SUN proteins form part of the LINC complex - a protein bridge that spans the nuclear envelope linking the nucleoskeleten to the actin cytoskeleten. They are located on the inner nuclear membrane side of the complex. The LINC complex is thought to function in controlling nuclear position, contributing to mechanical resistance and the overall architecture of the cell. SUN2 can exist in a heterodimer with SUN1. Both can interact with lamins and nesprins in the nuclear envelope.