E3 ubiquitin ligase. Regulates proteasomal degradation of cardiac troponin I/TNNI3 and probably of other sarcomeric-associated proteins. May play a role in striated muscle atrophy and hypertrophy by regulating an anti-hypertrophic PKC-mediated signaling pathway. May regulate the organization of myofibrils through TTN in muscle cells.
Muscle specific. Selectively expressed in heart and skeletal muscle. Also expressed in the iris.
Protein modification; protein ubiquitination.
Contains 1 B box-type zinc finger. Contains 1 COS domain. Contains 1 RING-type zinc finger.
Expressed throughout all developmental stages.
The RING-type zinc finger mediates interaction with SUMO2 and localization to the nucleus. Also required for the E3 ubiquitin ligase activity.
Cytoplasm. Nucleus. Localizes to the M- and Z-lines in skeletal muscle. Colocalizes with TNNI3 in myocytes.
MacNeil LG et al. The order of exercise during concurrent training for rehabilitation does not alter acute genetic expression, mitochondrial enzyme activity or improvements in muscle function. PLoS One9:e109189 (2014).
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Bailey AN et al. MAFbx, MuRF1, and the stress-activated protein kinases are upregulated in muscle cells during total knee arthroplasty. Am J Physiol Regul Integr Comp Physiol303:R376-86 (2012).
Read more (PubMed: 22761181) »