A Cellular Networking Model Involving Interactions Among Glycosyl-Phosphatidylinositol (GPI)-Anchored Plasma Membrane Arabinogalactan Proteins (AGPs), Microtubules and F-actin in Tobacco BY-2 Cells

Arabinogalactan-proteins (AGPs) are perhaps the most abundantly expressed set of proteins at the plant cell surface and play probable roles in cellular architecture and signaling. Although considerable progress has been made to understand the role of AGPs in plant growth and development, their exact functional roles and the molecular mechanisms underlying their interactions with either intra-or extra-cellular molecules are unknown. These unknown interactions were addressed in a recent research article in Plant Physiology. This study reported molecular interactions between AGPs and the cytoskeleton [microtubules, (MTs) and F-actin] in tobacco BY-2 cells. Here in this addendum, a summary of this recent publication and additional perspectives are presented. As reported, perturbation studies were conducted in tobacco BY-2 cells to analyze the effects of an AGP inhibitor (b-Yariv reagent) on the organization of microtubules [labeled by GFP-MBD (green fluorescent protein-microtubule binding domain)] and F-actin (labeled by rhodamine-phalloidin) and conversely to analyze the effects of a microtubule inhibitor (amiprophosmethyl) and an F-actin inhibitor (cytochalasin-D) on the localization of GPI-anchored GFP-LeAGP-1. These studies implicate a role for GPI-anchored LeAGP-1 in mediating a cell wall-plasma membrane-cytoskeleton connection.