| 2012 |
Human SAR1A (and SAR1B) lower the mechanical rigidity of membranes to which they bind in vitro, consistent with their role in sculpting highly curved COPII vesicles. At high concentrations, however, SAR1A increases bending rigidity and shows decreased protein mobility, implying that protein clustering governs membrane mechanical properties. |
Optical trap-based in vitro membrane deformation assay measuring bending rigidity |
Biochemical and biophysical research communications |
Medium |
22974979
|
| 2015 |
SAR1A GTPase dysfunction is the initiating event in ethanol-induced Golgi fragmentation in hepatocytes: loss of SAR1A activity impairs COPII vesicle formation, preventing ER-to-Golgi delivery of PDIA3 (protein disulfide isomerase A3), which in turn blocks giantin dimerization required for compact Golgi architecture. SAR1A gene silencing alone recapitulates this phenotype, arresting PDIA3 in the ER and causing large-scale Golgi fragmentation. |
siRNA knockdown of SAR1A in HepG2 cells and primary hepatocytes; immunofluorescence and Western blotting; ethanol-fed rat model |
Scientific reports |
Medium |
26607390
|
| 2018 |
Dominant-negative SAR1A mutants (T39N or H79G) reduce cell-surface expression of the cardiac sodium channel Nav1.5 and decrease peak sodium current density, establishing SAR1A as a regulator of Nav1.5 ER exit and trafficking. Simultaneous siRNA knockdown of SAR1A and SAR1B reduces current density, while single knockdown of either alone has minimal effect. Co-immunoprecipitation demonstrated that SAR1A physically interacts with MOG1, and SAR1A/SAR1B are required for MOG1-mediated increases in Nav1.5 surface expression. |
Dominant-negative overexpression, siRNA knockdown, patch-clamp electrophysiology (INa density), co-immunoprecipitation; HEK/Nav1.5 cells and neonatal rat cardiomyocytes |
Biochimica et biophysica acta. Molecular basis of disease |
Medium |
30251687
|
| 2018 |
The C-terminal region of Sec23A and Sec23B (effector proteins of SAR1A) specifically binds the active, GTP-bound form of SAR1A. A pull-down assay using recombinant C-terminal Sec23B shows that GTP-bound SAR1A increases during neuronal process elongation and oligodendroglial morphological differentiation. The GEF PREB (prolactin regulatory element binding protein) increases binding to the nucleotide-free (activated) form of SAR1A during morphological differentiation. |
Affinity precipitation (pull-down) using recombinant C-terminal Sec23B; differentiation of N1E-115 neuronal and FBD-102b oligodendroglial cell lines |
Biochemical and biophysical research communications |
Medium |
30078678
|
| 2022 |
TGF-β1 upregulates SAR1A expression in hypertrophic scar fibroblasts through a TAK1/JNK/p38 signaling axis (not the Smad3 or ERK pathway). siRNA knockdown of SAR1A suppresses procollagen-I secretion (but not collagen-1A mRNA expression), placing SAR1A downstream of TGF-β1/TAK1 signaling specifically in the post-translational secretory step. |
siRNA knockdown, kinase inhibitor pharmacology (TAK1, JNK, p38, Smad3, ERK inhibitors), Western blotting for procollagen-I secretion |
Open medicine (Warsaw, Poland) |
Medium |
36188194
|
| 2022 |
SAR1A knockdown in osteosarcoma cells impairs invasion and migration, reduces lamellipodia formation, suppresses epithelial-mesenchymal transition markers, and decreases YAP activity downstream of RhoA. Knockdown also enhances ER stress, reactive oxygen species, and autophagic flux, and reduces lung metastases in vivo, placing SAR1A upstream of the RhoA/YAP axis and ER homeostasis in osteosarcoma metastasis. |
siRNA knockdown, wound healing and Transwell invasion assays, phalloidin staining, Western blotting, immunofluorescence, in vivo lung metastasis model |
Cancer science |
Medium |
36047971
|
| 2024 |
Genetic inactivation of Sar1a in mice causes lethality during mid-embryogenesis, demonstrating an essential in vivo role for SAR1A in COPII-mediated ER-to-Golgi trafficking. Replacement of the Sar1b coding sequence with Sar1a at the endogenous Sar1b locus rescues the perinatal lethality of Sar1b-null mice and produces phenotypically normal adults, establishing near-complete functional overlap between SAR1A and SAR1B in vivo. |
Conditional and constitutive gene knockout in mice; knock-in of Sar1a coding sequence at Sar1b locus; adenovirus-mediated overexpression rescue; phenotypic analysis |
Proceedings of the National Academy of Sciences of the United States of America |
High |
38463989 38687799
|
| 2024 |
SAR1A overexpression in CHO cells reduces intracellular antibody accumulation (especially in the ER) and increases specific antibody production rate, demonstrating that SAR1A enhances COPII vesicle-mediated ER-to-Golgi transport. Overexpression also lowered antibody glycan galactosylation and induced stronger unfolded protein response at end of culture. |
Stable overexpression in CHO cells, chase assay with translation inhibitor, immunofluorescence imaging, LC-MS glycosylation profiling, UPR gene expression analysis |
Journal of bioscience and bioengineering |
Medium |
38806389
|
| 2025 |
SAR1A requires K27-linked oligo-ubiquitination to assemble the STING-COPII transport complex, which mediates STING trafficking from the ER to the Golgi apparatus. USP1 (a deubiquitinase) removes this ubiquitination from SAR1A, thereby blocking STING trafficking and type I interferon production. Pharmacological inhibition of USP1 (with ML323) sustains SAR1A ubiquitination, promotes COPII complex formation, and enhances STING-dependent innate immune signaling. |
Chemical screening, ubiquitination assays, USP1 inhibitor (ML323) treatment, Co-IP of STING-COPII complex, STING trafficking assays, IFN production measurements in tumor microenvironment models |
Advanced science (Weinheim, Baden-Wurttemberg, Germany) |
Medium |
39976106
|
| 2025 |
GLTP knockout alters the intracellular localization of SAR1A and of its activating GEF Sec12 at ER exit sites, suggesting that the GLTP/VAPA interaction modulates SAR1A activation state and COPII vesicle formation from the ER. |
GLTP knockout HeLa cells; immunofluorescence localization of SAR1A and Sec12; GLTP VAPA-binding mutant expression |
bioRxivpreprint |
Low |
bio_10.1101_2025.06.17.657375
|