| MURF 1 also binds to ubiquitin conjugating enzyme 9 and isopeptidase T 3 , enzymes involved in small ubiquitin related modifier mediated nuclear import , and with glucocorticoid modulatory element binding protein 1 ( GMEB 1 ) , a transcriptional regulator . ^^^ The dual interactions of MURF 1 with titin and GMEB 1 may link myofibril signaling pathways ( perhaps including titin ' s kinase domain ) with muscle gene expression . . ^^^ |