a protein comprising globular subunits which aggregate to form filaments, originally identified (in association with myosin) as a component of muscle cells, and later found in almost all eukaryotic cells, being involved in cell shape, adhesion, and motility, and the motion of intracellular components
Actin and myosin have been found in dozens of other (nonmuscle) cells and are believed to be responsible for the contractile properties of animal cells generally.
Hea teada
There are two forms, denoted by prefixed hyphenated capital letters: G-actin (‘globular’ actin) and F-actin (‘fibrous’ actin).