Binds to actin and affects the structure of the cytoskeleton. At high concentrations, profilin prevents the polymerization of actin, whereas it enhances it at low concentrations. By binding to PIP2, it inhibits the formation of IP3 and DG. Inhibits androgen receptor (AR) and HTT aggregation and binding of G-actin is essential for its inhibition of AR (By similarity). Interacts with VASP. Occurs in many kinds of cells as a complex with monomeric actin in a 1:1 ratio. Found in a complex with XPO6, Ran, ACTB and PFN1 (By similarity). Interacts with HTT (By similarity). Phosphorylation at Ser-138 reduces its affinity for G-actin and blocks its interaction with HTT, reducing its ability to inhibit androgen receptor (AR) and HTT aggregation. Belongs to the profilin family.