Binds F-actin and nucleates actin assembly. Major high affinity link between the plasma membrane and the cortical actin network. Monomer. Preferentially localized in some actin-rich membrane structures. Must span the plasma membrane, probably via beta-strands. High expression during growth and early development which drops precipitously during cell streaming at circa 8 hours of development. Disulfide bond(s) stabilize the native, actin-binding conformation of ponticulin. The GPI-like-anchor contains a phosphoceramide group, rather than a phosphatidyl group. Membranes isolated from axenically grown null cells have no detectable F-actin binding activity. Belongs to the ponticulin family. The Dictyosteliida are known to produce a glycosylsphingolipidinositol anchor (GPI-like-anchor). It has not been established whether Dictyosteliida make a glycosylphosphatidylinositol anchor (GPI-anchor) also, and whether their GPI-like-anchor modifications can be interconverted with GPI-anchor modifications in a resculpting process. It has not been established that the GPI-like-anchor modification in Dictyosteliida utilizes the same sequence motif.