actin

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actin

 [ak´tin]
a muscle protein localized in the I band of myofibrils; acting along with myosin particles, it is responsible for the contraction and relaxation of muscle fibers.

ac·tin

(ak'tin),
One of the protein components into which actomyosin can be split; it can exist in a fibrous form (F-actin) or a globular form (G-actin).

actin

(ăk′tĭn)
n.
A protein that forms the microfilaments of the eukaryotic cytoskeleton and plays an important role in cell movement, shape, and internal organization. In muscle cells, it functions with myosin to produce contraction.

Actin

One of two major muscle proteins—the other is myosin—which is an ATPase that binds to adenine nucleotides. In concert with myosin, actin is a filamentous protein responsible for muscle contraction, and has an active mechanicochemical role in cell function; it is divided into a 46-kD monomeric form, G-actin and a mature contractile form, F-actin, formed from G-actin polymers, capable of functioning in absence of myosin.

ac·tin

(ak'tin)
One of the protein components into which actomyosin can be split; it can exist in a fibrous form (F-actin) or a globular form (G-actin).

actin

A contractile protein in muscle, found in the thin filaments, to which the myosin cross-bridges bind. Actin filaments are also abundant inside all nucleated cells where they form the cytoskeleton, determining cell shape and, in the case of amoebic cells, cell movement. An actin contractile ring forms around the equator of a dividing cell at the end of MITOSIS and tightens so as to pinch the two daughter cells apart.

actin

a contractile protein found in the muscles of all animals from protozoa to vertebrates and in the MICROFILAMENTS of all cells. The energy for contraction is derived from ATP; See MYOSIN.
References in periodicals archive ?
This atomic model of the actin filament provides further understanding on the positioning of this protein in the actin-tropomyosin complex and on its relationship with troponin (Gordon et al.).
In the present study, a very thin layer of actin filament along the bulge surface was detected.
The disruption of actin filaments causes a decrease in the average elastic modulus of the cellular membrane.
It has been proposed that ABD2 can bind first to one F-actin filament, which in turn "activates"ABD1 and enables it to bind in a more ordered manner to another actin filament with a higher affinity [21].
Actin filaments are the tracks for myosin movement and their conformation affects myosin motility.
Our aim here was to demonstrate the mechanism regulating the change in polarity that leads to cell turning by focusing on the dynamics of FAs and bundled actin filaments called stress fibers (SFs) [34].
The toxin caused the actin filaments in the fish cells to collapse.
In our model, actin filaments can be manually slided over myosin filaments as is given in the sliding filament theory of muscle contraction and Z disc also move along with movement of actin filaments.
According to the literature, obzidan and verapamil are able to reduce the intracellular [Ca.sup.2+] ions concentration [8, 9], the content of which determines the depolymerization of actin filaments during the swelling among many cell types [10].
Microtubules (red) and actin filaments (purple) help give the synaptic bouton structure and move cargo around inside the neuron.
The assembly and disassembly of actin filaments, as well as their organizations into functional higher-order networks, are regulated by several actin-binding proteins, many of which are conserved from yeast to human [4, 5].