Enables proline-rich region binding activity. Predicted to be involved in RNA processing and regulation of transcription by RNA polymerase II. Predicted to act upstream of or within transcription, DNA-templated. Predicted to be located in nuclear matrix and nucleoplasm. Predicted to be active in nucleus. Is expressed in several structures, including branchial arch; limb bud; liver; metanephros; and pancreas epithelium. Orthologous to human TCERG1 (transcription elongation regulator 1). [provided by Alliance of Genome Resources, Apr 2022]