These parallel actin filaments are mainly elongated at their barbed-end by formins
and cross-linked by bundling proteins such as fascins.
Polymerization of nonfilamentous (G-) actin into filamentous (F-) actin and actin patch formation requires numerous signaling molecules such as the ARP2/3 complex, Cdc42 and formins (Ma et al.
Formins are large multi-domain proteins required for the assembly of straight actin filaments found in the cytokinetic contractile ring, yeast actin cables, adherens junctions between epithelial cells and filopodial protrusions (Chang et al.
Aside from formins, the Arp2/3 complex is another actin nucleator, which is a seven-subunit complex that includes two actin-related proteins 2 and 3 (Welch and Mullins, 2002).
Formins are critical for actin-based cellular processes.
Bezanilla and colleagues systematically silenced the many actin-regulating formins and determined which members of this protein family are needed to generate cells for proper tip growth.
By "swapping parts" from closely related formin proteins and measuring tip growing activity for each combination, her research group eventually concluded that only one intact subclass of formins drives normal growth and controls how the plant recognizes its growing tip.
are conserved actin-nucleating proteins that are involved in cytokinesis and cell polarity.
The researchers studied proteins called formins that help determine the shape of a cell during division and movement.
They identified a new mechanism for regulation of formins during cell division.
One of the cool things about these proteins is that they're tightly regulated - they will only do their jobs when they're told to do so," DeWard said, describing formins as the workers that put together the pieces that shape a cell.