MuRF1, is a nuclear protein that interacts with SMT3b and the large myofibrillar protein Titin. In muscle cells, MuRF2 (RFN29) regulates gene expression and protein turnover. It localizes to the cytoplasm, but under atrophic conditions it is detected in the nucleus. MuRF2 can form oligomers with various other proteins, including Titin and Myosin. MuRF3, also designated tripartite motif-containing 54 (TRIM54) or ring finger protein 30 (RNF30), interacts with tubulin and stabilizes microtubules duing myotube formation. It is a cytoplasmic protein the localizes to the Z-lines in skeletal muscles, while MuRF2 localizes to the sarcomeric M-band in cardiomyocytes. MuRF3 shares 77% and 65% sequence identity with MuRF1 and MuRF2, respectively. MuRF1-3 share a conserved N-terminal RING domain and zinc-binding B-box motif, and two coiled-coil dimerization motif boxes, in their central regions.