actin filament

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Related to actin filament: Intermediate filament, myosin filament


1. a delicate fiber or thread.
2. in an x-ray tube, the wire (cathode) that makes electrons available for interaction with the anode when it is heated to incandescence to form an electron cloud.
actin filament one of the thin contractile filaments in a myofibril, composed mainly of actin; each actin filament is surrounded by three myosin filaments.
myosin filament one of the thick contractile filaments in a myofibril, composed mainly of myosin; each myosin filament is surrounded by six actin filaments.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

ac·tin fil·a·ment

one of the contractile elements in muscular fibers and other cells; in skeletal muscle, the actin filaments are about 7.5 nm wide and 1 mcm long, and attach to the transverse Z filaments.
Synonym(s): thin filament
Farlex Partner Medical Dictionary © Farlex 2012

Actin Filament

A long, slender chain of G-actin which transmits tension in muscles, participates in cell protrusion, and acts as scaffolding for binding dozens of different molecules. Actin filaments (AFs) can withstand molecular forces, but are highly sensitive to gelsolin.
Gelsolin cleaves AFs with almost surgical precision; gelsolin-actin cleavage is strictly regulated; micromolar concentrations of Ca2+ or a low pH cause gelsolin to sever; certain phosphoinositides inhibit severing, and may release gelsolin and allow AF growth. By EM, AFs are attached at one end to the Z bands and at the other interdigitate with myosin filaments.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.

ac·tin fil·a·ment

(ak'tin fil'ă-mĕnt)
One of the contractile elements in muscular fibers and other cells; in skeletal muscle, the actin filaments are about 5 nm wide and 100 mcm long; they attach to the transverse Z filaments.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012
References in periodicals archive ?
Myosin II is an adenosine triphosphate (ATP)dependent protein that generates force and movement along the actin filaments. The "swinging lever-arm" hypothesis of muscle contraction purposes that nucleotide-dependent small movements of the ATPase catalytic site are amplified by the rotation of the myosin molecule "neck", and it is accepted as the general mechanism by which the sarcomere shortening occurs (Shiroguchi et al., 2011).
Considering that actin filaments are assembled by noncovalent interactions, this provides a higher potential of exchange between the monomeric and the filamentous states.
Hanein, "An atomic model of actin filaments cross-linked by fimbrin and its implications for bundle assembly and function," The Journal of Cell Biology, vol.
(40)-(42) The geometric arrangement of the actin filament interaction with myosin molecules that are attached to a large scanning probe affects the shape of the potential.
Myosin V is thought to bind a vesicle at its tail and transport the vesicle by moving processively, step by step along an actin filament without dissociation.
Associated with this, AJs are disrupted in these cells, which is mediated by the inactivation of merlin, a member of the ezrin, radixin, and moesin (ERM) family of proteins that links actin filaments to AJ complexes [116].
Caption: FIGURE 2: Effect of TNF-[alpha] on actin filament organization.
The protrusion, named troponin arm, associated intimately with the actin filament. It covered the region where three actin protomers (monomers) meet.
Ono, "Mechanism of depolymerization and severing of actin filaments and its significance in cytoskeletal dynamics," International Review of Cytology, vol.