E3 Ubiquitin ligase protien 1

Accession #/Synonyms: Q969Q1; Tripartite motif-containing protein 63; muscle specific RING finger protein, RING finger protein 28, Striated muscle RING Zn finger protein, Iris RING finger protein, TRIM63; .

RING domain in proteins is a zinc finger motif which serves as a protein-protein interaction interface. The muscle specific RING finger protein (MURF-1) that binds specifically to tintin repeats A168/A169 adjecent to the tintin kinase domain of the giant myofibrillar protein (1). There are 3 genes encoding three different type of muscle specific RING finger proteins (MURF1-3).  Muscles adapts to decrease loads and activity by undergoing atrophy.  Though in rat atrophy model majority of the genes are up-regulated, but interestingly, two sets of genes (MURF1 and MAFbx) both encode for E3 ubiquitin ligases.  Knockout mice for MURF1 and MAFbx (Atrogin) exhibit resistance to muscle atrophy in quadriceps muscle after lesion of its innervation (2).  Both MURF1 and MAFbx are potential therapeutic targets for muscle atrophy.   

E3 ubiquitin ligase. regulates proteasomal degradation of cardiac troponin I/TNNI3 and probably of other sarcomeric-associated proteins.  E3 ubiquitin ligase can be classified into two types based on their mechanism of transferring ubiquitin to the substrate. One type, which comprises most E3s, contains a Ring motif (or the related U-box motif) and facilitates transfer of the activated ubiquitin directly from the E2 to the substrate. The second type contains a HECT domain, which forms a thioester intermediate with ubiquitin and then transfers the ubiquitin to the substrate (3).  Eukaryotic cells contain a large number of different E3s (probably hundreds), and each E3 is believed to recognize only a limited number of proteins as substrates.  In most cases the E3 recognizes a specific structure or amino acid sequence in the substrate (often termed the “degron”) (3). For example, the “N-end rule” E3, Ubr-1, recognizes particular types of amino acids at the N terminus of the substrates (4), whereas the E3 SCFCdc4 complex recognizes a specific phosphorylated amino acid sequence in its substrate, Sic1 (4).

MURF- selective antibodies were generated against peptides form unique regions on MURF1 protein corresponding to amino acid 274-293 near the C-terminal end of protein. This region was not only antigenic but also lies on the surface of the protein in native or in partially denatured MURF1 confirmation.  The anti-MURF1antibodies are fully characterized for applications in western blotting and ELISA at the recommended dilutions.  The MURF1antibodies are affinity purified on an immobilized antigen based affinity matrix, the isolated antibodies were then stabilized in antibody stabilization buffer for long-term storage.  FabGennix Int. Inc. provides MURF1 Western blot positive control samples in “ready-to-use” SDS-PAGE sample buffer.  Limited quantities of antigenic blocking peptide for MURF1 antibody is also available, please inquire before ordering.  FabGennix Int. Inc., will also conjugate this antibody to fluorophores and other secondary enzymes at a nominal price.

For research use only, not for diagnostic or therapeutic use.