Pre-mRNA binding protein, binds avidly to poly(G) and poly(U) RNA homopolymers. Involved in splicing. Acts as a receptor for carcinoembryonic antigen in Kupffer cells, may initiate a series of signaling events leading to tyrosine phosphorylation of proteins and induction of IL-1 alpha, IL-6, IL-10 and tumor necrosis factor alpha cytokines. Identified in the spliceosome C complex (By similarity). Interacts with PPIA/CYPA (By similarity). Expressed in all tissues tested, including liver, heart, lung, skeletal muscle, kidney, stomach, large intestine, small intestine, pancreas, spleen, peritoneal macrophage and thyroid. Sumoylated.