Matrin 3 (MATR 3) is an internal nuclear matrix protein that may play a role in transcription or may interact with other nuclear matrix proteins to form the internal fibrogranular network. In association with the SFPQ-NONO heteromer MATR 3 may play a role in nuclear retention of defective RNAs. MATR3 forms part of complex consisting of SFPQ, NONO and MATR3. The protein contains 1 matrin type zinc finger and 2 RRM (RNA recognition motif) domains. Two transcript variants encoding the same protein have been identified for this gene.