Predicted to enable transcription coregulator activity. Predicted to be involved in regulation of transcription by RNA polymerase II. Predicted to act upstream of or within positive regulation of myotube differentiation and positive regulation of transcription by RNA polymerase II. Predicted to be active in nucleus. Orthologous to human MAMSTR (MEF2 activating motif and SAP domain containing transcriptional regulator). [provided by Alliance of Genome Resources, Apr 2022]