases Snapin binding to SNAP-25 and enhances association of synaptotagmin with the SNARE complex. In adrenal chromaffin cells, S50D overexpression increases the number of release-competent vesicles. In vivo, cAMP analogue treatment of hippocampal slices induces Snapin phosphorylation and enhances both Snapin–SNAP-25 and synaptotagmin–SNARE interactions. Site-directed mutagenesis (S50D, S50A), in vitro kinase assay, co-immunoprecipitation, patch-clamp capacitance measurements in chromaffin cells, rat hippocampal slice experiments Nature cell biology High 11283605
2003 Snapin is expressed ubiquitously (not brain-specific) and interacts with SNAP-23, the widely expressed SNAP-25 homologue; the C-terminal helical domain of Snapin contains the SNAP-23-binding site. Snapin can form a ternary complex with SNAP-23 and syntaxin-4, indicating a role in non-neuronal SNARE complexes. Subcellular fractionation shows Snapin exists in both cytosolic and peripheral membrane-bound pools in adipocytes. Protein–protein interaction assays (pulldown, co-immunoprecipitation), subcellular fractionation, GFP fusion overexpression, ternary complex reconstitution The Biochemical journal Medium 12877659
2004 Snapin is a subunit of BLOC-1 (biogenesis of lysosome-related organelles complex-1). Snapin co-immunoprecipitates and co-fractionates with all known BLOC-1 subunits (Pallidin, Muted, Cappuccino, Dysbindin). In pallid mouse cells, steady-state Snapin levels are significantly reduced secondary to Pallidin mutation, consistent with assembly-dependent stability. Yeast two-hybrid analysis reveals a network of binary interactions among BLOC-1 subunits. Co-immunoprecipitation, size-exclusion chromatography, immunoblotting in pallid mouse cells, yeast two-hybrid The Journal of biological chemistry High 15102850
2004 Snapin interacts with the N-terminus (residues 1–86) of type VI adenylyl cyclase (ACVI), with the interaction domain on Snapin mapped to residues 33–51. Snapin expression specifically eliminates PKC-mediated suppression of ACVI activity without affecting PKA- or calcium-mediated regulation. This effect requires direct interaction: a Snapin(Δ33–51) mutant that cannot bind ACVI fails to reverse PKC inhibition. Yeast two-hybrid (bait: ACVI N-terminus), co-immunoprecipitation, mutational analysis, adenylyl cyclase activity assay, co-localization in hippocampal neurons The Journal of biological chemistry Medium 15319443
2004 PKA-dependent phosphorylation of Snapin (S50D mimetic) in hippocampal neurons decreases readily releasable vesicle pool size, increases release probability of individual vesicles, and increases depression rate during high-frequency stimulation. The non-phosphorylatable S50A mutant does not alter pool size or release probability. Dialysis of Sp-cAMPS also leads to increased synaptic depression in cells overexpressing wild-type Snapin. Overexpression of S50D/S50A mutants in hippocampal neurons, whole-cell patch-clamp electrophysiology, Sp-cAMPS dialysis The Journal of neuroscience High 15269257
2005 Snapin knock-out mice show impaired association of synaptotagmin-1 with SNAP-25 in brain homogenates. In embryonic chromaffin cells, absence of Snapin significantly reduces calcium-dependent exocytosis by decreasing the number of vesicles in releasable pools. Snapin is enriched in purified large dense-core vesicles and associates with synaptotagmin-1. Overexpression of Snapin fully rescues the exocytosis defect in mutant cells. Snapin knock-out mice, co-immunoprecipitation, patch-clamp capacitance measurements, LDV purification, rescue by Snapin re-expression The Journal of neuroscience High 16280592
2005 Snapin binds cypin via its C-terminal coiled-coil domain (H2); this interaction requires cypin's CRMP homology domain (the same site where tubulin binds). Snapin competes with tubulin for binding to cypin, resulting in decreased microtubule assembly. Overexpression of Snapin in hippocampal neurons decreases primary dendrite number and increases branching probability, indicating Snapin regulates dendrite patterning by modulating cypin-promoted microtubule assembly. Yeast two-hybrid, affinity chromatography, co-immunoprecipitation, in vitro microtubule assembly assay, overexpression in primary hippocampal neurons, morphometric analysis Molecular biology of the cell Medium 16120643
2005 EBAG9 interacts with Snapin (yeast two-hybrid confirmed). EBAG9–Snapin interaction inhibits regulated secretion of neuropeptide Y from PC12 cells. Mechanistically, EBAG9 decreases phosphorylation of Snapin, which in turn reduces Snapin's association with SNAP-25 and SNAP-23. Yeast two-hybrid, co-immunoprecipitation, neuropeptide Y secretion assay in PC12 cells, phosphorylation analysis Molecular biology of the cell Medium 15635093
2006 Dysbindin-1 binds Snapin in vitro and in mouse/human brain; both proteins are concentrated in synaptic vesicle membrane fractions. Immunoelectron microscopy localises dysbindin-1 to synaptic vesicles of glutamatergic axospinous terminals and to postsynaptic densities and microtubules. A 30-residue peptide in dysbindin (residues 90–119) mediates interaction with Snapin, and Snapin is destabilised in dysbindin-null (sandy) mice. Co-immunoprecipitation, tissue fractionation, immunoelectron microscopy, peptide mapping, immunoblotting in sdy mice Human molecular genetics High 16980328 18774265
2006 Snapin interacts with ryanodine receptor 2 (RyR2) via a 170-residue cytosolic loop (RyR2 residues 4596–4765); this interaction is conserved across RyR1, RyR2, and RyR3. The Snapin–RyR1 association sensitises the channel to Ca2+ activation in ryanodine-binding studies. The ryanodine receptor and SNAP-25 share an overlapping binding site on Snapin's C-terminus. Pulldown with peptide fragments, co-immunoprecipitation with native RyR, [3H]ryanodine binding assay, deletion analysis, competition experiment Journal of cell science Medium 16723744
2006 CK1δ interacts with Snapin (yeast two-hybrid, co-immunoprecipitation) and phosphorylates Snapin in vitro. Both proteins co-localise in the perinuclear region, where Snapin associates with Golgi apparatus membranes. Yeast two-hybrid, co-immunoprecipitation, in vitro kinase assay, co-localization by immunofluorescence FEBS letters Medium 17101137
2007 Snapin interacts with Exo70 subunit of the exocyst via an N-terminal coiled-coil domain in Exo70 and the C-terminal helical region of Snapin. Exo70 competes with SNAP-23 for Snapin binding. RNAi-mediated depletion of Snapin in adipocytes inhibits insulin-stimulated glucose uptake, implicating Snapin in GLUT4 trafficking. Co-immunoprecipitation, pulldown assays, domain mapping, Snapin siRNA knockdown in adipocytes, glucose uptake assay The Journal of biological chemistry Medium 17947242
2007 Snapin interacts with the C-terminus of alpha1A-adrenoceptor (α1A-AR) and co-immunoprecipitates with TRPC6 and α1A-AR. Snapin co-transfection augments α1A-AR-stimulated sustained Ca2+ influx via receptor-operated channels; disrupting the Snapin-binding domain or Snapin siRNA knockdown attenuates this effect. α1A-AR activation increases Snapin–TRPC6 interaction and recruits TRPC6 to the cell surface. Yeast two-hybrid (identified interaction), co-immunoprecipitation, siRNA knockdown, intracellular Ca2+ measurements, cell-surface TRPC6 assay in PC12 cells The Journal of biological chemistry Medium 17684020
2007 Snapin interacts with the UT-A1 urea transporter intracellular loop (residues 409–594); the C-terminal coiled-coil domain (H2) of Snapin is required. Co-injection of Snapin with UT-A1 cRNA in Xenopus oocytes significantly increases urea influx; in the absence of Snapin, UT-A1 combined with t-SNARE components syntaxin-4 and SNAP-23 shows decreased urea influx. Yeast two-hybrid, GST pulldown, co-immunoprecipitation, Xenopus oocyte urea transport assay, confocal co-localization The Journal of biological chemistry Medium 17702749
2008 Loss of dysbindin in sandy (sdy) mice reduces steady-state Snapin protein levels; a 30-residue dysbindin peptide (residues 90–119) mediates interaction with Snapin, indicating dysbindin stabilises Snapin in vivo. Immunoblotting in sdy mice, peptide mapping of interaction domain Schizophrenia research Medium 18774265
2009 Snapin deficiency in cortical neurons results in EPSCs with multiple peaks and increased rise/decay times (desynchronized SV fusion), reduced mini-EPSC frequency, and smaller readily releasable pool. Transient Snapin expression rescues kinetics defects. A dimerization-defective Snapin-C66A mutant with impaired SNAP-25 and synaptotagmin interactions reduces RRP size but has less effect on synchrony, suggesting a dual role: Snapin dimerization fine-tunes synchronous fusion while monomer interactions regulate priming. Snapin-deficient mouse neurons, whole-cell patch-clamp, overexpression rescue, C66A dimerization mutant Neuron High 19217378
2009 Snapin associates with late endocytic compartments and interacts with late endosome-targeted SNARE complex components syntaxin 8 and Vti1b. Deleting snapin in mice leads to selective accumulation of LAMP-1, syntaxin 8, and Vti1b in late endocytic organelles, indicating Snapin regulates the late endocytic fusion machinery. Co-immunoprecipitation, subcellular fractionation, immunofluorescence, snapin KO mouse model, immunoblotting Bioscience reports Medium 19335339
2010 Snapin acts as a dynein motor adaptor that recruits dynein to late endosomes for retrograde transport; Snapin deficiency impairs late endosomal-lysosomal trafficking, leads to clustering of late endosomes in neuronal processes, and impairs autophagy-lysosomal function and autolysosome clearance, reducing neuron viability. Reintroducing the snapin transgene rescues these defects. Snapin KO mice, live imaging, co-immunoprecipitation (Snapin–dynein), retrograde transport assays, autolysosome accumulation assay, genetic rescue Neuron (referenced via PMID:20920785 review and PMID:21233602) High 20920785 21233602
2011 Snapin mediates GLP-1/incretin action on insulin secretion: PKA-dependent phosphorylation of Snapin increases interaction among insulin secretory vesicle-associated proteins, potentiating glucose-stimulated insulin secretion (GSIS). In diabetic islets with impaired GSIS, Snapin phosphorylation is reduced; expression of a phosphomimetic Snapin mutant restores GSIS. PKA phosphorylation assay, co-immunoprecipitation in islets, Snapin phosphomimetic expression in diabetic islets, insulin secretion assay Cell metabolism Medium 21356520
2011 AC6 forms a complex with Snapin and SNAP-25 in a phosphorylation-dependent manner at its N-terminus (AC6-N). This complex suppresses neurite outgrowth. Disruption by Snapin(Δ33–51) or Snapin(S50A) mutants (which cannot bind AC6 or SNAP-25 respectively) reverses the inhibitory effect of AC6 on neurite extension. Overexpression of SNAP-25 also reverses AC6 action, indicating SNAP-25 competes in the complex. Pull-down, co-immunoprecipitation, AC activity assay, neurite length quantification in hippocampal neurons and Neuro2A, AC6 KO neurons, Snapin knockdown Molecular and cellular biology Medium 21986494
2012 Snapin, as a dynein adaptor, mediates retrograde axonal transport of TrkB (BDNF) signaling endosomes. Deleting snapin or disrupting Snapin–dynein interaction abolishes TrkB retrograde transport, impairs BDNF-induced retrograde signaling from axonal terminals to the nucleus, and decreases dendritic growth of cortical neurons. Re-introducing the snapin gene rescues all defects. Snapin KO mice, compartmentalized microfluidic cultures of cortical neurons, live imaging of fluorescently tagged TrkB endosomes, Snapin–dynein interaction-disrupting mutants, nuclear signaling assay, dendritic morphometry, genetic rescue Cell reports High 22840395
2012 Atg14L directly binds Snapin and co-localizes with it. This interaction facilitates endosome maturation without affecting autophagic cargo degradation. Atg14L knockdown delays late-stage endocytic trafficking (retarded receptor degradation); this is rescued by wild-type Atg14L or a Beclin-1-binding mutant but not by a Snapin-binding mutant of Atg14L. Co-immunoprecipitation, co-localization, siRNA knockdown, receptor degradation kinetics assay, rescue with Atg14L point mutants Journal of cell science Medium 22797916
2012 Snapin is required for presynaptic homeostatic plasticity at the Drosophila NMJ. Loss of snapin blocks homeostatic modulation of presynaptic vesicle release following both pharmacological and genetic inhibition of postsynaptic glutamate receptors. Snapin does not alter baseline transmission, synapse morphology, or active zone number. Genetic evidence indicates snapin functions with dysbindin to modulate vesicle release, and interaction of Snapin with SNAP-25 is also required for synaptic homeostasis. Drosophila snapin loss-of-function, electrophysiology at NMJ, pharmacological GluR inhibition, double mutant (snapin;dysbindin) genetic epistasis The Journal of neuroscience High 22723711
2012 The phosphomimetic mutation S50D and the Cys-66 dimerization mutation alter Snapin protein structure and stability in vitro: S50D loses α-helical structure and thermal stability and disrupts tetrameric assemblies to favour dimers, while C66A abolishes subunit dimerization but not higher-order oligomers. S50D exhibits the strongest binding to the SNARE complex in vitro, consistent with enhanced cellular activity of PKA-phosphorylated Snapin. CD spectroscopy, fluorescence anisotropy, thermal stability assay, size-exclusion chromatography, in vitro SNARE pulldown with recombinant proteins Biochemistry Medium 22471585
2013 LRRK2 interacts with Snapin via its ROC and N-terminal domains and phosphorylates Snapin at threonine 117 in vitro. The phosphomimetic T117D mutant decreases Snapin–SNAP-25 interaction and, when added to rat brain lysate, reduces synaptotagmin association with the SNARE complex. LRRK2-dependent phosphorylation of Snapin in hippocampal neurons decreases the number of readily releasable vesicles and extent of exocytotic release. Yeast two-hybrid, GST pulldown, in vitro kinase assay, mutagenesis (T117D), co-immunoprecipitation, electrophysiology in hippocampal neurons Experimental & molecular medicine Medium 23949442
2013 Snapin, as a dynein adaptor for late endosomes, mediates BACE1 retrograde transport to lysosomes for degradation. In hAPP mutant neurons, reduced Snapin–dynein coupling leads to BACE1 accumulation in late endocytic organelles and impaired lysosomal targeting, enhancing APP processing. Overexpressing Snapin in hAPP neurons reduces β-site cleavage of APP by enhancing BACE1 turnover. Snapin KO mice, live axonal transport imaging, snapin–dynein interaction-disrupting mutants, BACE1 trafficking and degradation assays, APP processing/Aβ measurement, genetic rescue Cell reports High 24373968
2013 In C. elegans, loss of snpn-1 (Snapin) reduces the number of docked, fusion-competent synaptic vesicles but does not affect kinetics of transmission. Double mutant analysis of snt-1;snpn-1 indicates SNPN-1's role in vesicle docking/priming is independent of synaptotagmin, suggesting Snapin stabilises SNARE complex formation upstream of synaptotagmin's Ca2+-sensing function. C. elegans snpn-1 loss-of-function, electrophysiology at NMJ, electron microscopy (docked vesicle count), snt-1;snpn-1 double mutant epistasis PloS one Medium 23469084
2015 Snapin acts as a dynein adaptor for retrograde transport of late endosomes (LEs), and interacts with dysbindin (BLOC-1 subunit). Expressing dynein-binding-defective Snapin mutants induces SV accumulation at presynaptic terminals. Overexpressing Snapin reduces SV pool size by enhancing SV trafficking to the endolysosomal pathway. Snapin–dysbindin interaction regulates SV positional priming through BLOC-1/AP-3-dependent sorting; LE retrograde transport regulates SV pool size, while BLOC-1/AP-3 sorting fine-tunes Ca2+-sensitivity of SV release. Snapin KO neurons, dynein-binding mutants, SV-targeted Ca2+ sensor, overexpression, live imaging, electrophysiology The EMBO journal High 26108535
2016 SNAPIN is required for lysosomal acidification and autophagosome maturation in macrophages. Silencing SNAPIN impairs cathepsin D activation and lysosomal hydrolysis, and causes lysosomal proton leak (the primary mechanism) with a modest reduction in H+ pump activity, leading to incomplete lysosomal hydrolysis and impaired autophagy flux. siRNA knockdown in primary human macrophages, ratiometric fluorescence live-cell imaging of lysosomal pH, cathepsin D activity assay, lysosomal fusion assay, autophagy flux measurement Autophagy Medium 27929705
2016 Snapin directly interacts with Cav1.3 L-type Ca2+ channel and promotes ubiquitin-proteasomal degradation of Cav1.3, reducing total and membrane Cav1.3 expression and ICa-L density. SNAP-23 competitively reverses Snapin-induced Cav1.3 downregulation. Yeast two-hybrid, GST pulldown, co-immunoprecipitation in HEK cells and mouse atrial myocytes, overexpression, patch-clamp, ubiquitination assay, competition with SNAP-23 Cellular signalling Medium 27915047
2016 Snapin promotes HIV-1 trans-infection of CD4+ T cells by dampening TLR8 signaling in dendritic cells. Inhibition of Snapin enhances HIV-1 localisation with TLR8+ early endosomes, triggers pro-inflammatory response, and inhibits trans-infection. Snapin acts as a general regulator of endosomal maturation and inhibits TLR8 signaling independently of HIV-1. Phosphoproteomic screen, siRNA knockdown in DCs, co-localisation microscopy, TLR8 signaling assay, HIV-1 trans-infection assay The EMBO journal Medium 28923824
2017 Snapin directly binds the C-terminal domain of the dopamine transporter (DAT). Snapin co-localises with DAT in dopaminergic neurons in vivo and in vitro. Snapin co-expression produces a significant decrease in DAT uptake activity. Snapin downregulation in mice increases DAT levels and transport activity, thereby increasing DA concentration and locomotor response to amphetamine. Two-hybrid screening, co-immunoprecipitation, co-localisation, DAT uptake assay, Snapin KD in vivo (mice), locomotor assay, 3D interaction model Neuropsychopharmacology Medium 28905875
2021 p38α-MAPK directly phosphorylates Snapin (identified phosphorylation site: serine 112 by mass spectrometry and site-directed mutagenesis). Deletion of p38α-MAPK in neurons decreases Snapin serine phosphorylation, increases retrograde transport of BACE1 in axons, and reduces BACE1 at synaptic terminals. S112A substitution abolishes the p38α-KD-induced reduction in BACE1 activity, protein level, and lysosomal targeting, confirming S112 as the functional phosphorylation site. APP-transgenic mice, p38α neuron-specific KO, in vitro kinase assay, mass spectrometry, site-directed mutagenesis (S112A), BACE1 retrograde transport imaging, BACE1 activity assay in SH-SY5Y cells FASEB journal Medium 34118085
2022 DYRK3 directly phosphorylates Snapin at threonine 14. Phosphorylation at T14 increases Snapin interactions with dynein and synaptotagmin-1. Phospho-T14 Snapin positively modulates mitochondrial retrograde transport in cortical neurons and increases the recycling pool size of synaptic vesicles, contributing to neuronal viability. Yeast two-hybrid, in vitro kinase assay, phosphosite mutagenesis (T14), co-immunoprecipitation, live mitochondrial transport imaging in cortical neurons, electrophysiology (recycling pool size) Cell death discovery Medium 36585413
2025 CK1δ-mediated hyperphosphorylation of Snapin (induced by HIV-1 Vpr) disrupts lysosomal positioning and motility in neurons. Selective CK1δ inhibition restores lysosomal acidification, positioning, and mitophagy. This defines a Vpr–CK1δ–Snapin axis driving lysosomal dysfunction in neurons. Vpr treatment of neurons, CK1δ inhibitor, lysosomal positioning/motility assay, lysosomal acidification assay, mitophagy assay; co-IP confirmation of CK1δ–Snapin interaction iScience Medium 41567242
2025 Snapin binds CBS (cystathionine β-synthase; confirmed by molecular docking and co-immunoprecipitation), disrupting H2S metabolic homeostasis and reducing endogenous H2S levels after mTBI. Reduced H2S limits S-sulfhydration of pro-CTSD, promoting its maturation into active CTSD and inducing PANoptosis. Conditional neuronal knockdown of Snapin attenuates neurodegeneration and improves functional recovery in mice. CCI mTBI mouse model, AAV-shSnapin conditional KD, co-immunoprecipitation (Snapin–CBS), molecular docking, modified biotin switch assay (CTSD S-sulfhydration), sulfide electrode H2S measurement, PANoptosis protein analysis, behavioral testing Journal of advanced research Medium 41558604
2025 SNAPIN facilitates degradation of KEAP1 via the autophagolysosomal pathway; SNAPIN directly binds KEAP1, promoting its lysosomal turnover, which stabilises NRF2 and upregulates GPX4, thereby reducing lipid peroxidation and inhibiting ferroptosis in hepatocellular carcinoma cells. SNAPIN overexpression/knockdown in HCC cells, co-immunoprecipitation (SNAPIN–KEAP1), lysosomal degradation inhibition assay, NRF2/GPX4 immunoblotting, ferroptosis induction assay Cancer science Low 41190709

Source papers

Stage 0 corpus · 68 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2004 Identification of snapin and three novel proteins (BLOS1, BLOS2, and BLOS3/reduced pigmentation) as subunits of biogenesis of lysosome-related organelles complex-1 (BLOC-1). The Journal of biological chemistry 221 15102850
1999 Snapin: a SNARE-associated protein implicated in synaptic transmission. Nature neuroscience 207 10195194
2001 Phosphorylation of Snapin by PKA modulates its interaction with the SNARE complex. Nature cell biology 142 11283605
2006 Dysbindin-1 is a synaptic and microtubular protein that binds brain snapin. Human molecular genetics 128 16980328
2012 Snapin recruits dynein to BDNF-TrkB signaling endosomes for retrograde axonal transport and is essential for dendrite growth of cortical neurons. Cell reports 117 22840395
2008 Dysbindin deficiency in sandy mice causes reduction of snapin and displays behaviors related to schizophrenia. Schizophrenia research 105 18774265
2011 Snapin mediates incretin action and augments glucose-dependent insulin secretion. Cell metabolism 97 21356520
2005 The role of Snapin in neurosecretion: snapin knock-out mice exhibit impaired calcium-dependent exocytosis of large dense-core vesicles in chromaffin cells. The Journal of neuroscience : the official journal of the Society for Neuroscience 92 16280592
2009 Snapin facilitates the synchronization of synaptic vesicle fusion. Neuron 72 19217378
2003 Identification and characterization of Snapin as a ubiquitously expressed SNARE-binding protein that interacts with SNAP23 in non-neuronal cells. The Biochemical journal 71 12877659
2004 Effects of PKA-mediated phosphorylation of Snapin on synaptic transmission in cultured hippocampal neurons. The Journal of neuroscience : the official journal of the Society for Neuroscience 55 15269257
2013 Snapin-mediated BACE1 retrograde transport is essential for its degradation in lysosomes and regulation of APP processing in neurons. Cell reports 52 24373968
2012 Snapin is critical for presynaptic homeostatic plasticity. The Journal of neuroscience : the official journal of the Society for Neuroscience 51 22723711
2013 LRRK2 phosphorylates Snapin and inhibits interaction of Snapin with SNAP-25. Experimental & molecular medicine 50 23949442
2012 Beclin-1-interacting autophagy protein Atg14L targets the SNARE-associated protein Snapin to coordinate endocytic trafficking. Journal of cell science 46 22797916
2008 CREB3L4, INTS3, and SNAPAP are targets for the 1q21 amplicon frequently detected in hepatocellular carcinoma. Cancer genetics and cytogenetics 44 18068530
2005 A novel role for snapin in dendrite patterning: interaction with cypin. Molecular biology of the cell 43 16120643
2015 Regulation of synaptic activity by snapin-mediated endolysosomal transport and sorting. The EMBO journal 42 26108535
2004 Reinvestigation of the role of snapin in neurotransmitter release. The Journal of biological chemistry 42 15084593
2016 SNAPIN is critical for lysosomal acidification and autophagosome maturation in macrophages. Autophagy 41 27929705
2007 Snapin interacts with the Exo70 subunit of the exocyst and modulates GLUT4 trafficking. The Journal of biological chemistry 40 17947242
2005 EBAG9 adds a new layer of control on large dense-core vesicle exocytosis via interaction with Snapin. Molecular biology of the cell 39 15635093
2004 Regulation of type VI adenylyl cyclase by Snapin, a SNAP25-binding protein. The Journal of biological chemistry 38 15319443
2007 Snapin, a new regulator of receptor signaling, augments alpha1A-adrenoceptor-operated calcium influx through TRPC6. The Journal of biological chemistry 36 17684020
2012 SNAPIN: an endogenous Toll-like receptor ligand in rheumatoid arthritis. Annals of the rheumatic diseases 32 22523426
2013 Transmembrane prostatic acid phosphatase (TMPAP) interacts with snapin and deficient mice develop prostate adenocarcinoma. PloS one 31 24039861
2003 Snapin interacts with the N-terminus of regulator of G protein signaling 7. Biochemical and biophysical research communications 31 12659861
2006 Casein kinase 1 delta (CK1delta) interacts with the SNARE associated protein snapin. FEBS letters 27 17101137
2011 Uncovering the role of Snapin in regulating autophagy-lysosomal function. Autophagy 24 21233602
2007 The UT-A1 urea transporter interacts with snapin, a SNARE-associated protein. The Journal of biological chemistry 23 17702749
2006 Ryanodine receptor interaction with the SNARE-associated protein snapin. Journal of cell science 23 16723744
2011 Human cytomegalovirus primase UL70 specifically interacts with cellular factor Snapin. Journal of virology 22 21917956
2009 Novel regulation of adenylyl cyclases by direct protein-protein interactions: insights from snapin and ric8a. Neuro-Signals 22 19202347
2013 Differential roles for snapin and synaptotagmin in the synaptic vesicle cycle. PloS one 21 23469084
2009 Snapin associates with late endocytic compartments and interacts with late endosomal SNAREs. Bioscience reports 21 19335339
2014 Chlamydia psittaci inclusion membrane protein IncB associates with host protein Snapin. International journal of medical microbiology : IJMM 20 24751478
2011 Type VI adenylyl cyclase regulates neurite extension by binding to Snapin and Snap25. Molecular and cellular biology 20 21986494
2017 Snapin promotes HIV-1 transmission from dendritic cells by dampening TLR8 signaling. The EMBO journal 15 28923824
2010 EHD1 is a synaptic protein that modulates exocytosis through binding to snapin. Molecular and cellular neurosciences 15 20696250
2022 DYRK3 phosphorylates SNAPIN to regulate axonal retrograde transport and neurotransmitter release. Cell death discovery 13 36585413
2013 Modulation of the cellular distribution of human cytomegalovirus helicase by cellular factor Snapin. Journal of virology 13 23885069
2011 Snapin deficiency is associated with developmental defects of the central nervous system. Bioscience reports 13 20946101
2016 Physical and functional interaction of Snapin with Cav1.3 calcium channel impacts channel protein trafficking in atrial myocytes. Cellular signalling 12 27915047
2021 P38α-MAPK phosphorylates Snapin and reduces Snapin-mediated BACE1 transportation in APP-transgenic mice. FASEB journal : official publication of the Federation of American Societies for Experimental Biology 11 34118085
2018 Interaction of porcine reproductive and respiratory syndrome virus major envelope proteins GP5 and M with the cellular protein Snapin. Virus research 11 29577951
2010 Snapin snaps into the dynein complex for late endosome-lysosome trafficking and autophagy. Neuron 11 20920785
2016 Snapin mediates insulin secretory granule docking, but not trans-SNARE complex formation. Biochemical and biophysical research communications 9 26946359
2016 Host protein Snapin interacts with human cytomegalovirus pUL130 and affects viral DNA replication. Journal of biosciences 9 27240978
2009 The SNARE-associated component SNAPIN binds PUMILIO2 and NANOS1 proteins in human male germ cells. Molecular human reproduction 9 19168546
2017 Structural and Functional Characterization of the Interaction of Snapin with the Dopamine Transporter: Differential Modulation of Psychostimulant Actions. Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology 8 28905875
2015 Snapin interacts with G-protein coupled receptor PKR2. Biochemical and biophysical research communications 7 26687946
2014 Interaction between the human cytomegalovirus‑encoded UL142 and cellular Snapin proteins. Molecular medicine reports 7 25369979
2012 Mutation of Ser-50 and Cys-66 in Snapin modulates protein structure and stability. Biochemistry 7 22471585
2010 Functional characterization of the central hydrophilic linker region of the urea transporter UT-A1: cAMP activation and snapin binding. American journal of physiology. Cell physiology 7 20457831
2021 SNAPIN Regulates Cell Cycle Progression to Promote Pancreatic β Cell Growth. Frontiers in endocrinology 6 34194388
2006 Interaction between Snapin and G-CSF receptor. Cytokine 6 16595180
2023 The role of snapin in regulation of brain homeostasis. Neural regeneration research 5 38103234
2013 Snapin, positive regulator of stimulation- induced Ca²⁺ release through RyR, is necessary for HIV-1 replication in T cells. PloS one 5 24130701
2006 Modeling of the potential coiled-coil structure of snapin protein and its interaction with SNARE complex. Bioinformation 4 17597906
2025 Autism-Associated PTCHD1 Missense Variants Bind to the SNARE-Associated Protein SNAPIN but Exhibit Impaired Subcellular Trafficking. Biological psychiatry global open science 2 40475291
2021 Snapin Specifically Up-Regulates Cav1.3 Ca2+ Channel Variant with a Long Carboxyl Terminus. International journal of molecular sciences 2 34681928
2023 Interaction between the VP2 protein of deformed wing virus and host snapin protein and its effect on viral replication. Frontiers in microbiology 1 36846748
2026 Snapin mediates neuronal PANoptosis after mild traumatic brain injury via H2S-dependent S-sulfhydration of CTSD. Journal of advanced research 0 41558604
2025 CK1δ-Dependent SNAPIN Dysregulation Drives Lysosomal Failure in HIV-1 Vpr-Exposed Neurons: A Targetable Mechanism in HAND. bioRxiv : the preprint server for biology 0 40791547
2025 Bi-allelic deleterious variants in SNAPIN, which encodes a retrograde dynein adaptor, cause a prenatal-onset neurodevelopmental disorder. American journal of human genetics 0 40930097
2025 SNAPIN Facilitates Progression of Hepatocellular Carcinoma by Hindering Ferroptosis Through KEAP1 Degradation Promotion. Cancer science 0 41190709
2025 Targeted NanoBiT Screening Identifies a Novel Interaction Between SNAPIN and Influenza A Virus M1 Protein. Biology 0 41463543
2025 CK1δ-dependent SNAPIN dysregulation drives lysosomal failure in HIV-1 Vpr-exposed neurons: A targetable mechanism in HAND. iScience 0 41567242

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