Characterization of the unconventional myosin VIII in plant cells and its localization at the post-cytokinetic cell wall

• Published in: The Plant journal : for cell and molecular biology Vol. 19; no. 5; pp. 555 - 567
• Main Authors: Reichelt, S, Knight, A.E, Hodge, T.P, Baluska, F, Samaj, J, Volkmann, D, Kendrick-Jones, J
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 01.09.1999; Blackwell Science
• Subjects: actin; Arabidopsis; Arabidopsis - enzymology; Arabidopsis thaliana; Biological and medical sciences; Cell Communication; Cell kinetics; Cell physiology; cell wall components; cell walls; cytoskeleton; enzymology; Fluorescent Antibody Technique; Fundamental and applied biological sciences. Psychology; immunocytochemistry; Ion Channel Gating; Isoenzymes; Isoenzymes - physiology; Lepidium sativum; Microscopy, Confocal; Mitosis; motility; myosin; Myosins; Myosins - physiology; physiology; Plant physiology and development; Plant Roots; Plant Roots - enzymology; plasmodesmata; roots; Zea mays; Monocotyledones; Zea mays; Root; Immunocytochemistry; Mitosis; Intercellular transport; Structure function relationship; Cereal crop; Cell wall; Arabidopsis thaliana; Depolymerization; Cruciferae; Gramineae; Dicotyledones; Angiospermae; Coleoptile; Myosin; Plasmodesm; Cytoskeleton; Spermatophyta; Experimental plant; Localization
• ISSN: 0960-7412; 1365-313X
• DOI: 10.1046/j.1365-313x.1999.00553.x

Myosins are a large superfamily of motor proteins which, in association with actin, are involved in intracellular motile processes. In addition to the conventional myosins involved in muscle contractility, there is, in animal cells, a wide range of unconventional myosins implicated in membrane-associated processes, such as vesicle transport and membrane dynamics. In plant cells, however, very little is known about myosins. We have raised an antibody to the recombinant tail region of Arabidopsis thaliana myosin 1 (a class VIII myosin) and used it in immunofluorescence and EM studies on root cells from cress and maize. The plant myosin VIII is found to be concentrated at newly formed cross walls at the stage in which the phragmoplast cytoskeleton has depolymerized and the new cell plate is beginning to mature. These walls are rich in plasmodesmata and we show that they are the regions where the longitudinal actin cables appear to attach. Myosin VIII appears to be localized in these plasmodesmata and we suggest that this protein is involved in maturation of the cell plate and the re-establishment of cytoplasmic actin cables at sites of intercellular communication.