Interaction of plant polysomes with the actin cytoskeleton

Protein composition and functional activity of various polysome subpopulations isolated from Vicia faba L. leaves and Triticum aestivum L. and Hordeum vulgare L. seedlings were studied. Membrane- and cytoskeleton-bound polysomes were more active in the wheat germ cell-free translational system than free polysomes. Several non-ribosomal proteins were detected in the polysome preparations by gel electrophoresis and Western blot analysis: (1) a canonical actin of mol wt 42 kDa; (2) a 40 kDa protein, demonstrating affinity for ribosomes, sharing some determinants with actin, and present predominantly in the subpopulations of bound polysomes; and (3) an acidic ribosome-associated p40 evenly distributed between free and bound polysomes. The possibility of involvement of these proteins in interactions between polysomes and the actin cytoskeleton is discussed.