cytoskeleton

(redirected from Cytoskeletal)
Also found in: Dictionary, Thesaurus, Medical, Wikipedia.
Related to Cytoskeletal: actin, Cytoskeletal protein

Cytoskeleton

A system of filaments found in the cytoplasm of cells and responsible for the maintenance of and changes in cell shape, cell locomotion, movement of various elements in the cytoplasm, integration of the major cytoplasmic organelles, cell division, chromosome organization and movement, and the adhesion of a cell to a surface or to other cells.

Three major classes of filaments have been resolved on the basis of their diameter and cytoplasmic distribution: actin filaments (or microfilaments) each with an average diameter of 6 nanometers, microtubules with an average diameter of 25 nm, and intermediate filaments whose diameter of 10 nm is intermediate to that of the other two classes. The presence of this system of filaments in all cells, as well as their diversity in structure and cytoplasmic distribution, has been recognized only in the modern period of biology.

A technique that has greatly facilitated the visualization of these filaments, as well as the analysis of their chemical composition, is immunofluorescence applied to cells grown in tissue culture. See Immunofluorescence

Actin is the main structural component of actin filaments in all cell types, both muscle and nonmuscle. Actin filaments assume a variety of configurations depending on the type of cell and the state it is in. They extend a considerable distance through the cytoplasm in the form of bundles, also known as stress fibers since they are important in determining the elongated shape of the cell and in enabling the cell to adhere to the substrate and spread out on it. Actin filaments can exist in forms other than straight bundles. In rounded cells that do not adhere strongly to the substrate (such as dividing cells and cancer cells), the filaments form an amorphous meshwork that is quite distinct from the highly organized bundles. The two filamentous states, actin filament bundles and actin filament meshworks, are interconvertible polymeric states of the same molecule. Bundles give the cell its tensile strength, adhesive capability, and structural support, while meshworks provide elastic support and force for cell locomotion.

Microtubules are slender cylindrical structures that exhibit a cytoplasmic distribution distinct from actin filaments. Microtubules originate in structures that are closely associated with the outside surface of the nucleus known as centrioles. The major structural protein of these filaments is known as tubulin. Unlike the other two classes of filaments, microtubules are highly unstable structures and appear to be in a constant state of polymerization-depolymerization. See Centriole

Intermediate filaments function as the true cytoskeleton. Unlike microtubules and actin filaments, intermediate filaments are very stable structures. They have a cytoplasmic distribution independent of actin filaments and microtubules. In the intact cell, they anchor the nucleus, positioning it within the cytoplasmic space. During mitosis, they form a filamentous cage around the mitotic spindle which holds the spindle in a fixed place during chromosome movement.

cytoskeleton

[¦sīd·ō′skel·ə·tən]
(cell and molecular biology)
Protein fibers composing the structural framework of a cell.
References in periodicals archive ?
All cytoskeletal proteins displayed strong immunoreactivity (Table).
Adhesion phase occurring at long term contact involves various biological molecules like extracellular matrix proteins, cell membrane proteins and cytoskeletal proteins which interact together to induce signal transduction, promoting the action of transcription factors and consequently regulating gene expression (2).
The project has potential applications for a variety of fields, including smart materials, artificial muscle, understanding cytoskeletal mechanics and research into nonequilibrium physics, as well as DNA nanotechnology.
Michael Sheetz, James Spudich and Ronald Vale for discoveries concerning cytoskeletal motor proteins, machines that move cargoes within cells, contract muscles, and enable cell movements.
Eight papers examine these developments from such perspectives as clinical manifestations of hyper IgE syndromes, the essential role of DOCK8 in humoral immunity, DOCK8 immune deficiency as a model for primary cytoskeletal dysfunction, and epidermodysplasia verruciformis and the susceptibility to HPV.
Finally, treatment of the cells with PLE prevented UV-induced morphological changes in human fibroblasts, namely disorganisation of F-actin-based cytoskeletal structures, coalescence of the tubulin cytoskeleton and mislocalization of adhesion molecules such as cadherins and integrins.
Lyn seems to be a very potent signaling mediator in both epithelial and macrophage cell types and orchestrates many downstream pathways that regulate cytoskeletal changes for effective phagocytosis and increased expression of pro-inflammatory cytokines.
New to the 5th edition of this engaging textbook are sections on epigenetics, histone modifications, small RNAs, comparative genomics, genetic noise, cytoskeletal dynamics, cell-cycle control, and stem cells.
In addition, these drugs target tubulin, a cytoskeletal protein involved not only in mitosis and cell proliferation, but also in other important cellular functions.
pneumoniae strain isolated from bloody diarrhea can bind to HeLa cells and cytoskeletal proteins, such as the actin that accumulates at the point of bacterium-host contact (3).
ExoS includes a GTPase activating (GAP) domain located in the amino-terminus that affects Rho GTPases involved in cytoskeletal regulation.
2] can enhance platelet aggregation induced by collagen in the presence of fibrinogen via a rapid cytoskeletal reorganization consequent to tyrosine phosphorylation of [pp60.