Affinage

BET1L

BET1-like protein · UniProt Q9NYM9

Length
111 aa
Mass
12.4 kDa
Annotated
2026-06-09
20 papers in source corpus 7 papers cited in narrative 8 extracted findings
Cross-family judge vs UniProt: Affinage preferred faithfulness: 7/7 claims corpus-supported (100%)

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

BET1L (GS15) is a Golgi-resident v-SNARE that mediates membrane fusion in intra-Golgi and endosome-to-Golgi transport (PMID:9242691, PMID:15215310). It is a 15 kDa integral membrane protein enriched in medial-Golgi cisternae and behaves biochemically as a SNARE (PMID:9242691, PMID:12388752). BET1L assembles into a defined SNARE complex with syntaxin 5, GS28, and Ykt6, and its loss disrupts Golgi architecture, redistributing Golgi markers into dispersed puncta (PMID:12388752). This same complex drives transport from the early/recycling endosome to the trans-Golgi network, where antibody inhibition or knockdown of BET1L blocks Shiga toxin B-subunit delivery, and BET1L cycles between endosomes and the Golgi (PMID:15215310). Its function is integrated with vesicle tethering machinery: BET1L physically contacts the COG lobe B sub-complex on vesicle-like structures (PMID:27385402) and is destabilized upon acute GARP disruption. In skeletal muscle, BET1L localizes to the neuromuscular junction basal lamina, and its knockdown causes NMJ denervation, motor neuron loss, and motor impairment (PMID:39896335). BET1L expression is post-transcriptionally controlled through miR-140-3p binding and m6A modification at its 3'UTR, with a regulatory SNP linked to colorectal cancer cell growth (PMID:37115853).

Mechanistic history

Synthesis pass · year-by-year structured walk · 8 steps
  1. 1997 Medium

    Established that the mammalian Bet1p homolog GS15/BET1L is a Golgi-enriched integral membrane protein with SNARE biochemical behavior, defining it as a vesicular transport SNARE.

    Evidence Affinity-purified antibodies, immunofluorescence, and biochemical fractionation of a 15 kDa Golgi protein

    PMID:9242691

    Open questions at the time
    • No SNARE partners identified
    • Specific transport step not defined
    • No loss-of-function phenotype
  2. 2002 High

    Resolved BET1L's molecular partners and cellular requirement, showing it forms a distinct medial-Golgi SNARE complex with syntaxin 5/GS28/Ykt6 and is essential for Golgi structural integrity.

    Evidence Immuno-EM, reciprocal co-IP, siRNA knockdown with Golgi-fragmentation phenotype, and dominant-negative overexpression

    PMID:12388752

    Open questions at the time
    • Directionality of transport not fully separated from structural maintenance
    • COPI co-IP relationship mechanistically unresolved
  3. 2004 High

    Defined a specific transport step for the BET1L SNARE complex — endosome-to-TGN retrograde transport — distinguishing it from ER-to-Golgi function.

    Evidence In vitro Shiga toxin B-subunit transport assay, antibody inhibition, siRNA knockdown, and SNX3-induced redistribution imaging in HeLa cells

    PMID:15215310

    Open questions at the time
    • Mechanism of endosome-Golgi cycling not detailed
    • Regulation of complex assembly between compartments unknown
  4. 2016 Medium

    Connected BET1L to vesicle tethering machinery by showing the COG lobe B sub-complex contacts the v-SNARE on vesicle-like structures, spatially separate from Golgi-stack-bound lobe A.

    Evidence Super-resolution microscopy, physical interaction assays, and dominant-negative COG constructs

    PMID:27385402

    Open questions at the time
    • Direct vs. indirect COG-BET1L contact not distinguished
    • Functional consequence of the interaction for fusion not measured
  5. 2021 Low

    Extended BET1L localization beyond the Golgi to the NMJ basal lamina and linked declining expression to ALS disease progression.

    Evidence Immunohistochemistry of rat NMJ and RNA-seq of iPSC-myocytes and SOD1G93A ALS rat muscle

    PMID:34310943

    Open questions at the time
    • Localization without established functional consequence
    • Causal vs. correlative link to ALS unresolved
    • No mechanistic follow-up of NMJ role
  6. 2023 Medium

    Revealed post-transcriptional control of BET1L through a 3'UTR SNP altering miR-140-3p binding and m6A modification, with consequences for colorectal cancer cell growth.

    Evidence Luciferase reporter, m6A assays, RNA-seq pathway analysis, in vitro/in vivo growth assays, and miR-140-3p rescue

    PMID:37115853

    Open questions at the time
    • Link between SNARE/Golgi function and proliferation not established
    • Mechanism connecting BET1L to steroid biosynthesis genes unresolved
  7. 2024 Low

    Placed BET1L downstream of GARP-dependent tethering, showing acute GARP loss leads to its mislocalization and degradation.

    Evidence mAID degron-mediated VPS54 depletion with immunofluorescence and western blot (preprint)

    Open questions at the time
    • Preprint, not peer-reviewed
    • BET1L is one of many affected proteins
    • No BET1L-specific mechanistic follow-up
  8. 2025 Medium

    Established a functional in vivo requirement for BET1L in NMJ maintenance, with muscle-specific knockdown causing denervation, motor neuron loss, and motor deficits.

    Evidence In vivo siRNA knockdown in rat hindlimb muscle with NMJ immunohistochemistry, motor neuron morphometry, and behavioral testing

    PMID:39896335

    Open questions at the time
    • Mechanism linking SNARE/trafficking function to NMJ maintenance unknown
    • Cell-autonomous vs. non-autonomous contribution unresolved

Open questions

Synthesis pass · forward-looking unresolved questions
  • How BET1L's core Golgi/endosomal SNARE trafficking function mechanistically connects to its NMJ-maintenance role and to its tumor-promoting activity remains unresolved.
  • No mechanistic link between vesicle fusion and motor neuron/NMJ phenotype
  • No structural model of the SNARE complex
  • Tissue-specific regulation of BET1L function unknown

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0005198 structural molecule activity 2
Localization
GO:0005794 Golgi apparatus 3 GO:0005768 endosome 1
Pathway
R-HSA-5653656 Vesicle-mediated transport 2 R-HSA-9609507 Protein localization 1
Partners
COG5GOSR1STX5YKT6
Complex memberships
syntaxin 5/GS28/Ykt6/GS15 SNARE complex

Evidence

Reading pass · 8 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
1997 GS15 (BET1L) is a 15 kDa integral membrane protein highly enriched in Golgi membranes that behaves biochemically as a SNARE protein, identified as a mammalian homolog of yeast Bet1p involved in vesicular transport. Affinity-purified polyclonal antibodies, indirect immunofluorescence microscopy, biochemical fractionation/characterization The Journal of biological chemistry Medium 9242691
2002 GS15 (BET1L) localizes to medial-cisternae of the Golgi apparatus (not the IC/ER exit sites), exists in a distinct SNARE complex with syntaxin 5, GS28, and Ykt6 (but not with ER-to-Golgi-exclusive SNAREs), co-immunoprecipitates with COPI coat components from Golgi extracts, and is essential for normal Golgi structure — its knockdown redistributes Golgi markers into small dotty/diffuse patterns. Immuno-electron microscopy, co-immunoprecipitation, siRNA knockdown, overexpression of dominant-negative mutants, indirect immunofluorescence Molecular biology of the cell High 12388752
2004 GS15 (BET1L) functions as part of the syntaxin 5/Ykt6/GS28/GS15 SNARE complex specifically in transport from the early/recycling endosome (EE/RE) to the trans-Golgi network (TGN); antibody inhibition of GS15 blocks STxB transport, and siRNA knockdown of GS15 blocks recombinant STxB transport in HeLa cells. GS15 and Ykt6 redistribute from Golgi to endosomes when the recycling endosome is perturbed by SNX3-overexpression, suggesting cycling between endosomes and Golgi. In vitro transport assay with Shiga toxin B subunit, antibody inhibition, siRNA knockdown, immunofluorescence with SNX3 overexpression Molecular biology of the cell High 15215310
2016 COG lobe B sub-complex (COG5-8) physically interacts with v-SNARE GS15 (BET1L) on vesicle-like structures at the Golgi, as demonstrated by super-resolution microscopy showing spatial separation of COG lobe A (on Golgi stacks) and lobe B (on vesicle-like structures where it contacts GS15). Super-resolution microscopy, co-immunoprecipitation/interaction assays, dominant-negative COG constructs Scientific reports Medium 27385402
2021 Bet1L (BET1L) protein is localized to the basal lamina of the neuromuscular junction (NMJ) in rat skeletal muscle, and its expression decreases over time in the SOD1G93A ALS rat model, beginning early in disease progression. Immunofluorescence/immunohistochemistry of rat NMJ tissue, RNA sequencing of iPSC-derived myocytes and ALS rat hindlimb muscle Experimental neurology Low 34310943
2024 GS15 (BET1L) undergoes partial mislocalization and degradation upon acute GARP complex disruption (rapid VPS54 depletion via mAID degron), placing GS15 downstream of GARP-dependent vesicle tethering at the TGN. mAID degron-mediated acute protein degradation, immunofluorescence, western blot bioRxivpreprint Low
2025 Muscle-specific Bet1L (BET1L) knockdown via siRNA injection into hindlimb muscle of ALS (SOD1G93A) and wild-type rats caused increased denervated NMJs, decreased motor neuron size in lumbar spinal cord, and impaired hindlimb motor function; effects were more severe in ALS rats, establishing a functional role for Bet1L in NMJ maintenance. In vivo siRNA knockdown in rat hindlimb muscle, NMJ immunohistochemistry, motor neuron morphometry, behavioral motor function tests Frontiers in neuroscience Medium 39896335
2023 A SNP (rs11245997) in the BET1L 3'UTR disrupts miR-140-3p binding and reduces m6A modification (mediated by METTL14/WTAP/ALKBH5), leading to upregulated BET1L expression that promotes colorectal cancer cell growth in vitro and in vivo; BET1L expression was associated with regulation of HSD17B7, CYP27B1, and COMT in the steroid biosynthesis pathway. Luciferase reporter assays for miRNA binding, m6A methylation assays, RNA-seq pathway analysis, in vitro proliferation assays, in vivo xenograft models, miR-140-3p overexpression rescue Cancer research Medium 37115853

Source papers

Stage 0 corpus · 20 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2004 Participation of the syntaxin 5/Ykt6/GS28/GS15 SNARE complex in transport from the early/recycling endosome to the trans-Golgi network. Molecular biology of the cell 135 15215310
2002 GS15 forms a SNARE complex with syntaxin 5, GS28, and Ykt6 and is implicated in traffic in the early cisternae of the Golgi apparatus. Molecular biology of the cell 104 12388752
1997 GS15, a 15-kilodalton Golgi soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) homologous to rbet1. The Journal of biological chemistry 47 9242691
2009 Phenol degradation in the strictly anaerobic iron-reducing bacterium Geobacter metallireducens GS-15. Applied and environmental microbiology 44 19376902
2007 Plutonium(IV) reduction by the metal-reducing bacteria Geobacter metallireducens GS15 and Shewanella oneidensis MR1. Applied and environmental microbiology 34 17644643
2013 BET1L and TNRC6B associate with uterine fibroid risk among European Americans. Human genetics 32 23604678
2016 COG lobe B sub-complex engages v-SNARE GS15 and functions via regulated interaction with lobe A sub-complex. Scientific reports 27 27385402
2013 Variants in BET1L and TNRC6B associate with increasing fibroid volume and fibroid type among European Americans. Human genetics 25 23892540
2009 Plutonium(V/VI) Reduction by the Metal-Reducing Bacteria Geobacter metallireducens GS-15 and Shewanella oneidensis MR-1. Applied and environmental microbiology 24 19363069
1991 Acetate catabolism in the dissimilatory iron-reducing isolate GS-15. Journal of bacteriology 22 1901574
2006 Effects of the overexpression of a soybean cytosolic glutamine synthetase gene (GS15) linked to organ-specific promoters on growth and nitrogen accumulation of pea plants supplied with ammonium. Plant physiology and biochemistry : PPB 16 17067806
2013 Structure determination and biochemical characterization of a putative HNH endonuclease from Geobacter metallireducens GS-15. PloS one 15 24039739
2023 Genetic Modulation of BET1L Confers Colorectal Cancer Susceptibility by Reducing miRNA Binding and m6A Modification. Cancer research 14 37115853
2002 A novel HMG A-like protein binds differentially to the AT-rich regions located in the far distal and proximal parts of a soybean glutamine synthetase gene (GS15) promoter. Plant & cell physiology 10 12354918
2021 Transcriptome analysis using patient iPSC-derived skeletal myocytes: Bet1L as a new molecule possibly linked to neuromuscular junction degeneration in ALS. Experimental neurology 9 34310943
2019 Replication of GWAS Loci Revealed an Increased Risk of BET1L and H19 Polymorphisms with Intracranial Aneurysm. Disease markers 6 31275455
2023 Genome-wide association study reveals BET1L associated with survival time in the 137,693 Japanese individuals. Communications biology 5 36737517
2022 Risk of uterine leiomyoma based on BET1L rs2280543 single nucleotide polymorphism and vegetarian diet. BMC women's health 5 35477381
2024 Quinolone antibiotics stimulate bacterial mercury methylation by Geobacter metallireducens GS-15. Bioresource technology 4 39260732
2025 Muscle-specific Bet1L knockdown induces neuromuscular denervation, motor neuron degeneration, and motor dysfunction in a rat model of familial ALS. Frontiers in neuroscience 3 39896335

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