Immunolocalisation of the cytoskeleton to plasmodesmata of Chara corallina

Abstract

SummaryThe macromolecular structure of plasmodesmata in the giant celled freshwater alga, Chara corallina, was examined using antibodies against cytoskeletal elements. The large internodal cells of Chara are separated by a nodal complex of smaller cells which are interconnected by plasmodesmata. Putative plasmodesmata-associated proteins can be identified by a comparison of proteins extracted from preparations of clean walls of nodal complexes and those extracted from the external walls of internodal cells which have no plasmodesmata. Actin and tubulin were identified in the protein extracts of nodal walls and the cytoplasm of nodes and internodes but not in the extracts of internodal external walls. Immunogold labelling confirmed the localisation of actin and myosin to plasmodesmata of Chara.

Ultrastructural study of plasmodesmata in the brown alga Dictyota dichotoma (Dictyotales, Phaeophyceae)

“…Several other works noted additional internal substructures (Ding et al 1992b, Overall and Blackman 1996. Recently, PD-associated proteins have been identified in charophycean algae and land plants , Blackman and Overall 1998, Gestel et al 2003, Faulkner et al 2005, Sagi et al 2005, Thomas et al 2008, Simpson et al 2009, Faulkner and Maule 2010. These works suggested that there are highly complicated control mechanisms underlying the cell-to-cell molecular traffic via PD.…”

AnArabidopsisGPI-Anchor Plasmodesmal Neck Protein with Callose Binding Activity and Potential to Regulate Cell-to-Cell Trafficking

“…Various approaches have been taken to identify such constituents, with limited success (reviewed in Oparka, 2004;Maule, 2008). The proteins identified include cytoskeletal elements (e.g., actin and myosin VIII) (Ding et al, 1996;Blackman and Overall, 1998;Reichelt et al, 1999), proteins associated with the endoplasmic reticulum (e.g., calreticulin) , a protein kinase 1 that phosphorylates Tobacco mosaic virus movement protein (Lee et al, 2005), a 1,3-b-glucanase (Levy et al, 2007b), a class 1 reversibly glycosylated protein (Sagi et al, 2005), and, recently, a receptor-like transmembrane protein located on the plasma membrane in Pds (Thomas et al, 2008). In this article, we report the identification of a family of small glycosylphosphatidylinositol (GPI)-linked proteins that exhibit specific callose binding activity in vitro and that localize to Pds as fluorescent protein fusions.…”

Plasmodesmata formation and cell-to-cell transport are reduced in decreased size exclusion limit 1 during embryogenesis in Arabidopsis

“…Cell-to-cell transport occurs through the cytoplasmic space between the plasma membrane and the DT (1,2,4) and also along the ER membrane of the DT (5). Actin and myosin may regulate PD aperture by forming helically arranged particles and spoke-like structures that connect the DT to the plasma membrane (6)(7)(8)(9)(10)(11).…”