Actins are highly conserved proteins that are involved in various types of cell motility and are ubiquitously expressed in all eukaryotic cells (PubMed:11449050). Essential component of cell cytoskeleton; plays an important role in cytoplasmic streaming, cell shape determination, cell division, organelle movement and extension growth (PubMed:11449050). This is considered as one of the vegetative actins which is involved in the regulation of hormone-induced plant cell proliferation and callus formation (PubMed:11449050). Required for the trafficking and endocytic recycling of ABCG36/PEN3 between the trans-Golgi network and the plasma membrane in root epidermal and cap cells (PubMed:27803190). Polymerization of globular actin (G-actin) leads to a structural filament (F-actin) in the form of a two-stranded helix. The binding of profilin to monomeric G-actin cause the sequestration of actin into profilactin complexes, and prevents the polymerization. Constitutively expressed at high levels in young expanding vegetative tissues. Also strongly expressed in the hypocotyl and seed coat. Little or no expression is detected in mature pollen sacs, ovules, embryos or seeds. Differentially regulated in response to exogenous hormone treatment. In particular, auxin is a strong inducer. Impaired trafficking and endocytic recycling of ABCG36/PEN3 between the trans-Golgi network and the plasma membrane in root epidermal and cap cells. There are 8 actin genes in A.thaliana. Belongs to the actin family.