Enables heat shock protein binding activity. Involved in leukocyte tethering or rolling; negative regulation of T cell proliferation; and positive regulation of T cell migration. Acts upstream of or within several processes, including positive regulation of macromolecule metabolic process; regulation of T cell activation; and regulation of defense response. Located in basement membrane; external side of plasma membrane; and uropod. Is expressed in hematopoietic system; umbilical artery; vascular system; and yolk sac. Orthologous to human SPN (sialophorin).
