Binds to type I regulatory subunits of protein kinase A (PKA-RI) and may anchor/target them to the plasma membrane. Interacts with PKA type I regulatory subunits PRKAR1A and PRKAR1B. Also binds to type II regulatory subunits, but at a tenfold lower affinity (By similarity). Widely expressed, with very low levels in spleen and liver. May be palmitoylated at Cys-3. Belongs to the small membrane AKAP family.