Phospho-DNM1 (Ser774) Antibody is a rabbit polyclonal antibody generated against a synthesized peptide spanning residues 740–789 of human Dynamin 1, encompassing the phosphorylated S774 site . It is validated for use in:
Dynamin 1 is a neuron-specific GTPase critical for clathrin-mediated endocytosis (CME) and activity-dependent bulk endocytosis (ADBE) . Its phosphorylation at S774 (and S778) regulates interactions with BAR domain proteins like syndapin, enabling membrane remodeling during high-intensity neuronal activity . Key findings include:
Phospho-Dependent Interactions: Dephosphorylation of S774 triggers Dynamin 1 binding to syndapin, a step essential for ADBE but not CME . Mutants mimicking phosphorylation (e.g., DynI dmE-mCer) block syndapin binding and inhibit FM1-43 dye uptake (a marker for ADBE) .
Kinase Regulation: S774 phosphorylation is mediated by cyclin-dependent kinase 5 (cdk5) and glycogen synthase kinase 3 (GSK3) . Progesterone-induced Ca²⁺ signaling in spermatozoa enhances S774 phosphorylation, which is abolished by dynasore (a dynamin inhibitor) .
Splice Variant Specificity: Dynamin 1xA, a splice variant with a unique C-terminal extension, requires S774/S778 dephosphorylation for ultrafast endocytosis via Endophilin A1 binding .
Western Blot: Detects endogenous phospho-DNM1 (S774) in rat brain lysates (Fig. 1) .
Functional Studies:
Localization Studies: Colocalizes with Endophilin A1 at synaptic endocytic zones, as shown by super-resolution microscopy .
Specificity: No cross-reactivity with non-phosphorylated DNM1 or other dynamin isoforms (e.g., DNM2) .
Interference: Phospho-mimetic peptides (e.g., DynI 769–784EE) do not block antibody binding, ensuring accurate detection .
Controls: Include non-phosphorylated lysates or peptide competition assays to confirm signal specificity .