- Muscle-specific RING finger-1 interacts with titin to regulate sarcomeric M-line and thick filament structure and may have nuclear functions via its interaction with glucocorticoid modulatory element binding protein-1. McElhinny, A.S., Kakinuma, K., Sorimachi, H., Labeit, S., Gregorio, C.C. J. Cell Biol. (2002)