Enables mRNA binding activity. Involved in T cell receptor signaling pathway; negative regulation of T-helper 17 cell differentiation; and regulation of miRNA metabolic process. Acts upstream of or within several processes, including hematopoietic or lymphoid organ development; lymphocyte homeostasis; and positive regulation of NIK/NF-kappaB signaling. Predicted to be located in cell surface; intracellular membrane-bounded organelle; and membrane. Predicted to be active in cytoplasmic stress granule. Orthologous to human RC3H2 (ring finger and CCCH-type domains 2). [provided by Alliance of Genome Resources, Apr 2022]