microtubule


Also found in: Dictionary, Thesaurus, Acronyms, Encyclopedia, Wikipedia.
Related to microtubule: Intermediate filaments

microtubule

 [mi″kro-tu´būl]
any of the slender, tubular structures, composed chiefly of tubulin, found in the cytoplasmic ground substance of nearly all cells; they are involved in maintenance of cell shape and in the movements of organelles and inclusions, and form the spindle fibers of mitosis.

mi·cro·tu·bule

(mī'krō-tū'byūl),
A hollow, cylindric cytoplasmic element, 25 nm in diameter and of variable length, that occurs widely in the cytoskeleton, cilia, and flagella of cells; microtubules play a role in the maintenance of cell shape and increase in number during mitosis and meiosis, in which they are related to movement of the chromosomes by the nuclear spindle.

microtubule

/mi·cro·tu·bule/ (mi″kro-too´būl) any of the slender, tubular structures composed chiefly of tubulin, found in the cytoplasmic ground substance of nearly all cells; they are involved in maintenance of cell shape and in the movements of organelles and inclusions, and form the spindle fibers of mitosis.
Enlarge picture
Microtubules in a 9 + 2 array in a cross-section of the axoneme of a cilium.

microtubule

(mī′krō-to͞o′byo͞ol, -tyo͞o-)
n.
Any of the cylindrical hollow tubulin-containing structures that are found in the cytoplasm, cilia, and flagella of eukaryotic cells and are involved in determining cell shape and structure and directing the movement of organelles and chromosomes. Microtubules, along with microfilaments and intermediate filaments, make up a cell's cytoskeleton.

mi′cro·tu′bu·lar adj.

microtubule

a hollow cylindrical structure (200 to 300 angstroms in diameter and of variable length) that occurs widely within plant and animal cells. Microtubules increase in number during cell division and are associated with the movement of deoxyribonucleic acid material. Compare microfilament.

microtubule

A cylindrical tube measuring 20–25 nm in diameter, composed of protofilaments which are in turn composed of alpha- and beta-tubulin polymers. Each microtubule is polarised: at one end (the negative (-) end), alpha-subunits are exposed; at the other end (the positive (+) end), beta-subunits are exposed. Microtubules act as a scaffolding to determine cell shape, and provide a matrix on which cell organelles and vesicles move, a process requiring motor proteins, including kinesin (which moves towards the (+) end of the microtubule) and dynein (which generally moves towards the (-) end). Microtubules also form the spindle fibres for separating chromosomes during mitosis.

mi·cro·tu·bule

(mī'krō-tū'byūl)
A cylindric cytoplasmic element that occurs widely in the cytoskeleton of plant and animal cells; microtubules increase in number during mitosis and meiosis, where they may be related to movement of the chromosomes or chromatids on the nuclear spindle during nuclear division.

microtubule

or

neurotubule

a hollow filament about 20–25 nm in diameter found in EUKARYOTE cells, composed of ACTIN-like protein called tubulin. Microtubules are thought to make up the CYTOSKELETON of the cell, the spindle fibres of MEIOSIS and MITOSIS, (See also COLCHICINE and, in some cells of plants and animals, form the 9 + 2 structure of the CILIUM and FLAGELLUM.

mi·cro·tu·bule

(mī'krō-tū'byūl)
A cylindric cytoplasmic element that occurs widely in the cytoskeleton of plant and animal cells; microtubules increase in number during mitosis and meiosis.

microtubule

(mī´krōtoo´būl),
n a hollow cylindrical structure that occurs widely within plant and animal cells. Microtubules increase in number during cell division and are associated with the movement of DNA material.

microtubule

any of the slender, tubular structures composed chiefly of tubulin, found in the cytoplasmic ground substance of nearly all cells; they are involved in maintenance of cell shape and in the movements of organelles and inclusions, and form the spindle fibers of mitosis.

microtubule-associated protein (MAP)
any of the high molecular weight proteins that bind to microtubules, enhancing polymerization.
microtubule-associated protein (MAP) kinase
a protein kinase that is activated in response to cell stimulation by many different growth factors and that mediates cellular responses by phosphorylating specific transcription factors and other target proteins.
microtubule organizing center (MTOC)
the location in a cell from which microtubules regrow after depolymerization. See also centrosome.
References in periodicals archive ?
A microtubule system arising from the NE-MTOC extends into the 4 lobes (Fig.
A conspicuous microtubule system assembles at the isthmus and extends to the plastid tips in the polar regions of the cell (Fig.
He and his colleagues designed the glass chips with 800-nanometer-deep channels in different traffic patterns, anchored kinesin molecules within the channels, and pumped in a solution of microtubules.
Physicists Travis Craddock and Jack Tuszynski of the University of Alberta, and anesthesiologist Stuart Hameroff of the University of Arizona have demonstrated a plausible mechanism for encoding synaptic memory in microtubules, major components of the structural cytoskeleton within neurons.
The EGFR inhibitor and microtubule stabilizer segments held the third and fourth largest shares of the market in terms of revenue in 2014.
It was earlier thought that, in order for chromosomes - packages containing DNA - to line up and be correctly separated, microtubules have to extend from specific microtubule-organising centres in the cell, called centrosomes.
Our 3D observation of metaphase spindles that self-organized in Xenopus egg extracts revealed that spindle shape and microtubule density were constant irrespective of spindle size, whereas spindle size was correlated with the microtubule amount.
As we now know, this very striking example is only one manifestation of the coordination of microtubule organization with the control of division plane in bryophyte meiosis.
New research presented February 19 shows that forces similar to those that cause traumatic brain injury can damage tiny conduits called microtubules.
elegans embryos have demonstrated that microtubule pulling forces cause the spindle to shift from the center of the embryo towards the posterior (Labbe et al.
Contributors overview compounds that interact with tubulin, then address molecular mechanisms, microtubule dynamics, post translational modification, isotypes, tubulin proteomics in cancer, structures, destabilization, molecular features of the interaction of colchicines and related structures with tubulin, mechanisms of resistant to drugs that interfere with microtubule assembly, microtubule damaging agents, microtubule targeting agents, and associations with tau proteins.
For example, students took a mid-term exam which included topics on microtubule polymerization and cell division covered in lecture.

Full browser ?