Dynasore: Noncompetitive Dynamin GTPase Inhibitor for Endocytosis Research

Executive Summary: Dynasore is a cell-permeable, noncompetitive inhibitor of dynamin GTPase activity, with an IC₅₀ of 15 μM, blocking dynamin-dependent endocytosis in diverse cell types (Wang et al., 2018). It specifically targets dynamin1, dynamin2, and Drp1, crucial for vesicle trafficking and signal transduction. Dynasore reversibly inhibits transferrin uptake and synaptic vesicle endocytosis (APExBIO). It is insoluble in water but highly soluble in DMSO (≥16.12 mg/mL), requiring warming or sonication for optimal preparation. The compound is supplied by APExBIO (SKU: A1605) and is essential for dissecting endocytic mechanisms in cancer, neurodegeneration, and infectious disease models.

Biological Rationale

Dynamin GTPases are large mechanoenzymes required for membrane fission events during endocytosis, vesicle trafficking, and organelle division (Wang et al., 2018). Dynamin1 is predominantly neuronal, while dynamin2 and Drp1 are ubiquitous. Dynamin-dependent endocytosis is vital for signal transduction, nutrient uptake, and synaptic vesicle recycling. Disruption of these pathways is implicated in cancers and neurodegenerative diseases. Targeting dynamin GTPase activity enables researchers to probe the mechanistic basis of these physiological and pathological processes. Dynasore, by inhibiting dynamin1, dynamin2, and Drp1, allows reversible, acute suppression of endocytic vesicle scission, facilitating investigation of membrane trafficking and its role in cell biology. Prior reviews have summarized Dynasore's utility in neurobiology; this article updates recent benchmarks and clarifies specificity in viral entry models.

Mechanism of Action of Dynasore

Dynasore acts as a noncompetitive inhibitor of dynamin GTPase enzymes, binding allosterically rather than at the GTP-binding site (APExBIO). The reported IC₅₀ for dynamin inhibition is 15 μM under standard in vitro conditions (37°C, physiological buffer, 30 min incubation). By stabilizing the GDP-bound form, Dynasore impedes GTP hydrolysis, preventing the conformational changes required for vesicle neck constriction and fission. This blocks dynamin-mediated endocytosis without directly interfering with GTP binding or hydrolysis at other small GTPases. The inhibition is rapid-onset and reversible upon washout. Dynasore affects dynamin1, dynamin2, and Drp1, halting multiple dynamin-dependent processes such as clathrin-mediated endocytosis, synaptic vesicle recycling, and mitochondrial fission. For further reading on mechanistic nuances, consult this article, which delves into Dynasore's noncompetitive profile and comparisons to other inhibitors.

Evidence & Benchmarks

• Dynasore inhibits dynamin-dependent endocytosis in grass carp kidney (CIK) cells, reducing viral entry and infection by GCRV104 at 80 μM (Wang et al., 2018, DOI).
• Transferrin uptake is reversibly suppressed in HL-1 cells and neurons exposed to Dynasore at 80 μM for 30 min (APExBIO).
• Dynasore does not inhibit caveolin-mediated endocytosis or dynamin-independent pathways at standard concentrations (Wang et al., 2018, DOI).
• Synaptic vesicle endocytosis is acutely blocked in neuronal cultures, with recovery after Dynasore washout (internal article).
• Dynasore is insoluble in water and ethanol, but soluble in DMSO up to at least 16.12 mg/mL at 37°C (APExBIO).

This article clarifies the distinct selectivity and reversibility of Dynasore compared to other dynamin inhibitors, extending the evidence base beyond previous summaries (see here).

Applications, Limits & Misconceptions

Dynasore is widely applied in research involving:

• Dynamin-dependent endocytosis assays
• Vesicle trafficking pathway dissection
• Synaptic vesicle cycling in neurobiology
• Signal transduction pathway study in cancer and infectious disease models
• Viral entry inhibition in cell-based assays

Recent studies have leveraged Dynasore to dissect the entry mechanism of enveloped and non-enveloped viruses, confirming the requirement for dynamin-mediated endocytosis in multiple systems (Wang et al., 2018). Its rapid, reversible action allows temporal control and mechanistic dissection in live cell assays. For advanced protocol optimization and troubleshooting, see this guide, which Dynasore's robust performance in diverse cellular contexts.

Common Pitfalls or Misconceptions

• Dynasore does not inhibit caveolin- or clathrin-independent endocytosis at standard doses.
• It is ineffective against dynamin-independent viral entry mechanisms.
• Dynasore is not soluble in water or ethanol; DMSO is required for stock preparation.
• The compound is not intended for in vivo animal studies or clinical/diagnostic use.
• Prolonged exposure (>60 min) may lead to off-target effects; use minimal effective concentration and exposure time.

Workflow Integration & Parameters

For laboratory use, prepare Dynasore stock solutions in DMSO at ≥16.12 mg/mL. Warm to 37°C or sonicate for full dissolution. Store aliquots at -20°C for up to several months. Working concentrations typically range from 10 to 100 μM, with 30–60 min incubation in cell culture (37°C, physiological buffer). Washout enables reversible inhibition. Ensure experimental controls for DMSO vehicle and recovery post-inhibitor. For more detailed methodologies and advanced applications in vesicle trafficking and microbial vesicle biology, see this article, which also discusses Dynasore's translational research potential.

APExBIO supplies Dynasore (SKU: A1605) as a solid, research-use-only reagent. Product and safety details are available at the Dynasore product page.

Conclusion & Outlook

Dynasore remains the gold standard for acute, reversible inhibition of dynamin-dependent endocytosis and vesicle trafficking in cell models. Its specificity, rapid onset, and compatibility with diverse cell types underpin broad applications in endocytosis research, signal transduction pathway analysis, and disease modeling. Ongoing work is extending its use in cancer biology and neurodegenerative disease systems. Researchers should remain aware of its mechanistic selectivity, solubility requirements, and proper storage. For up-to-date protocols, benchmarks, and troubleshooting, APExBIO and peer-reviewed literature remain authoritative sources.