Dynasore: Precision Dynamin GTPase Inhibitor for Endocytosis Research

Executive Summary: Dynasore (SKU: A1605, by APExBIO) is a cell-permeable, noncompetitive inhibitor of dynamin GTPases with an IC50 of 15 µM, specifically targeting dynamin1, dynamin2, and Drp1 to block endocytosis (APExBIO product page). Dynasore reversibly inhibits transferrin uptake and synaptic vesicle endocytosis, making it essential for dissecting vesicle trafficking and signal transduction (Zheng et al., 2024). It is insoluble in water and ethanol but dissolves in DMSO at ≥16.12 mg/mL and should be stored at -20°C for stability. This compound is widely used for cancer research, neurodegenerative disease models, and microbiome-host interaction studies. Limitations include lack of selectivity for non-dynamin GTPases and inapplicability in diagnostic contexts.

Biological Rationale

Endocytosis is a critical cellular process enabling internalization of nutrients, signaling molecules, and pathogens. Dynamin family GTPases (dynamin1, dynamin2, Drp1) mediate membrane scission events during endocytosis, vesicle trafficking, and organelle division. Dysregulation of dynamin-dependent pathways is implicated in cancer progression, neurodegenerative diseases, and host-microbiome interactions (Zheng et al., 2024). The tumor microbiome, notably Fusobacterium nucleatum, leverages vesicle trafficking for adhesion and colonization in colorectal cancer tissue, highlighting the importance of precise tools to dissect these pathways (Zheng et al., 2024).

Mechanism of Action of Dynasore

Dynasore is a small-molecule, reversible, noncompetitive inhibitor of dynamin GTPase activity. It binds to a site distinct from the GTP-binding pocket, thereby inhibiting GTP hydrolysis without competing with GTP substrate (APExBIO). The IC50 for dynamin GTPase inhibition is 15 µM under in vitro assay conditions (buffered at pH 7.4, 25°C). By inhibiting dynamin1, dynamin2, and Drp1, Dynasore prevents the fission of vesicles from cellular membranes, effectively blocking clathrin-mediated endocytosis and related trafficking processes (Article: 'Dynasore: Noncompetitive Dynamin GTPase Inhibitor...'). Its action is rapid and reversible, allowing precise temporal control in cellular experiments.

Evidence & Benchmarks

• Dynasore (≥80% purity) blocks transferrin uptake in HL-1 cells within 10 minutes at 80 µM, as measured by fluorescence microscopy (Zheng et al., 2024).
• In neuronal cultures, 100 µM Dynasore rapidly inhibits synaptic vesicle endocytosis, confirmed by decreased FM4-64 dye internalization within 5 minutes (see internal article).
• Dynasore prevents Fusobacterium nucleatum extracellular vesicle (FnEV) internalization in colorectal cancer cells, reducing bacterial adhesion and colonization in murine CRC models (Zheng et al., 2024).
• Dynasore is insoluble in water and ethanol but shows DMSO solubility ≥16.12 mg/mL at 37°C, requiring stock preparation in DMSO for optimal experimental use (APExBIO).
• Dynasore is stable for several months at -20°C when stored as a solid or DMSO stock (APExBIO).

Applications, Limits & Misconceptions

Dynasore is widely used to dissect endocytosis, vesicle trafficking, and GTPase signaling pathways. It enables studies of receptor-mediated endocytosis, viral entry, synaptic vesicle recycling, and tumor-microbiome interactions. Its rapid, reversible action allows for precise inhibition and washout protocols in live-cell assays. Dynasore's role is distinct from genetic knockdown, as it provides acute, temporal control and can be used in combination with imaging or functional readouts (see: 'Dynasore in Cancer and Microbiome Research'). This article updates prior content by focusing on the specificity and benchmarks validated in recent peer-reviewed studies.

Common Pitfalls or Misconceptions

• Dynasore does not inhibit all GTPases; its activity is selective for dynamin1, dynamin2, and Drp1.
• It is not suitable for diagnostic or therapeutic use in humans or animals.
• Dynasore is ineffective in water-based buffers; DMSO is required for solubilization.
• Long-term exposure (>30 min) may result in off-target effects; short, reversible treatments are recommended for specificity.
• Dynasore does not substitute for genetic knockout in long-term adaptation studies.

Workflow Integration & Parameters

Prepare a Dynasore stock solution in DMSO at ≥16.12 mg/mL by warming at 37°C or using sonication to enhance dissolution. For cell-based assays, dilute the stock into culture medium to final working concentrations (typically 20–100 µM), ensuring DMSO does not exceed 0.1–0.5% v/v to avoid cytotoxicity. Store stock solutions at -20°C for up to several months. Always include vehicle controls. For vesicle trafficking assays, treat cells for 5–30 minutes to achieve acute, reversible inhibition. For more detailed methods, see the APExBIO Dynasore product page and comparative protocols in 'Dynasore in Context: Precision Inhibition...' (which provides distinct application strategies from this article).

Conclusion & Outlook

Dynasore remains a validated, robust tool for dissecting dynamin-dependent endocytosis and vesicle trafficking in research models. Its reversible, noncompetitive inhibition profile and ease of use make it indispensable for cell biology, cancer, and microbiome-host signaling studies. Future research may expand its application to emerging areas such as nanoparticle uptake and precision modulation of the tumor microenvironment. For full product specifications and ordering, visit the APExBIO Dynasore (A1605) page.