Enables mRNA binding activity. Acts upstream of or within several processes, including mRNA splice site selection; negative regulation of excitatory postsynaptic potential; and negative regulation of mRNA splicing, via spliceosome. Located in cytoplasm and nucleus. Is expressed in several structures, including central nervous system; embryo ectoderm; mammary gland; retina; and spleen. Orthologous to human CELF4 (CUGBP Elav-like family member 4). [provided by Alliance of Genome Resources, Apr 2022]