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Protein synthesis on the cytoskeleton
Abstract Number:1690 | Add this program to my agenda! |
Program Information
Session Number |
Session Name |
65 | Late and Moved Abstracts |
Presented by: Bratislav Stankovic, stankovic.1@osu.edu
Authors:
Stankovic, Bratislav | Department of Plant Biology, Ohio State University, Columbus, OH 43210, USA |
Davies, Eric | Botany Department, North Carolina State University, Raleigh, NC 27695, USA |
Abe, Shunnosuke | College of Agriculture, Ehime University, Tarumi, Matsuyama, Japan |
Relatively little is known about the existence and possible
function of cytoskeleton-bound polysomes (CBP) in plants, despite the recognition of the
fundamental role of the cytoskeleton in the sub-cellular transport and localization of
mRNAs in animals. However, trafficking and regulation of the translation of mRNAs on the
plant cytoskeleton might be expected since it has already been shown that wound-induced
inhibition and recovery in the rate of cytoplasmic streaming (an F-actin-dependent
process) correlates with the inhibition and recovery in the rate of protein synthesis.
Here we provide evidence from two different systems - the pea epicotyl and the maize
endosperm - for the existence and function of CBP in plants. Using biochemical cell
fractionation experiments in conjunction with variable-term, sucrose density gradient
centrifugation, we have identified 4 distinct populations of polysomes (free-,
membrane-bound-, cytoskeleton-bound-, and cytoskeleton-membrane-bound polysomes). Using in
vivo and in vitro radioactive labeling, we have compared the translational
efficiency of each of these populations of polysomes, in an attempt to understand whether
mRNA associated with the different populations of polysomes is preferentially translated.
Using fluorescence microscopy, we have shown associations between filamentous actin,
polysomes and protein bodies following homogenization of corn endosperm in a cytoskeletal
stabilizing buffer. Electron micrographs of tissue sections and isolated pellets processed
in a variety of ways suggest the existence of abundant 4-5 nm nanofilaments in etiolated
peas. The ribosomes seem to associate with these as well as with the normal
microfilaments. @ |