Compartmentalization of some nuclear proteins in the interphase and mitosis. II. Immunocytochemical localization of 53 and 34 kDa nucleolar proteins in interphase and mitotic cells of the endosperm of wheat Triticum aestivum L.

摘要

Polypeptides with molecular weights of 53 and 34 kDa were identified in the total lysate of wheat root meristem cells by SDS-PAGE and Western blotting. The compartmentalization of these proteins was studied by light microscopic immunocytochemistry in interphase and mitotic endosperm cells. Both proteins were localized in the nucleoli of interphase cells. During mitosis the 53-kDa protein was found in the cytoplasm at prophase and was associated with the surface of chromosomes in early telophase. The 34-kDa protein was redistributed from the nucleolus to the karyoplasm and was associated with the surface of chromosomes from late prophase to telophase. In late telophase both proteins migrated into the newly forming nucleoli. The problem of the structural and biochemical similarity of the peripheral chromosomal material in animal and plant cells, and the role of this material and some nuclear proteins in the reorganization of the synthesis of rRNA after mitosis are discussed.