title: Phragmoplastin dynamics: multiple forms, microtubule association and their roles in cell plate formation in plants.
abstract: We have characterized 4 of the 16 members of the family of dynamin-related proteins (DRP) in Arabidopsis. Three members, DRP1A (previously referred as ADL1), DRP1C and DRP1E, belong to the largest group of phragmoplastin-like proteins. DRP2A (ADL6) is one of the two members that contain a pleckstrin homology (PH) domain and a proline-rich (PR) motif, characteristics of animal dynamins. All four proteins interacted in yeast two-hybrid assays with phragmoplastin, and showed different patterns of localization at the forming cell plate during cytokinesis. GFP-tagged DRP1A and DRP1C proteins were found to be associated with the cytoskeleton in G1 phase of the cell cycle. The distribution pattern of DRP1A was sensitive to propyzamid and insensitive to cytochalasin D, suggesting that DRP1A is associated with microtubules and not actin filaments. The association of DRP1A with microtubules was confirmed in vitro by spin-down assays. A GTPase-defective phragmoplastin acted as a dominant negative mutant, reduced transport of vesicles to the cell plate and formed dense tubule-like structures in the cell plate. We propose that DRP1 proteins may provide an anchor for Golgi-derived vesicles to attach to microtubules, which in turn direct the vesicles to the forming cell plate during cytokinesis. Whereas the DRP1 subfamily members are involved in tubulization of membranes, DRP2 may be involved in endocytosis and membrane recycling via clathrin-coated vesicles.
authors.affiliation: Department of Molecular Genetics, Department of Plant Biology, and Plant Biotechnology Center, Ohio State University, 240 Rightmire Hall, 1060 Carmack Road, Columbus, OH 43210-1002, USA.
authors.forename: Zonglie
authors.initials: Z
authors.lastname: Hong
authors.forename: C Jane
authors.initials: CJ
authors.lastname: Geisler-Lee
authors.forename: Zhongming
authors.initials: Z
authors.lastname: Zhang
authors.forename: Desh Pal S
authors.initials: DP
authors.lastname: Verma
mesh_terms: D000199:Actins / Q000378:metabolism; D000595:Amino Acid Sequence; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D002455:Cell Division / Q000502:physiology; D002460:Cell Line; D019281:Dimerization; D020558:GTP Phosphohydrolases / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008540:Meiosis; D018613:Microscopy, Confocal; D008854:Microscopy, Electron; D008870:Microtubules / Q000378:metabolism*; D009154:Mutation; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D011485:Protein Binding; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D021381:Protein Transport; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D013170:Spores / Q000235:genetics; D014026:Nicotiana / Q000166:cytology / Q000235:genetics / Q000648:ultrastructure; D014162:Transfection
chemical_list: D000199:Actins; D029681:Arabidopsis Proteins; D008164:Luminescent Proteins; D010940:Plant Proteins; D020033:Protein Isoforms; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; C098512:phragmoplastin protein, plant; D020558:GTP Phosphohydrolases