The keratin intermediate filament-like system in maize protoplasts

The application of Penman’s method of cell fractionation to plant protoplasts leads to our finding of keratin intermediate filament(IF)-like system in maize protoplasts, which was identified by using immunogold labelling with monoclonal antibody of cytokeratin from animal cells. Many gold particles were found to be bound on filaments, linked by 3 nm filaments. After further digestion and extraction with DNase I and ammonium sulphate, IF-like framework-lamina-nuclear matrix system was shown under electron microscope. That IF system exists in plant protoplasts just like in animal cells, and their main component is keratin-like protein.