Enables MRF binding activity. Acts upstream of or within several processes, including negative regulation of activation-induced cell death of T cells; negative regulation of skeletal muscle tissue development; and negative regulation of transcription by RNA polymerase II. Located in cytoplasm and nucleus. Is expressed in several structures, including early conceptus; genitourinary system; nervous system; sensory organ; and viscerocranium. Orthologous to human TSC22D3 (TSC22 domain family member 3). [provided by Alliance of Genome Resources, Apr 2022]