| Abstract Detail
Cell Walls Sardar, Harjinder S. [1], Showalter, Allan M. [2]. Interactions of arabinogalactan-proteins (AGPs) with molecular components of the cytoskeleton, plasma membrane and cell wall in tobacco (BY-2) cells. Arabinogalactan-proteins (AGPs), a superfamily of plant hydroxyproline-rich glycoproteins are present at cell surfaces and widely implicated in plant growth and development. A well characterized classical tomato AGP, LeAGP-1 was used to elucidate functional roles of AGPs. Tobacco BY-2 cells stably expressing GFP-LeAGP-1 were plasmolysed to localize LeAGP-1 on plasma membrane and Hechtian strands. Cytoskeleton disruptors and ß-Yariv reagent (which binds and perturbs AGPs) were used to examine the role of LeAGP-1 as a candidate linker protein between plasma membrane and cytoskeleton. This study used a two-pronged approach. First, BY-2 cells, either WT or expressing GFP-MBD (microtubule binding domain), were treated with ß-Yariv reagent and effects on microtubules (MTs) and F-actin were observed. Second, BY-2 cells expressing GFP-LeAGP-1 were treated with amiprophosmethyl (APM) and cytochalasin-D, to disrupt MTs and F-actin, and effects on LeAGP-1 localization were observed. ß-Yariv treatment resulted in terminal cell bulging and depolymerization/disorganization of MTs, indicating a likely role for AGPs in cortical MT organization. ß-Yariv treatment also resulted in the formation of thicker actin filaments, indicating a role for AGPs in actin polymerization. Similarly, APM and cytochalasin-D treatments resulted in relocalization of LeAGP-1 on Hechtian strands and indicate roles for MTs and F-actin in AGP organization at the cell surface and in Hechtian strands. These studies indicated that GPI-anchored AGPs function to link the plasma membrane to the cytoskeleton [(Sardar HS, Showalter AM. Plant Physiology 142: 1469-1479 (2006); Sardar HS, Showalter AM. Plant Signaling and Behavior 2(1): 8-9 (2007)]. To further examine specific interactions between AGPs and other molecular components in the plasma membrane, cell wall and cytoplasm, cross-linking experiments are being conducted with homobifunctional membrane permeable and impermeable chemical cross-linkers using whole cell, plasma membrane (PM) and detergent-resistant membrane (DRM) fractions
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1 - Ohio University, Department of Environmental & Plant Biology; Molecular and Cellular Biology Program
2 - Ohio University, Department of Environmental & Plant Biology; Molecular and Cellular Biology Program, Porter Hall, Athens, OH, 45701, USA
Keywords:
Arabinogalactan-protein
Hechtian strands
Yariv reagent
microtubules
F-actin
amiprophosmethyl
cytochalasin-D
GFP-LeAGP1
GFP-MBD.
Presentation Type: Plant Biology Abstract
Session: P
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM
Number: P17026
Abstract ID:1266 |
