Purification and immunological detection of pea nuclear intermediate filaments: evidence for plant nuclear lamins

A major structural component of the inner face of the nuclear envelope in vertebrates and invertebrates is the nuclear lamina, an array of 1-3 extrinsic membrane proteins, lamins A, B and C. These proteins are highly homologous to intermediate filaments and are classified as type V. We report the first purification, antigenic characterization and immunocytochemical localization of putative plant lamin proteins from pea nuclei. We conclude that plant cells contain this ancestral class of intermediate filaments in their nuclei and that regulation of nuclear envelope assembly/disassembly and mitosis in plants may be similar to that in animal cells.