actin


Also found in: Dictionary, Thesaurus, Acronyms, Encyclopedia, Wikipedia.
Related to actin: beta actin

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

/ac·tin/ (ak´tin) a muscle protein localized in the I band of the myofibrils; acting along with myosin, it is responsible for contraction and relaxation of muscle. It occurs in globular (G-actin) and fibrous (F-actin) forms.

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

a protein forming the thin filaments in muscle fibers that are pulled on by myosin cross-bridges to cause a muscle contraction. Some bacteria forms actin tails to use for motility. See also myosin.

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.
Figure 1: The autonomic nervous system. Actions on secretory functions (heart diagrams indicate release into the circulation). Sympathetic actions on the left and parasympathetic actions on the right. Solid arrows: stimulation (contraction or secretion); broken arrows: inhibition.

actin

globular protein molecule which readily links with others (with consumption of ATP) to form long, double-helical strands. Such actin filaments are found in a wide variety of animal and plant cells, as well as forming the structural core and main (but not only) component of the thin filaments in the myofibrils of all animal muscles. Actin is thus a protein of great evolutionary antiquity and vertebrate striated muscles are unusual only in having a very high content of it (80% of total protein), and in its highly ordered locations within the cells, where thin filaments alternate with thick filaments containing actin's partner protein myosin, to form the cross-striated pattern. See also muscle, muscle fibres; Figure 1.

actin (akˑ·tin),

n one of a pair of myofilaments involved in muscle contractions. See also myosin.

actin

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.

actin F
assembly of actin G monomers into filaments.
actin filaments
smallest filamentous proteins involved in a static role in cell structure and a dynamic role in cell movement.
actin G
monomeric globular protein which assembles into actin filaments.
References in periodicals archive ?
Figure 1A shows the model for the double-stranded structure of the actin filaments proposed by Hanson and Lowy (14) on the basis of electron microscopy.
Because actin itself is insufficiently stiff it cannot be manipulated like the previously mentioned systems, and the system must target myosin directly.
Protective effects of high-molecular weight Polyethylene Glycol (PEG) in human lung endothelial cell barrier regulation: role of actin cytoskeletal rearrangement," Microvascular Research, vol.
And while cytochalasin D might not be the actual agent scientists use to trigger bone formation in the clinic, Triggering actin transport into the nuclei of cells may be a good way to force mesenchymal stem cells to become bone cells.
But when we tried to slide actin filaments in two adjacent sarcomeres toward centers of respective sarcomeres as it is described in the sliding filament theory, the Z disc that was common to both sarcomeres was not able to move toward the center of either sarcomere (Figure 2).
The driving force for cell migration is provided by actin cytoskeleton polymerization, which induces membrane protrusion and pseudopod formation (Saarikangas et al.
The project leader Prof Inari Kursula said that the structures showed them that the two variants differ more from each other than actins in any other known living organism do and the high resolution enabled the researchers to identify areas within the proteins that cause the different behaviour.
Higher eukaryotic organisms express several actin genes however their primary structure is similar.
Robert Orchard, another study author, said: "By asking 'how does a bacterial pathogen from outside the cell regulate the host cells' actin dynamics within the cell?
The roles of the actin cytoskeleton have been widely studied in mouse oocytes.
This alteration in the physical structure is closely associated with the polymerization of globular or monomeric actin (G-actin) to filamentous actin (F-actin) that leads to secretion of substances into the surrounding medium [7].
TELECOMWORLDWIRE-19 September 2008-Energid releases latest version of Actin robotics toolkit(C)1994-2008 M2 COMMUNICATIONS LTD http://www.