Actin cytoskeleton in plants: From transport networks to signaling networks
✍ Scribed by Volkmann, Dieter; Balu?ka, Franti?ek
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 371 KB
- Volume
- 47
- Category
- Article
- ISSN
- 1059-910X
No coin nor oath required. For personal study only.
✦ Synopsis
The plant actin cytoskeleton is characterized by a high diversity in regard to gene families, isoforms, and degree of polymerization. In addition to the most abundant F-actin assemblies like filaments and their bundles, G-actin obviously assembles in the form of actin oligomers composed of a few actin molecules which can be extensively cross-linked into complex dynamic meshworks. The role of the actomyosin complex as a force generating system -based on principles operating as in muscle cells -is clearly established for long-range mass transport in large algal cells and specialized cell types of higher plants. Extended F-actin networks, mainly composed of F-actin bundles, are the structural basis for this cytoplasmic streaming of high velocities On the other hand, evidence is accumulating that delicate meshworks built of short F-actin oligomers are critical for events occurring at the plasma membrane, e.g., actin interventions into activities of ion channels and hormone carriers, signaling pathways based on phospholipids, and exo-and endocytotic processes. These unique F-actin arrays, constructed by polymerization-depolymerization processes propelled via synergistic actions of actin-binding proteins such as profilin and actin depolymerizing factor (ADF)/cofilin are supposed to be engaged in diverse aspects of plant morphogenesis. Finally, rapid rearrangements of F-actin meshworks interconnecting endocellular membranes turn out to be especially important for perceptionsignaling purposes of plant cells, e.g., in association with guard cell movements, mechano-and gravity-sensing, plant host-pathogen interactions, and wound-healing.