| 2012 |
Fis1 acts as a mitochondrial receptor that directly recruits TBC1D15 to the mitochondrial outer membrane; bacterially expressed Fis1 and TBC1D15 form a direct and stable complex, and TBC1D15 (normally cytoplasmic) relocalizes to mitochondria when co-expressed with Fis1. Knockdown of TBC1D15 induces highly developed mitochondrial network structures, placing TBC1D15 in regulation of mitochondrial morphology independently of Drp1. |
Co-immunoprecipitation from HeLa cell extracts, bacterial reconstitution of direct complex, fluorescence microscopy of co-expressed proteins, siRNA knockdown with morphological readout |
Journal of cell science |
High |
23077178
|
| 2010 |
TBC1D15 functions as a Rab7 GTPase-activating protein (GAP) in cells, reducing Rab7 binding to its effector RILP (measured by effector pull-down assay), fragmenting lysosomes, and conferring resistance to growth factor withdrawal-induced cell death. TBC1D15 GAP activity is selective for Rab7 and does not affect Rab4-, Rab5-, or Rab11-dependent processes. |
Effector pull-down assay (RILP-Rab7-GTP binding), lysosomal morphology imaging, cell death assays, transferrin recycling assay as selectivity control |
The Journal of biological chemistry |
High |
20363736
|
| 2017 |
Crystal structures of the TBC1D15 GAP domain (shark and pig orthologs) were solved to 2.8 Å and 2.5 Å resolution, revealing conservation with but distinct variations from yeast Gyp1p and TBC1D1. Active-site mutagenesis (Arg→Ala or Lys) of the catalytic arginine and glutamine residues abolishes GAP activity, confirming the dual-finger catalytic mechanism. |
X-ray crystallography, in vitro GAP activity assay, active-site mutagenesis |
Protein science |
High |
28168758
|
| 2013 |
TBC1D15 is identified as a Numb-associated protein by large-scale affinity purification/mass spectrometry; its amino-terminal domain disengages p53 from the Numb–p53 complex, triggering p53 proteolysis and promoting stem cell self-renewal. TBC1D15 protein levels are reduced by autophagy-mediated degradation upon nutrient deprivation. |
Affinity purification and tandem mass spectrometry, co-immunoprecipitation, domain-mapping with deletion constructs, p53 stability assays, autophagy inhibitor experiments |
PloS one |
Medium |
23468968
|
| 2013 |
Depletion of TBC1D15 in HeLa cells induces RhoA activation and membrane blebbing, which is abolished by RhoA signaling inhibitors. TBC1D15 is also required for proper accumulation of RhoA at the equatorial cortex during cytokinesis, establishing a role for TBC1D15 in RhoA-mediated cortical dynamics. |
siRNA knockdown, RhoA activity assay (pull-down), pharmacological inhibition of RhoA, fluorescence microscopy of cytokinesis |
Molecular and cellular biochemistry |
Medium |
24337944
|
| 2019 |
Annexin A6 promotes Rab7 inactivation by stimulating TBC1D15 (Rab7-GAP) activity; AnxA6 depletion in NPC1 mutant cells leads to Rab7 activation, peripheral redistribution of late endosomes, and enhanced cholesterol export to lipid droplets via StARD3-dependent membrane contact sites between late endosomes and ER. |
Co-immunoprecipitation, effector pull-down (Rab7-GTP), fluorescence live-cell imaging, electron microscopy of membrane contact sites, ACAT inhibitor assays |
Cellular and molecular life sciences |
Medium |
31664461
|
| 2020 |
TBC1D15 regulates mitochondria-lysosome contacts through both its Fis1-binding domain and its Rab7 GAP domain; overexpression loosens abnormal mitochondria-lysosome contacts, restores lysosomal size and function, and rescues mitophagy flux after myocardial infarction. Interference with either domain individually abrogates the beneficial effects. |
Transmission electron microscopy, live-cell time-lapse imaging, adenoviral overexpression, domain-mutation rescue experiments, mitophagy flux assays (fluorescence and western blotting), cardiac functional assessment |
Theranostics |
High |
33042281
|
| 2020 |
IFNB/interferon-β induces expression of miR-1, which reduces TBC1D15 levels, thereby decreasing Rab7 activity and stimulating autophagy; this MIR1-TBC1D15-RAB7 pathway is conserved from humans to C. elegans and its disruption leads to late-stage autophagic flux block and α-synuclein accumulation. |
MicroRNA expression manipulation, TBC1D15 knockdown/overexpression, autophagy flux assays, cross-species genetic conservation analysis |
Autophagy |
Medium |
31958036
|
| 2022 |
TBC1D15 directly interacts with Drp1 through its C-terminal 574–624 domain and recruits Drp1 to mitochondria-lysosome contact sites to drive asymmetrical mitochondrial fission. Deletion of this domain (Δ574-624) or interference with TBC1D15–Drp1 interaction abrogates asymmetrical fission and mitochondrial function. TBC1D15 also operates via a Fis1/RAB7 cascade to regulate contact untethering. |
Cardiac-specific knockin/knockout mouse models, time-lapse confocal microscopy, domain-deletion and point-mutant rescue experiments (R400K, Δ231-240, Δ574-624), co-immunoprecipitation |
Metabolism: clinical and experimental |
High |
35680100
|
| 2023 |
Following lysosomal membrane damage, LIMP2 acts as a lysophagy receptor binding ATG8, which in turn recruits TBC1D15 to damaged lysosomes. TBC1D15 then interacts with ATG8 proteins and acts as a scaffold to assemble the autophagic lysosomal reformation (ALR) machinery (dynamin-2, kinesin-5B, clathrin), promoting lysosomal tubule formation and dynamin-2-dependent scission for membrane regeneration. |
Proximity-labeling proteomics, co-immunoprecipitation, high-resolution fluorescence microscopy, siRNA knockdown with lysosomal morphology and function readouts |
Nature cell biology |
High |
37024685
|
| 2023 |
TBC1D15 interacts with DNA-PKcs at the segment 594–624 of TBC1D15 (identified by LC-MS/MS and co-IP) and promotes cytosolic accumulation of DNA-PKcs; deletion of this segment (Δ594-624) abolishes the ability of TBC1D15 to foster DNA-PKcs cytosolic retention and doxorubicin-induced DNA damage. |
LC-tandem mass spectrometry, co-immunoprecipitation, domain-deletion mutagenesis, cardiac-specific knockout/knockin mouse models, DNA damage assays |
Acta pharmaceutica Sinica. B |
Medium |
38045047
|
| 2013 |
Drosophila Tbc1d15-17 (ortholog of mammalian TBC1D15/Rab7-GAP) is required for normal synaptic bouton number and NMJ length; loss-of-function or presynaptic knockdown causes synaptic overgrowth. Postsynaptic knockdown disrupts Dlg scaffold distribution and GluRIIA levels. Presynaptic overexpression of constitutively active Rab7 phenocopies Tbc1d15-17 loss, while dominant-negative Rab7 has the opposite effect, placing Tbc1d15-17 upstream of Rab7 in synaptic growth control. |
Drosophila loss-of-function genetics, tissue-specific RNAi knockdown, constitutively active/dominant-negative Rab7 epistasis, immunofluorescence microscopy at NMJ |
Molecules and cells |
Medium |
23812537
|
| 2017 |
TBC1D15 knockdown rescues nigericin-induced mitochondrial fission and restores STING pathway activation, whereas Drp1 knockdown rescues fission but does not restore STING activity. This places TBC1D15—but not Drp1—as the specific mediator through which inflammasome-activating signals curtail STING pathway activity. |
siRNA knockdown of TBC1D15 or Drp1, mitochondrial morphology imaging, STING pathway reporter assays (IFN-β, ISG56, TBK1, IRF3 activation) |
FASEB journal |
Medium |
28729291
|
| 2018 |
TBC1D15 regulates GLUT4 translocation and glucose uptake; CRISPR/Cas9 knockout of TBC1D15 reduces 2-NBDG uptake, decreases total GLUT4 protein, and causes GLUT4 to accumulate in Rab7-positive late endosomes/lysosomes, consistent with TBC1D15's Rab7 GAP activity controlling late endosomal GLUT4 trafficking. |
CRISPR/Cas9 knockout, fluorescent glucose analog uptake assay (2-NBDG), immunofluorescence co-localization of GLUT4 and Rab7/LAMP1 |
Gene |
Medium |
30316925
|
| 2024 |
TBC1D15 functions as a GAP for Arl4D (a Ras-family GTPase) in addition to Rab7; it interacts with Arl4D through the TBC domain and promotes GTP hydrolysis of Arl4D. Knockdown of TBC1D15 increases Arl4D-GTP levels and decreases Arl4D mitochondrial translocation under serum starvation, placing TBC1D15 as an upstream regulator of Arl4D mitochondrial targeting. |
Co-immunoprecipitation, in vitro GAP activity assay, TBC domain interaction mapping, TBC1D15 knockdown with Arl4D-GTP effector pull-down and mitochondrial localization readout |
Journal of cell science |
Medium |
41709823
|
| 2024 |
TBC1D15 stabilizes NOTCH1 by blocking CDK8/CDK19-mediated phosphorylation of the NOTCH1 PEST phosphodegron, thereby preventing FBW7-mediated ubiquitin-dependent degradation. The TBC1D15-FIS1 interaction recruits NOTCH1 to the mitochondrial outer membrane in the perinuclear region. TBC1D15 also binds NUMB isoform 5 (lacking Ser phosphorylation sites) and relocalizes NUMB5 to mitochondria. |
Co-immunoprecipitation, ChIP-seq, domain-interaction mapping, CDK8 kinase assays, in vivo triple-knockout mouse model (hepatocyte-specific Tbc1d15/Notch1/Notch2), PDX tumor models |
Experimental & molecular medicine |
Medium |
38409448
|
| 2023 |
FIS1 contains a conserved noncanonical 'SKY insert' (S45-K46-Y47) in its first TPR repeat that governs TBC1D15 and DRP1 recruitment to mitochondria. Deletion of the SKY insert (ΔSKY) reduces mitochondrial TBC1D15 and DRP1 recruitment despite DRP1 still co-immunoprecipitating with ΔSKY FIS1, demonstrating that the insert is required for productive mitochondrial fission complex assembly. |
Structure-based sequence alignment, FIS1 variant expression in HCT116 cells, co-immunoprecipitation, fluorescence microscopy of YFP-TBC1D15 recruitment, mitochondrial morphology analysis |
The Journal of biological chemistry |
Medium |
37777154
|
| 2025 |
TBC1D15 is translocated to the mitochondrial membrane in hepatocytes upon ethanol exposure, where it recruits PLIN5 through its 10–180 aa domain, promoting mitochondria-lipid droplet contacts. This interaction facilitates PKA-induced nuclear translocation of PLIN5 and upregulates PPARα/PGC1α/CPT1α, enhancing mitochondrial fatty acid β-oxidation; PKA inhibition nullifies these effects. |
Hepatocyte-specific TBC1D15 overexpression mouse model, co-immunoprecipitation, domain-mapping (10–180 aa), immunofluorescence microscopy, PKA inhibitor experiments, transmission electron microscopy |
Metabolism: clinical and experimental |
Medium |
40334909
|
| 2024 |
Tbc1d15 knockdown in vivo activates autophagy, reduces α-synuclein-mediated neurotoxicity, and improves motor performance in a mouse model of Parkinson's disease, consistent with TBC1D15 acting as an inhibitor of autophagic flux via Rab7 GAP activity. |
In vivo Tbc1d15 knockdown (mouse), autophagy flux assays, α-synuclein aggregate quantification, motor behavior testing |
bioRxivpreprint |
Low |
bio_10.1101_2024.10.01.616109
|