Microtubule-Organizing Centers and Nucleating Sites in Land Plants

摘要: Microtubule-organizing centers (MTOCs) are morphologically diverse cellular sites involved in the nucleation and organization of microtubules (MTs). These structures synonymous with centrosome mammalian cells. In most land plant cells, however, no such observed some have argued that cells may not MTOCs. This review summarizes a number experimental approaches toward elucidation those subcellular microtubule organization. lower plants, structurally well-defined MTOCs present, as blepharoplast, multilayered structure, polar organizer. higher much MTs occurs on nuclear envelope or other endomembranes, plasmalemma smooth (tubular) endoplasmic reticulum. instances, one endomembrane serve site whereas others Structural motor microtubule-associated proteins also appear to be MT Immunochemical evidence indicates at least several found centrosomes, gamma-tubulin, centrin, pericentrin, polypeptides recognized by monoclonal antibodies MPM-2, 6C6, C9 recognize putative MTOCs, indicating shared mechanisms nucleation/organization plants animals. The recent data from tubulin incorporation vivo, mutants altered organization, molecular studies indicate potential these research tools investigation plants.