Microtubule-associated force-producing protein that is targeted to at the leading edges of the forming cell plate during cytokinesis (PubMed:18612642). Also plays a major role in plasma membrane maintenance and cell wall integrity with implications in vesicular trafficking, polar cell expansion, vascular formation, and other aspects of plant growth and development, including stigmatic papillae expansion (PubMed:18256049, PubMed:18344418). Collaboratively with DRP2B, participates in clathrin-coated vesicle formation during endocytosis (PubMed:20231465). Necessary for BOR1 polar localization in low-boron (B) conditions as well as for BOR1 endocytosis and subsequent degradation under high-concentration of boron (PubMed:27449211). Has a GTPase activity (PubMed:20171176). Required for the sterols-dependent dynamic high lipid order observed at the cell plate of dividing cells (PubMed:25234576). Together with SH3P2, converts the fused vesicles to tubular structures at the cell plate and phragmoplasts during cytokinesis (PubMed:28584166, PubMed:18256049). With DRP2B and PIP5K3, required for the precise coordination of polar ARAC3/ROP6 and ARAC4/ROP2 placement and subsequent root hair positioning during planar polarity formation in root hair-forming cells, probably by mediating the correct basal-to-planar polarity switching of D6PK into the polar, lipid-enriched domain (PubMed:27251533). Involved in endocytosis required for cellulose deposition during cell wall formation and elongation (PubMed:18256049). Interacts with plasma membrane-mimetic liposomes and induces their clustering (PubMed:20171176). GTP + H2O = GDP + H(+) + phosphate kcat is 28 min(-1) with GTP as substrate. Forms homodimer and may homooligomerize and heterooligomerize to form the phragmoplastin complex (PubMed:20171176, PubMed:20231465). Interacts with AGD3/VAN3. May interact with CALS1. Binds to AHK2. Binds to SH3P2 (PubMed:28584166). Forms a complex made of SH3P2 and DRP1A and triggers its accumulation at the cell plate (PubMed:28584166). Interacts with DRP2B at the plasma membrane and in forming clathrin-coated vesicles (CCV) (PubMed:20231465). Binds to PHIP1 (PubMed:18621982). Microtubule-associated and localized in the forming cell plate, at the vicinity of sterols, during cytokinesis, especially at the leading edges (PubMed:14750520, PubMed:28584166, PubMed:18612642, PubMed:25234576). Accumulates in a sterol-enriched, polar membrane domain during root hair initiation (PubMed:27251533). Forms discreet dynamic foci in the epidermal cell cortex, which colocalize with part of the clathrin endocytic machinery (PubMed:18344418). Co-localizes with BOR1 in the cell plate and the plasma membrane (PubMed:27449211). Ubiquitous. Expressed in leaves (at protein level). Vascular discontinuity (PubMed:15923323, PubMed:18344418). Short and swollen roots and hypocotyls due to cellulose-deficient walls associated with increased levels of arabinose, xylose, and galactose in non-cellulosic polysaccharides (PubMed:18256049). Infertility due to the inability of stigmatic papillae to undergo rapid polar expansion prior to fertilization (PubMed:18344418). The alteration of cell wall formation correlates with abnormal phragmoplasts and division plates in dividing cells, as well as reduced cell elongation and disturbed endocytosis (PubMed:18256049). Hypersensitivity to trafficking inhibitors (e.g. brefeldin A, monensin A and latrunculin B) (PubMed:18256049). Both basal and apical shift of ARAC3/ROP6 and ARAC4/ROP2 positioning and broad lateral localization of D6PK in root hair-forming cells leading to basal and apical shift of root hair positions (PubMed:27251533). Belongs to the TRAFAC class dynamin-like GTPase superfamily. Dynamin/Fzo/YdjA family.