Tripartite Motif Containing Protein 54 (TRIM54)

TRIM54 contains a RING finger motif and is highly similar to the ring finger proteins RNF28/MURF1 and RNF29/MURF2. In vitro studies demonstrated that this protein, RNF28, and RNF29 form heterodimers, which may be important for the regulation of titin kinase and microtubule-dependent signal pathways in striated muscles. RNF30 shares 77% and 65% sequence identity with RNF28 and RNF29, respectively. All 3 proteins share a conserved N-terminal RING domain and zinc-binding B-box motif as well as 2 coiled-coil dimerization motif boxes in their central regions. In vitro, they form dimers/heterodimers by shared coiled-coil motifs. Dot-blot analysis demonstrated muscle-specific expression of RNF28 and RNF30, but low-level expression of RNF29 in liver in addition to expression in striated muscle.