title: Plasmodesmata-associated proteins: can we see the whole elephant?
abstract: Encased in rigid cell walls, plant cells have evolved unique channel structures, plasmodesma (Pd), to create a pathway for molecular exchange between adjacent cells. Pd are basically cytoplasmic channels through the cell wall, which are lined by plasma membrane, and contain a modified strand of ER that spans them. These structures provide cytoplasmic and membrane continuity between connected cells, and that continuity is utilized for short and long distance molecular trafficking. Pd sphincters, made from constricting the Pd openings by outer layers of callose, together with the ER strand that occludes the Pd lumen set the upper limit for the size of molecules that can freely diffuse through the cytoplasmic component of the Pd channel. This limit, called the size exclusion limit (SEL), is a major factor that restricts macromolecular transport through Pd.
authors: Institute of Plant Science and Resources; Okayama University; Chuo, Kurashiki, Okayama Japan.
authors: Shoko
authors: S
authors: Ueki
authors: Department of Biochemistry and Cell Biology; State University of New York; Stony Brook, NY USA.
authors: Vitaly
authors: V
authors: Citovsky
mesh_terms: D007473:Ion Channels / Q000378:metabolism; D010539:Permeability; D010940:Plant Proteins / Q000378:metabolism*; D010944:Plants / Q000378:metabolism*; D031425:Plasmodesmata / Q000378:metabolism*
chemical_list: D007473:Ion Channels; D010940:Plant Proteins
keywords: Plasmodesmata; callose; reactive oxygen species; size exclusion limit; symplastic transport