Poster: Cytoskeleton structure & dynamics
Abs #
682: Molecular interactions of arabinogalactan-proteins (AGPs) with cortical microtubules and actin in bright yellow 2 (BY-2) tobacco cultured cells
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Presenter: |
Sardar, Harjinder S., hs238102@ohio.edu |
Authors | Sardar, Harjinder S. (A) Showalter, Allan M. (A) | | Affiliations: |
(A): Ohio University
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Arabinogalactan-proteins (AGPs) are plant proteoglycans that belong to a superfamily of hydroxyproline-rich glycoproteins. AGPs are expressed at plant cell surfaces and are known to have a wide taxonomic distribution in the plant kingdom. Although the specific functional nature of AGPs is still elusive, they are widely implicated in plant growth and development. A novel modular tomato AGP, LeAGP-1 is well characterized and at our disposal for elucidating functional roles of AGPs. Perturbation studies involving treatment with cytoskeleton disruptors and Yariv reagent are in progress at the cellular level using tobacco BY-2 cells. These studies will serve to examine the role of Le-AGP1 as a candidate linker protein between the plasma membrane and cytoskeleton. Two transgenic tobacco BY-2 cell lines are being used to conduct these studies. A transgenic BY-2 cell line stably expressing GFP-LeAGP1 was salt plasmolysed (4%) and used to establish the localization of LeAGP-1 on the plasma membrane and in Hechtian strands (connecting strands between the cell wall and plasma membrane). In this cell line, a F-actin inhibitor, cytochalasin-D, disorganized the Hechtian strands and thus suggested a role for F-actin filaments in organizing LeAGP-1 at the cell surface. Another BY-2 transgenic cell line stably expressing GFP-MBD (microtubule binding domain) (produced and supplied by Dr.Richard Cyr, PSU) was used to study the interaction of AGPs with cortical microtubules. This cell line, following a 5 hr treatment with 5mM b-Yariv reagent (a synthetic red dye that selectively binds to AGPs), results in the disorganization and depolymerization of microtubules and thus reveals a likely role for AGPs in the organization of cortical microtubules.
