Mechanics of motor proteins and the cytoskeleton pdfLouis, Missouri , USA. Kinesins and myosins are motor proteins that can move actively along microtubules and actin filaments, respectively. Plants have evolved a unique set of motors that function as regulators and organizers of the cytoskeleton and as drivers of long-distance transport of various cellular components. Recent progress has established the full complement of motors encoded in plant genomes and has revealed valuable insights into the cellular functions of many kinesin and myosin isoforms. Interestingly, several of the motors were found to functionally connect the two cytoskeletal systems and thereby to coordinate their activities. In this review, we discuss the available genetic, cell biological, and biochemical data for each of the plant kinesin and myosin families from the context of their subcellular mechanism of action as well as their physiological function in the whole plant. We particularly emphasize work that illustrates mechanisms by which kinesins and myosins coordinate the activities of the cytoskeletal system.
Mechanics of motor proteins and the cytoskeleton
In fact, J. Once stems or roots reach nearly vertical orientation during gravitropic responses, myosin XI is required to set up the initial cell polarization and the focusing of actin filaments to a single spot for tip growth Author information Copyright and License information Disclaimer.
Brady. The fundamental function of both kinesin and myosin motor proteins is the generation of mechanical force along cytoskeletal elements. A further clue for the involvement of MyoB proteins in organelle motility comes from the overexpression of isolated DUF that presumably cannot associate with organelles.
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Physics of bio-molecules and cells. Motor proteins are molecular machines that convert the chemical energy derived from the hydrolysis of ATP into mechanical work used to power cellular motility. In addition to specialized motile cells like muscle fibers and cellular processes like cilia, all eukaryotic cells contain motor proteins Fig. The reason is that eukaryotic cells are large and their cytosols are crowded with filaments and organelles; as a result, diffusion is too slow to efficiently move material from one part of a cell to another Luby-Phelps et al. Instead, the intracellular transport of organelles such as vesicles, mitochondria, and chromosomes is mediated by motor proteins. These proteins include myosins and dyneins that are relatives of the proteins found in the specialized muscle and ciliated cells, as well as members of a third family of motor proteins, the kinesins, which are distantly related to the myosin family. Unable to display preview.
However, and plant height was further strengthened in a recent study that directly manipulated organelle movement speeds, it remains to be seen whether KCBP-b directly or indirectly contributes chtoskeleton this chloroplast movement. The paucity of genome information from Polypodiopsida ferns and gymnosperms does not allow for any inferences about subfunctionalization of myosin genes prior to the emergence of angiosperms. Inter-dependence of dimerization and organelle binding in myosin XI.
It is currently not clear how myosin activity contributes to cell and ultimately plant growth.